Contents - XJ JEEPS
The Motor Manual Guy
Contents
Introductory pages
About this manual
Introduction to the Jeep Cherokee and Comanche
Vehicle identification numbers
Buying parts
Maintenance techniques, tools and working facilities
Booster battery (jump) starting
Jacking and towing
Automotive chemicals and lubricants
Safety first!
Conversion factors
Troubleshooting
0-5
0-5
0-7
0-10
0-10
0-17
0-17
0-19
Q-20
0-21
0-22
Chapter 1
Tune-up and routine maintenance
1
1-1
Chapter 2 Part A
Four-cylinder engine
2A-1
Chapter 2 Part B
V6 engine
28-0
2B
2C-0
2c.·
Chapter 2 Part C
lnline six-cylinder engine
Chapter 2 Part D
General engine overhaul procedures
2D-0
2D
Chapter 3
Cooling, heating and air conditioning systems
3-1
3
4-0
4
5-1
5
Chapter 4
Fuel and exhaust systems
Chapters
Engine electrical systems
Chapters
Emissions and engine control systems
6-1
Chapter 7 Part A
Manual transmission
7A-1
.'6
1t,.·····
Chapter 7 Part B
Automatic transmission
Chapter 7 Part C
Transfer case
7C-0
Chapter 8
Clutch and drivetrain
8-0
Chapter 9
Brakes
9-0
Chapter 10
Suspension and steering systems
10-1
Chapter 11
Body
11-1
Chapter 12
Chassis electrical system
12-0
Wiring diagrams
12-9
Index
7B
7B-1
IMD-1
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The Motor Manual Guy
Vehicle identification numbers
Modifications are a continuing and unpublicized process in vehicle
manufacturing. Since spare parts manuals and lists are compiled on
a numerical basis, the individual vehicle numbers are essential to correctly identify the component required.
of production, the Gross Vehicle Weight Rating (GVWR) and the certification statement.
Vehicle ldentification Number (VIN)
This plate is located on the radiator support on the driver's side. It
contains information on the vehicle model, emission certification, engine
and transmission type as well as the paint code.
This very important identification number is stamped on a plate attached to the left side of the dashboard just inside the windshield on
the driver's side of the vehicle (see illustration). The VIN also appears
on the Vehicle Certificate of Title and Registration. It contains information such as where and when the vehicle was manufactured, the model
year and the body style.
Safety Certification label
The Safetv Certification label is affixed to the left front door pillar.
The plate contains the name of the manufacturer, the month and year
Vehicle Identification Plate
Engine identification number
The engine ID number on four-cylinder engines is located on a machined surface on the right side of the block between the number three
and four cylinders (see illustration). On V6 engines, the ID number is
located on a pad at the front of the block (see illustration). On inline
six-cylinder engines, the ID number is located on a machined surface
on the right side of the block between the number t w o and three
cylinders (see illustration).
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Four-cylinder engine ID number location
The Vehicle ldentification Number (VIN) is visible from outside
the vehicle through the driver's side of the windshield
V6 engine ID number location
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lnline six-cylinder engine ID number location
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The build date and serial number are stamped on the
bottom of the AX 4/5 manual transmission case
BA 1015 manual transmission ID number location
TRANSMISSION
NUMBER
DATE
NUMBER
1-363
The three-speed automatic transmission numbers are
stamped on the edge of the left side of the case
Typical transfer case ID tag
The four-speed automatic transmission ID plate is on the
right rear side of the case
Front axle ID number location
The Motor Manual Guy
Vehicle identification numbers
Transmission identification number
BUILD DATE
AND
MANUFACTURER NO.
The ID number on T 415 manual transmissions is located on a tag
attached to the rear of the case. On AX 415 manual transmissions,
there are two identification codes: a model/code shipping date stamped
on the shift tower and an eight digit code stamped on the bottom surface of the case (see illustration). On the BA 1015 manual transmission,
the ID plate is attached to the left side of the front case (see illustration).
On three-speed automatic transmissions the ID numbers are stamped
on the left edge of the case (see illustration). The ID plate on fourspeed automatic transmissions is located on the right rear of the case
(see illustration).
Transfer case identification number
On most models the transfer case identification plate is located on
the left rear side of the case (see illustration).
Axle identification numbers
On most front axles the identification number is located on a tag
attached to the differential housing cover (see illustration). On rear
0-9
I.D.
LOCATION
Rear axle number locations
axles, the identification tag is on the left side of the housing and the
build date and manufacturer number are stamped on the axle tube (see
illustration).
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Maintenance techniques, tools and working facilities
Fastener sizes
For a number of reasons, automobile manufacturers are making wider
and wider use of metric fasteners. Therefore, it is important t o be able
t o tell the difference between standard (sometimes called U.S. or SAE)
and metric hardware, since they cannot be interchanged.
All bolts, whether standard or metric, are sized according to diameter,
thread pitch and length. For example, a standard 1/2 - 13 x 1 bolt
is 1 /2 inch in diameter, has 1 3 threads per inch and is 1 inch long.
An M 1 2 - 1.75 x 2 5 metric bolt is 1 2 m m in diameter, has a thread
pitch of 1.75 m m (the distance between threads) and is 2 5 m m long.
The t w o bolts are nearly identical, and easily confused, but they are
not interchangeable.
In addition t o the differences in diameter, thread pitch and length,
metric and standard bolts can also be distinguished by examining the
bolt heads. To begin with, the distance across the flats on a standard
bolt head is measured in inches, while the same dimension on a metric
bolt is sized in millimeters (the same is true for nuts). As a result, a
Grade 1 or 2
standard wrench should not be used on a metric bolt and a metric
wrench should not be used on a standard bolt. Also, most standard
bolts have slashes radiating out from the center of the head t o denote
the grade or strength of the bolt, which is an indication of the amount
of torque that can be applied t o it. The greater the number of slashes,
the greater the strength of the bolt. Grades 0 through 5 are commonly
used on automobiles. Metric bolts have a property class (grade) number,
rather than a slash, molded into their heads t o indicate bolt strength.
In this case, the higher the number, the stronger the bolt. Property class
numbers 8.8, 9.8 and. 10.9 are commonly used on automobiles.
Strength markings can also be used t o distinguish standard hex nuts
from metric hex nuts. Many standard nuts have dots stamped into one
side, while metric nuts are marked w i t h a number. The greater the
number of dots, or the higher the number, the greater the strength of
the nut.
Metric studs are also marked on their ends according t o property
class (grade). Larger studs are numbered (the same as metric bolts),
Grade 8
Grade 5
Bolt strength markings (top - standard/SAE/USS; bottom - metric)
Grade
Identification
Class
Hex Nut
Property
Class 9
Hex Nut
Grade 5
3 Dots
I
6 Dots
Standard hex nut strength
markings
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Arabic 9
Hex Nut
Property
Class 1 0
Hex Nut
Grade 8
Identification
@
Arabic 10
Metric hex nut strength
markings
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CLASS
10.9
CLASS
9.8
CLASS
8.8
Metric stud strength markings
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0-12
Maintenance techniques, tools and working facilities
while smaller studs carry a geometric code to denote grade.
It should be noted that many fasteners, especially Grades 0 through
2, have no distinguishing marks on them. When such is the case, the
only way to determine whether it is standard or metric is to measure
the thread pitch or compare it to a known fastener of the same size.
Standard fasteners are often referred to as SAE, as opposed to
metric. However, it should be noted that SAE technically refers to a
non-metric fine thread fastener only. Coarse thread non-metric
fasteners are referred to as USS sizes.
Since fasteners of the same size (both standard and metric) may have
different strength ratings, be sure to reinstall any bolts, studs or nuts
removed from your vehicle in their original locations. Also, when replacing a fastener with a new one, make sure that the new one has
a strength rating equal to or greater than the original.
Tightening sequences and procedures
Most threaded fasteners should be tightened to a specific torque
value (torque is the twisting force applied to a threaded component
such as a nut or bolt). Overtightening the fastener can weaken it and
cause it to break, while undertightening can cause it to eventually come
loose. Bolts, screws and studs, depending on the material they are made
of and their thread diameters, have specific torque values, many of
which are noted in the Specifications at the beginning of each Chapter.
Be sure to follow the torque recommendations closely. For fasteners
not assigned a specific torque, a general torque value chart is presented
here as a guide. These torque values are for dry (unlubricated) fasteners
threaded into steel or cast iron (not aluminum). As was previously mentioned, the size and grade of a fastener determine the amount of torque
that can safely be applied to it. The figures listed here are approximate
Metric thread sizes
Ft-lb
6 to 9
M-6
M-8
M-10
M-12
M-14
14
28
50
80
to
to
to
to
21
40
71
140
Nmlm
9 to 12
19 to 28
38 to 54
68 to 96
109 to 154
Pipe thread sizes
118
114
318
1/2
5 to 8
12 to 18
22 to 33
25 to 35
7 to 10
17 to 24
30 to 44
34 to 47
6 to 9
12 to 18
14 to 20
22 to 32
27 to 38
40 to 55
40 to 60
55 to 80
9 to 12
17 to 24
19 to 27
30 to 43
37 to 51
55 to 74
55 to 81
75 to 108
U.S. thread sizes
114 - 20
5/16
18..
511 6 - 2 4 .
318 - 1 6 . .
318 - 2 4 .
7/16 - 1 4 . .
7/16 - 2 0 .
112 - 1 3 . .
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Standard (SAE and USS) bolt dimensionslgrade marks
G
L
T
D
Grade marks (bolt strength)
Length (in inches)
Thread pitch (number o f threads per inch)
Nominal diameter (in inches)
Metric bolt dimensionslgrade marks
P
L
T
D
Property class (bolt strength)
Length (in millimeters)
Thread pitch (distance between threads i n millimeters)
Diameter
The Motor Manual Guy
Maintenance techniques, tools and working facilities
for Grade 2 and Grade 3 fasteners. Higher grades can tolerate higher
torque values.
a pattern, such as cylinder head bolts, oil pan
Fasteners laid out
bolts, differential cover bolts, etc., must be loosened or tightened in
sequence t o avoid warping the component. This sequence will normally be shown in the appropriate Chapter. If a specific pattern is not
given, the following procedures can be used t o prevent warping.
Initially, the bolts or nuts should be assembled finger-tight only. Next,
they should be tightened one full turn each, a criss-cross or diagonal
pattern. After each one has been tightened one full turn, return t o the
first one and tighten them all one-half turn, following the same pattern. Finally, tighten each of them one-quarter turn at a time until each
fastener has been tightened t o the proper torque. To loosen and remove
the fasteners, the procedure would be reversed.
Component disassembly
Component disassembly should be done w i t h care and purpose t o
help ensure that the parts go back together properly. Always keep track
o f the sequence in which parts are removed. Make note of special
characteristics or marks on parts that can be installed more than one
way, such as a grooved thrust washer on a shaft. It is a good idea
t o lay the disassembled parts out on a clean surface in the order that
they were removed. It may also be helpful t o make sketches or take
instant photos of components before removal.
When removing fasteners from a component, keep track of their locations. Sometimes threading a bolt back in a part, or putting the washers
and nut back on a stud, can prevent mix-ups later. If nuts and bolts
cannot b e returned t o their original locations, they should be kept in
a compartmented box or a series of small boxes. A cupcake or muffin
tin is ideal for this purpose, since each cavity can hold the bolts and
nuts from a particular area (i.e. oil pan bolts, valve cover bolts, engine
mount bolts, etc.). A pan of this type is especially helpful when working on assemblies with very small parts, such as the carburetor, alternator, valve train or interior dash and trim pieces. The cavities can be
marked w i t h paint or tape t o identify the contents.
Whenever wiring looms, harnesses or connectors are separated, it
is a good idea t o identify the t w o halves with numbered pieces of masking tape so they can be easily reconnected.
Gasket sealing surfaces
Throughout any vehicle, gaskets are used t o seal the mating surfaces between t w o parts and keep lubricants, fluids, vacuum or
pressure contained in an assembly.
Many times these gaskets are coated with a liquid or paste-type
gasket sealing compound before assembly. Age, heat and pressure can
sometimes cause the t w o parts t o stick together so tightly that they
are very difficult t o separate. Often, the assembly can be loosened by
striking it w i t h a soft-face hammer near the mating surfaces. A regular
hammer can be used if a block of wood is placed between the hammer
and the part. Do not hammer on cast parts or parts that could be easily
damaged. With any particularly stubborn part, always recheck t o make
sure that every fastener has been removed.
Avoid using a screwdriver or bar t o pry apart an assembly, as they
Micrometer set
0-13
can easily mar the gasket sealing surfaces of the parts, which must
remain smooth. If prying is absolutely necessary, use an old broom
handle, but keep in mind that extra clean u p will be necessary if the
wood splinters.
After the parts are separated, the old gasket must be carefully
scraped off and the gasket surfaces cleaned. Stubborn gasket material
can be soaked w i t h rust penetrant or treated w i t h a special chemical
t o soften it so it can be easily scraped off. A scraper can be fashioned
from a piece of copper tubing by flattening and sharpening one end.
Copper is recommended because it is usually softer than the surfaces
t o be scraped, which reduces the chance of gouging the part. Some
gaskets can be removed with a wire brush, but regardless of the method
used, the mating surfaces must be left clean and smooth. If for some
reason the gasket surface is gouged, then a gasket sealer thick enough
t o fill scratches will have t o be used during reassembly of the components. For most applications, a non-drying (or semi-drying) gasket
sealer should be used.
Hose removal tips
Warning: If the vehicle is equipped with air conditioning, do not disconnect any of the A/C hoses without first having the system depressurized
by a dealer service department or an air conditioning specialist,
Hose removal precautions closely parallel gasket removal precautions. Avoid scratching or gouging the surface that the hose mates
against or the connection may leak. This is especially true for radiator
hoses. Because o f various chemical reactions, the rubber in hoses can
bond itself t o the metal spigot that the hose fits over. To remove a
hose, first loosen the hose clamps that secure it t o the spigot. Then,
w i t h slip-joint pliers, grab the hose at rhe clamp and rotate it around
the spigot. Work i t back and forth until i t is completely free, then pull
it off. Silicone or other lubricants will ease removal if they can be
applied between the hose and the outside of the spigot. Apply the same
lubricant t o the inside of the hose and the outside o f the spigot t o
simplify installation.
As a last resort (and if the hose is t o be replaced w i t h a n e w one
anyway), the rubber can be slit w i t h a knife and the hose peeled from
the spigot. If this must be done, be careful that the metal connection
is not damaged.
If a hose clamp is broken or damaged, d o not reuse it. Wire-type
clamps usually weaken w i t h age, so it is a good idea t o replace them
w i t h screw-type clamps whenever a hose is removed.
Tools
A selection of good tools is a basic requirement for anyone who plans
t o maintain and repair his or her o w n vehicle. For the owner w h o has
f e w tools, the initial investment might seem high, but when compared
t o the spiraling costs of professional auto maintenance and repair, it
is a wise one.
Dial indicator set
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Maintenance techniques, tools and working facilities
0-14
Dial caliper
Hand-operated vacuum pump
Timing light
Compression gauge with spark plug
hole adapter
Damper/steering wheel puller
General purpose puller
Hydraulic lifter removal tool
Valve spring compressor
Valve spring compressor
Ridge reamer
Piston ring groove cleaning tool
Ring removal/installation tool
0-15
Maintenance techniques, tools and working facilities
Ring compressor
Cylinder hone
Brake cylinder hone
Clutch plate alignment tool
Brake hold-down spring tool
pue
Tap
die set
To help the owner decide which tools are needed to perform the tasks
detailed in this manual, the following tool lists are offered:
Maintenance and minor repair, Repair/overhaul and Special.
The newcomer to practical mechanics should start off with the
maintenance and minor repair tool kit, which is adequate for the simpler
jobs performed on a vehicle. Then, as confidence and experience grow,
the owner can tackle more difficult tasks, buying additional tools as
they are needed. Eventually the basic kit will be expanded into the repair
and overhaul tool set. Over a period of time, the experienced do-ityourselfer will assemble a tool set complete enough for most repair
and overhaul procedures and will add tools from the special category
when it is felt that the expense is justified by the frequency of use.
Note: If basic tune-ups are going to
part of routine maintenance,
it will
necessary to purchase a good quality stroboscopic timing light
and combination tachometer/dwell meter. Although they are included
in the list of special tools, it is mentioned here because they are
absolutely necessary for tuning most vehicles properly.
Maintenance and minor repair tool kit
Repair and overhaul tool set
The tools in this list should be considered the minimum required for
performance of routine maintenance, servicing and minor repair work.
We recommend the purchase of combination wrenches (box-end and
open-end combined in one wrench). While more expensive than open
end wrenches, they offer the advantages of both types of wrench.
These tools are essential for anyone who plans to perform major
repairs and are in addition to those in the maintenance and minor repair
tool kit. Included is a comprehensive set of sockets which, though
expensive, are invaluable because of their versatility, especially when
various extensions and drives are available. We recommend the
112-inch drive over the 318-inch drive. Although the larger drive is bulky
and more expensive, it has the cap:icity of accepting a very wide range
of large sockets. Ideally, however, the mechanic should have a 3/8-inch
drive set and a 1/2-inch drive set.
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Socket set(s)
Reversible ratchet
Extension - 10 inch
Universal joint
Torque wrench
size drive
sockets)
Ball peen hammer
8 ounce
Soft-face hammer (plastic/rubber)
Standard screwdriver (1/4-inch x 6 inch)
Standard screwdriver (stubby - 5/16-inch)
Phillips screwdriver (No. 3 8 inch)
No. 2)
Phillips screwdriver (stubby
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Combination wrench set (1/4-inch to 1 inch or 6 mm to 19 mm)
Adjustable wrench, 8 inch
Spark plug wrench with rubber insert
Spark plug gap adjusting tool
Feeler gauge set
Brake bleeder wrench
Standard screwdriver (5/16-inch x 6 inch)
Phillips screwdriver (No. 2 x 6 inch)
Combination pliers - 6 inch
Hacksaw and assortment of blades
Tire pressure gauge
Grease gun
Oil can
Fine emery cloth
Wire brush
Battery post and cable cleaning tool
Oil filter wrench
Funnel (medium size)
Safety goggles
Jackstands (2)
Drain pan
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The Motor Manual Guy
0-16
Maintenance techniques, tools and working facilities
Pliers - vise grip
Pliers - lineman's
Pliers - needle nose
Pliers - snap-ring (internal and external)
Cold chisel - 1/2-inch
Scribe
Scraper (made from flattened copper tubing)
Centerpunch
Pin punches (1 /16, 1/8, 3/16-inch)
Steel rule/straightedge - 12 inch
Allen wrench set (1/8 to 3/8-inch or 4 mm to 10mm)
A selection of files
Wire brush (large)
Jackstands (second set)
Jack (scissor or hydraulic type)
Note: Another tool which is often useful is an electric drill motor with
a chuck capacity of 3/8-inch and a set of good quality drill bits.
Special tools
The tools in this list include those which are not used regularly, are
expensive to buy, or which need to be used in accordance with their
manufacturer's instructions. Unless these tools will be used frequently,
it is not very economical to purchase many of them. A consideration
would be to split the cost and use between yourself and a friend or
friends. In addition, most of these tools can be obtained from a tool
rental shop on a temporary basis.
This list primarily contains only those tools and instruments widely
available to the public, and not those special tools produced by the
vehicle manufacturer for distribution to dealer service departments.
Occasionally, references to the manufacturer's special tools are inluded
in the text of this manual. Generally, an alternative method of doing
the job without the special tool is offered. However, sometimes there
is no alternative to their use. Where this is the case, and the tool cannot
be purchased or borrowed, the work should be turned over to the dealer
service department or an automotive repair shop.
Valve spring compressor
Piston ring groove cleaning tool
Piston ring compressor
Piston ring installation tool
Cylinder compression gauge
Cylinder ridge reamer
Cylinder surfacing hone
Cylinder bore gauge
Micrometers and/or dial calipers
Hydraulic lifter removal tool
Bal/joint separator
Universal-t ype puller
Impact sere wdriver
Dial indicator set
Stroboscopic timing light (inductive pick-up)
Hand operated vacuum/pressure pump
Tachometer/dwell meter
Universal electrical multimeter
Cable hoist
Brake spring removal and installation tools
Floor jack
Buying tools
For the do-it-yourselfer who is just starting to get involved in vehicle
maintenance and repair, there are a number of options available when
purchasing tools. If maintenance and minor repair is the extent of the
work to be done, the purchase of individual tools is satisfactory. If,
on the other hand, extensive work is planned, it would be a good idea
to purchase a modest tool set from one of the large retail chain stores.
A set can usually be bought at a substantial savings over the individual
tool prices, and they often come with a tool box. As additional tools
are needed, add-on sets, individual tools and a larger tool box can be
purchased t o expand the tool selection. Building a tool set gradually
allows the cost of the tools to be spread over a longer period of time
and gives the mechanic the freedom to choose only those tools that
will actually be used.
Tool stores will often be the only source of some of the special tools
that are needed, but regardless of where tools are bought, try to avoid
cheap ones, especially when buying screwdrivers and sockets, because
they won't last very long. The expense involved in replacing cheap
tools will eventually be greater than the initial cost of quality tools.
Care and maintenance of tools
Good tools are expensive, so it makes sense to treat them with
respect. Keep them clean and in usable condition and store them properly when not in use. Always wipe off any dirt, grease or metal chips
before putting them away. Never leave tools lying around in the work
area. Upon completion of a job, always check closely under the hood
for tools that may have been left there so they won't get lost during
a test drive.
Some tools, such as screwdrivers, pliers, wrenches and sockets, can
be hung on a panel mounted on the garage or workshop wall, while
others should be kept in a tool box or tray. Measuring instruments,
gauges, meters, etc. must be carefully stored where they cannot be
damaged by weather or impact from other tools.
When tools are used with care and stored properly, they will last
a very long time. Even with the best of care, though, tools will wear
out if used frequently. When a tool is damaged or worn out, replace
it. Subsequent jobs will be safer and more enjoyable if you do.
Working facilities
Not to be overlooked when discussing tools is the workshop. If
anything more than routine maintenance is to be carried out, some sort
of suitable work area is essential.
It is understood, and appreciated, that many home mechanics do
not have a good workshop or garage available, and end up removing
an engine or doing major repairs outside. It is recommended, however,
that the overhaul or repair be completed under the cover of a roof.
A clean, flat workbench or table of comfortable working height is
an absolute necessity. The workbench should be equipped with a vise
that has a jaw opening of at least four inches.
As mentioned previously, some clean, dry storage space is also
required for tools, as well as the lubricants, fluids, cleaning solvents,
etc. which will soon become necessary.
Sometimes waste oil and fluids, drained from the engine or cooling
system during normal maintenance or repairs, present a disposal problem. To avoid pouring them on the ground or into a sewage system,
pour the used fluids into large containers, seal them with caps and take
them to an authorized disposal site or recycling center. Plastic jugs,
such as old antifreeze containers, are ideal for this purpose.
Always keep a supply of old newspapers and clean rags available.
Old towels are excellent for mopping up spills. Many mechanics use
rolls of paper towels for most work because they are readily available
and disposable. To help keep the area under the vehicle clean, a large
cardboard box can be cut open and flattened to protect the garage
or shop floor.
Whenever working over a painted surface, such as when leaning over
a fender to service something under the hood, always cover it with
an old blanket or bedspread to protect the finish. Vinyl covered pads,
made especially for this purpose, are available at auto parts stores.
The Motor Manual Guy
Booster battery (jump) starting
Certain precautions must be observed when using a booster battery
to start a vehicle.
a) Before connecting the booster battery, make sure the ignition
switch is in the Off position.
b) Turn off the lights, heater and other electrical loads.
c) Your eyes should be shielded. Safety goggles are a good idea.
d) Make sure the booster battery is the same voltage as the dead
one in the vehicle.
e) The t w o vehicles MUST NOT TOUCH each other!
f) Make sure the transmission is in Neutral (manual) or Park
(automatic).
g) If the booster battery is not a maintenance-free type, remove the
vent caps and lay a cloth over the vent holes.
Connect the red jumper cable to the positive (+) terminals of each
battery.
Connect one end of the black jumper cable to the negative H terminal of the booster battery. The other end of this cable should be connected to a good ground on the vehicle to be started, such as a bolt
or bracket on the engine block (see illustration). Use caution to ensure
that the cable will not come into contact with the fan, drivebelts or
other moving parts of the engine.
Start the engine using the booster battery, then, with the engine
running at idle speed, disconnect the jumper cables in the reverse order
of connection.
Make the booster battery cable connections in the
numerical order shown (note that the negative cable of the
booster battery is NOT attached to the negative terminal
of the dead battery)
Jacking and towing
Jacking
in Park (automatic) or Reverse (manual). If a tire is being changed,
loosen the lug nuts one-half turn and leave them in place until the wheel
is raised off the ground.
Place the jack under the vehicle suspension in the indicated position
(see illustration). Operate the jack with a slow, smooth motion until
the wheel is raised off the ground. Remove the lug nuts, pull off the
wheel, install the spare and thread the lug nuts back on with the bev-
The jack supplied with the vehicle should only be used for raising
the vehicle when changing a tire or placing jackstands under the frame.
Warning: Never work under the vehicle or start the engine while this
jack is being used as the only means of support.
The vehicle should be on level ground with the hazard flashers on,
the wheels blocked, the parking brake applied and the transmission
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Jacking points and procedure
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Place the transmission in Park (automatic) or Reverse (manual)
Turn on the hazard flashers
Apply the parking brake
Block the wheel diagonally opposite the one being changed
Use the jack to raise the vehicle
6 Rear jacking point
7 Front jacking point
The Motor Manual Guy
0-18
Jacking and towing
elled sides facing in. Tighten them snugly, but wait until the vehicle
is lowered to tighten them completely. Note that some spare tires are
designed for temporary use only - don't exceed the recommended
speed, mileage or other restrictions accompanying the spare.
Lower the vehicle, remove the jack and tighten the nuts (if loosened
or removed) in a criss-cross pattern.
To wing
As a general rule, vehicles can be towed with all four wheels on the
ground, provided that the driveshaft(s) are removed (see Chapter 8).
Equipment specifically designed for towing should be used and should
be attached to the main structural members of the vehicle,
not the bumper or brackets. Tow hooks are attached t o the frame at
both ends of the vehicle. However, they are for emergency use only
and should not be used for highway towing. Stand clear of vehicles
when using the tow hooks - tow straps and chains may break, causing
serious injury.
Safety is a major consideration when towing and all applicable state
and local laws must be obeyed. A safety chain must be used for all
towing (in addition to the t o w bar).
While towing, the parking brake should be released and the transmission and (if equipped) transfer case must be in Neutral. The steering
must be unlocked (ignition switch in the Off position). Remember that
power steering and power brakes will not work with the engine off.
The Motor Manual Guy
Automotive chemicals and lubricants
A number of automotive chemicals and lubricants are available for
use during vehicle maintenance and repair. They include a wide variety
of products ranging from cleaning solvents and degreasers to lubricants
and protective sprays for rubber, plastic and vinyl.
Cleaners
Carburetor cleaner and choke cleaner is a strong solvent for gum,
varnish and carbon. Most carburetor cleaners leave a dry-type lubricant
film which will not harden or gum up. Because of this film it is not
recommended for use on electrical components.
Brake system cleaner is used t o remove grease and brake fluid from
the brake system where clean surfaces are absolutely necessary. It
leaves no residue and often eliminates brake squeal caused by
contaminants.
Electrical cleaner removes oxidation, corrosion and carbon deposits
from electrical contacts, restoring full current flow. It can also be used
to clean spark plugs, carburetor jets, voltage regulators and other parts
where an oil-free surface is desired.
Demoisturants remove water and moisture from electrical components such as alternators, voltage regulators, electrical connectors
and fuse blocks. It is non-conductive, non-corrosive and non-flammable.
Degreasers are heavy-duty solvents used to remove grease from the
outside of the engine and from chassis components. They can be
sprayed or brushed on, and, depending on the type, are rinsed off either
with water or solvent.
Lubricants
Motor oil is the lubricant formulated for use in engines. It normally
contains a wide variety of additives to prevent corrosion and reduce
foaming and wear. Motor oil comes in various weights (viscosity
ratings) from 5 t o 80. The recommended weight of the oil depends
on the season, temperature and the demands on the engine. Light oil
is used in cold climates and under light load conditions. Heavy oil is
used in hot climates and where high loads are encountered. Multiviscosity oils are designed to have characteristics of both light and
heavy oils and are available in a number of weights from 5W-20 to
20W-50.
Gear oil is designed to be used in differentials, manual transaxles
and other areas where high-temperature lubrication is required.
Chassis and wheel bearing grease is a heavy grease used where
increased loads and friction are encountered, such as for wheel bearings,
balljoints, tie rod ends and universal joints.
High temperature wheel bearing grease is designed to withstand the
extreme temperatures encountered by wheel bearings in disc brake
equipped vehicles. It usually contains molybdenun disulfide (moly),
which is a dry-type lubricant.
White grease is a heavy grease for metal to metal applications where
water is a problem. White grease stays soft under both low and high
temperatures (usually from -100°F t o + 190 °F), and will not wash
off or dilute in the presence of water.
Assembly lube is a special extreme pressure lubricant, usually containing moly, used to lubricate high-load parts such as main and rod
bearings and cam lobes for initial start-up of a new engine. The
assembly lube lubricates the parts without being squeezed out or
washed away until the engine oiling system begins to function.
Siliconelubricants are used to protect rubber, plastic, vinyl and nylon
parts.
Graphite lubricants are used where oils cannot be used due to contamination problems, such as in locks. The dry graphite will lubricate
metal parts while remaining uncontaminated by dirt, water, oil or acids.
It is electrically conductive and will not foul electrical contacts in locks
such as the ignition switch.
Moly penetrants loosen and lubricate frozen, rusted and corroded
fasteners and prevent future rusting or freezing.
Heat-sink grease is a special electrically non-conductive grease that
is used for mounting HEI ignition modules where it is essential that
heat be transferred away from the module.
Sealants
RTVsealant is one of the most widely used gasket compounds. Made
from silicone, RTV is air curing, it seals, bonds, waterproofs, fills surface
irregularities, remains flexible, doesn't shrink, is relatively easy to
remove, and is used as a supplementary sealer with almost all low and
medium temperature gaskets.
Anaerobic sealant is much like RTV in that it can be used either to
seal gaskets or to form gaskets by itself. It remains flexible, is solvent
resistant and fills surface imperfections. The difference between an
anaerobic sealant and an RTV-type sealant is in the curing. RTV cures
when exposed to air, while an anaerobic sealant cures only in the
absence of air. This means that an anaerobic sealant cures only after
the assembly of parts, sealing them together.
Threadandpipe sealant is used for sealing hydraulic and pneumatic
fittings and vacuum lines. It is usually made from a teflon compound,
and comes in a spray, a paint-on liquid and as a wrap-around tape.
Chemicals
Anti-seize compound prevents seizing, galling, cold welding, rust and
corrosion in fasteners. High temperature anti-seize, usually made with
copper and graphite lubricants, is used for exhaust system and manifold
bolts.
Anaerobic locking compounds are used to keep fasteners from vibrating or working loose, and cure only after installation, in the absence
of air. Medium strength locking compound is used for small nuts, bolts
and screws that you expect to be removing later. High strength locking
compound is for large nuts, bolts and studs which you don't intend
to be removing on a regular basis.
Oil additives range from viscosity index improvers to chemical
treatments that claim to reduce internal engine friction. It should be
noted that most oil manufacturers caution against using additives with
their oils.
Gas additives perform several functions, depending on their chemical
makeup. They usually contain solvents that help dissolve gum and
varnish that build up on carburetor and intake parts. They also serve
to break down carbon deposits that form on the inside surfaces of the
combustion chambers. Some additives contain upper cylinder lubricants
for valves and piston rings, and others chemicals to remove condensation from the gas tank.
Miscellaneous
Brake fluid is specially formulated hydraulic fluid that can withstand
the heat and pressure encountered in brake systems. Care must be
taken that this fluid does not come in contact with painted surfaces
or plastics. An opened container should always be resealed to prevent
contamination by water or dirt.
Weatherstrip adhesive is used to bond weatherstripping around
doors, windows and trunk lids. It is sometimes used to attach trim
pieces.
Undercoating is a petroleum-based tar-like substance that is designed
to protect metal surfaces on the underside of the vehicle from corrosion.
It also acts as a sound-deadening agent by insulating the bottom of
the vehicle.
Waxes andpolishes are used to help protect painted and plated surfaces from the weather. Different types of paint may require the use
of different types of wax and polish. Some polishes utilize a chemical
or abrasive cleaner to help remove the top layer of oxidized (dull) paint
on older vehicles. In recent years many non-wax polishes that contain
a wide variety of chemicals such as polymers and silicones have been
introduced. These non-wax polishes are usually easier t o apply and
last longer than conventional waxes and polishes.
The Motor Manual Guy
Safety first!
Regardless of h o w enthusiastic you may be about getting on with
the job at hand, take the time t o ensure that your safety is not jeopardized. A moment's lack of attention can result in an accident, as can
failure t o observe certain simple safety precautions. The possibility o f
an accident will always exist, and the following points should not be
considered a comprehensive list of all dangers. Rather, they are intended t o make you aware of the risks and t o encourage a safety conscious approach t o all work you carry out on your vehicle.
Essential D0s and DON'Ts
DON'T rely on a jack when working under the vehicle. Always use approved jackstands t o support the weight of the vehicle and place them
under the recommended lift or support points.
DON'T attempt to loosen extremely tight fasteners (i.e. wheel lug nuts)
i t may fall.
while the vehicle is on a jack
DON'T start the engine without first making sure that the transmission
is in Neutral (or Park where applicable) and the parking brake is set.
DON'T remove the radiator cap from a hot cooling system - let it cool
or cover it w i t h a cloth and release the pressure gradually.
DON'T attempt t o drain the engine oil until you are sure it has cooled
to the point that it will not burn you.
DON'T touch any part of the engine or exhaust system until it has
cooled sufficiently t o avoid burns.
DON'T siphon toxic liquids such as gasoline, antifreeze and brake fluid
by mouth, or allow them t o remain on your skin.
DON'T inhale brake lining dust
it is potentially hazardous (see
Asbestos below)
DON'T allow spilled oil or grease t o remain on the floor
wipe it u p
before someone slips on it.
DON'T use loose fitting wrenches or other tools which may slip and
cause injury.
DON'T push on wrenches when loosening or tightening nuts or bolts.
Always try t o pull the wrench toward you. If the situation calls for
pushing the wrench away, push with an open hand t o avoid scraped
knuckles if the wrench should slip.
DON'T attempt t o lift a heavy component alone
get someone t o
help you.
DON'T rush or take unsafe shortcuts t o finish a job.
DON'T allow children or animals in or around the vehicle while you
are working on it.
DO wear eye protection when using power tools such as a drill, sander,
bench grinder, etc. and when working under a vehicle.
DO keep loose clothing and long hair well out of the way of moving
parts.
DO make sure that any hoist used has a safe working load rating
adequate for the job.
DO get someone t o check on you periodically when working alone on
a vehicle.
DO carry out work in a logical sequence and make sure that everything
is correctly assembled and tightened.
DO keep chemicals and fluids tightly capped and out of the reach of
children and pets.
DO remember that your vehicle's safety affects that of yourself and
others. If in doubt on any point, get professional advice.
Fire
Remember at all times that gasoline is highly flammable. Never smoke
or have any kind of open flame around when working on a vehicle.
But the risk does not end there. A spark caused by an electrical short
circuit, by t w o metal surfaces contacting each other, or even by static
electricity built u p in your body under certain conditions, can ignite
gasoline vapors, which in a confined space are highly explosive. Do
not, under any circumstances, use gasoline for cleaning parts. Use an
approved safety solvent.
Always disconnect the battery ground H cable at the battery before
working on any part of the fuel system or electrical system. Never risk
spilling fuel on a hot engine or exhaust component.
It is strongly recommended that a fire extinguisher suitable for use
on fuel and electrical fires be kept handy in the garage or workshop
at all times. Never try t o extinguish a fuel or electrical fire w i t h water.
Fumes
Certain fumes are highly toxic and can quickly cause unconsciousness and even death if inhaled to any extent. Gasoline vapor falls into
this category, as do the vapors from some cleaning solvents. Any draining or pouring of such volatile fluids should be done in a well ventilated
area.
When using cleaning fluids and solvents, read the instructions on
the container carefully. Never use materials from unmarked containers.
Never run the engine in an enclosed space, such as a garage. Exhaust
fumes contain carbon monoxide, which is extremely poisonous. If you
need t o run the engine, always d o so in the open air, or at least have
the rear of the vehicle outside the work area.
If you are fortunate enough to have the use of an inspection pit, never
drain or pour gasoline and never run the engine while the vehicle is
over the pit. The fumes, being heavier than air, will concentrate in the
pit w i t h possibly lethal results.
The battery
Never create a spark or allow a bare light bulb near the battery. The
battery normally gives off a certain amount of hydrogen gas, which
is highly explosive.
Always disconnect the battery ground H cable at the battery before
working on the fuel or electrical systems.
If possible, loosen the filler caps or cover when charging the battery
from an external source. Do not charge at an excessive rate or the battery may burst.
Take care when adding water and when carrying a battery. The electrolyte, even when diluted, is very corrosive and should not be allowed
t o contact clothing or skin.
Always wear eye protection when cleaning the battery to prevent
the caustic deposits from entering your eyes.
Household current
When using an electric power tool, inspection light, etc., which
operates on household current, always make sure that the tool is correctly connected t o its plug and that, where necessary, it is properly
grounded. Do not use such items in damp conditions and, again, do
n o t create a spark or apply excessive heat in the vicinity of fuel or fuel
vapor.
Asbestos
Secondary ignition s ystem voltage
Certain friction, insulating, sealing, and other products
such as
brake linings, brake bands, clutch linings, torque converters, gaskets,
etc.
contain asbestos. Extreme care must be taken to avoidinhalation
of dust from such products since i t is hazardous to health. If in doubt,
assume that they do contain asbestos.
A severe electric shock can result from touching certain parts of the
ignition system (such as the spark plug wires) when the engine is running or being cranked, particularly if components are damp or the insulation is defective. In the case of an electronic ignition system, the secondary system voltage is much higher and could prove fatal.
The Motor Manual Guy
Conversion factors
Length (distance)
X 25.4 = Millimetres (mm)
X 0.305 = Metres (m)
X 1.609 = Kilometres (km)
= Inches (in)
= Feet (ft)
X
X
X
0.0394
3.281
0.621
X
X
X
X
X
X
X
X
0.061
1.76
0.88
0.833
1.057
0.22
0.833
0.264
= lrnperial pints (Imp pt)
= lmperial quarts (Irnp qt)
= lmperial quarts (Imp qt)
= US quarts (US qt)
= lmperial gallons (Imp gal)
= lmperial gallons (Irnp gal)
= US gallons (US gal)
X 28.35 = Grams (g)
X 0.454 = Kilograms (kg)
X
X
0.035
2.205
= Ounces (oz)
= Pounds (lb)
X 0.278 = Newtons (N)
X 4.448 = Newtons (N)
X
0.1
= Kilograms-force (kgf; kg)
X
X
X
3.6
0.225
9.81
= Ounces-force (ozf; oz)
= Pounds-force (lbf; lb)
= Newtons (N)
X
14.223
inch
X 0.070 = Kilograms-force per square
centimetre (kgf/cm 2 ; kg/cm2)
X 0.068 =Atmospheres (atm)
X
14.696
inch
X 0.069 = Bars
X
14.5
inch
X 6.895 = Kilopascals (kPa)
X
0.145
X
X
98.1
X
0.868
= Pounds-force inches
X
8.85
= Pounds-force inches
X
12
= Pounds-force inches
X
7.233
= Pounds-force feet (lbf ft; lb ft)
X
X
0.738
9.804
= Pounds-force feet (lbf ft; lb ft)
X
0.0013
Inches (in)
Feet (ft)
Miles
= Miles
Volume (capacity)
Cubic inches (cu in; in 3)
lmperial pints (Imp pt)
lmperial quarts (Irnp qt)
lmperial quarts (Imp qt)
US quarts (US qt)
lrnperial gallons (Imp gal)
lrnperial gallons (Imp gal)
US gallons (US gal)
X
X
X
X
X
X
X
X
16.387
Cubic centimetres (cc; cm 3 )
0.568 = Litres (I)
1.137 = Litres (I)
1.201
US quarts (US qt)
0.946 = Litres (I)
4.546 = Litres (l)
1.201 = US gallons (US gal)
3.785 = Litres (I)
Cubic inches (cu in; in3)
Mass (weight)
Ounces (oz)
Pounds (lb)
Force
Ounces-force (ozf; oz)
Pounds-force (lbf; lb)
Newtons (N)
Pressure
Pounds-force per square
(psi: lbf/in 2 ; lb/in 2 )
Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
Kilopascals (kPa)
inch
0.01
= Kilograms-force per square
centimetre (kgf/cm2; kg/cm 2 )
Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
= Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
= Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
= Pounds-force per square
(psi; lbf/in 2 ; lb/in 2 )
= Kilopascals (kPa)
inch
inch
inch
inch
Torque (moment of force)
Pounds-force
(lbf in; lb in)
Pounds-force
(lbf in; lb in)
Pounds-force
(lbf in: lb in)
Pounds-force
inches
inches
X 1.1 52 = Kilograms-force centimetre
(kgf cm; kg cm)
X 0.1 13 = Newton metres (Nm)
inches
X
feet (lbf ft; lb ft)
X 0.1 38 = Kilograms-force metres
(kgf m; kg m)
X 1.356 = Newton metres (Nm)
X 0.102 = Kilograms-force metres
(kgf m; kg m)
(lbf in; lb in)
(lbf in; lb in)
0.083 = Pounds-force feet (lbf ft; lb ft)
(lbf in; lb in)
Pounds-force feet (lbf ft; lb ft)
Newton metres (Nm)
Newton metres (Nm)
Power
Horsepower (hp)
X
745.7 =Watts (W)
X
1.609 = Kilornetres per hour (km/hr; kph) X
Horsepower (hp)
Velocity (speed)
Miles per hour (miles/hr; mph)
0.621
= Miles per hour (miles/hr; mph)
2.825
2.352
= Miles per gallon, lrnperial (mpg)
= Miles per gallon, US (mpg)
Fuel consumption*
Miles per gallon, lrnperial (mpg)
Miles per gallon, US (mpg)
X 0.354 = Kilometres per litre (km/I)
X 0.425 = Kilometres per litre (km/I)
Temperature
Degrees Fahrenheit
= (OC x 1.8)
+
32
X
X
Degrees Celsius (Degrees Centigrade; oc)
*It is comrrion practice to convert from miles per gallon (mpg) to litres/TOO kilometres (l/100km),
235
where mpg (Imperial) x 1/100 km = 282 and mpg (US) x 1/100 km
= (OF
- 32) x 0.56
The Motor Manual Guy
Troubleshooting
Contents
Symptom
Section
Driveshaft
Engine and performance
Alternator light fails to come on when key is turned on
Alternator light stays on
Battery will not hold a charge
Engine backfires
Engine diesels (continues to run) after being turned off
Engine hard to start when cold
Engine hard to start when hot
Engine lacks power
Engine 'lopes' while idling or idles erratically
Engine misses at idle speed
Engine misses throughout driving speed range
Engine rotates but will not start
Engine stalls
Engine starts but stops immediately
Engine surges while holding accelerator steady
Engine will not rotate when attempting t o start
Excessive fuel consumption
Excessively high idle speed
Excessive oil consumption
Fuel odor
Hesitation or stumble during acceleration
Low oil pressure
Miscellaneous engine noises
Pinging or knocking engine sounds when engine
is under load . . . . . . . . . . . . . . . . . . . . . . ...........
. . . . . . . . . . . . .
Starter motor noisy or engages roughly
Starter motor operates without turning engine
13
12
11
18
21
4
5
17
8
9
14
2
16
7
19
1
24
10
23
25
15
22
26
20
6
3
Cooling system
Abnormal coolant loss
Corrosion
External coolant leakage
Internal coolant leakage
Overcooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overheatinn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Poor coolant circulation
.
.
31
33
29
30
28
27
32
Clutch
Clutch pedal stays on floor when disengaged
Clutch slips (engine speed increases
with no increase in vehicle speed)
Fails to release (pedal pressed to the floor.shift lever
does not move freely in and out of Reverse)
Grabbing (chattering) as clutch is engaged
Squeal or rumble with clutch disengaged (pedal depressed)
Squeal or rumble with clutch engaged (pedal released)
39
35
..
34
36
38
37
Manual transmission
Difficulty engaging gears . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise occurs while shifting gears . . . . . . . . . . . . . . . . . . . . .
Noisy in all gears
Noisy in Neutral with engine running
Noisy in one particular gear
Oil leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Slips out of gear
45
46
41
40
42
44
43
Automatic transmission
Engine will start in gears other than Park or Neutral
Fluid leakage
General shift mechanism problems
Transmission slips. shifts rough. is noisy or has
no drive in forward or Reverse gears
Transmission will not downshift with the
accelerator pedal pressed to the floor
Section
Symptom
50
47
48
51
49
Knock or clunk when transmission is under initial
load (just after transmission is put into gear) . . . . . . . . . . .
Leaks at front of driveshaft . . . . . . . . . . . . . . . . . . . . . . . . . .
Metallic grating sound consistent with vehicle speed . . . . . . .
Scraping noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vibration
Whining or whistling noise . . . . . . . . . . . . . . . . . . . . . . . . . .
53
52
54
56
55
57
Rear axle and differential
Knocking sound when starting or shifting gears . . . . . . . . . . .
Noise.same when in drive as when vehicle is coasting . . .
Noise when turning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
59
58
60
62
61
Transfer case (4WD models)
Difficult shifting
Gear jumping out of mesh
Noise . . . . . . . . . . . . . . . .
..........................
..........................
64
63
65
Brakes
Brake pedal feels spongy when depressed
Brake pedal pulsates during brake application
Brakes drag (indicated by sluggish engine performance
or wheels being very hot after driving) . . . . . . . . . . . . . . . .
Excessive brake pedal travel
Excessive effort required t o stop vehicle
Noise (high-pitched squeal)
Pedal travels to the floor with little resistance
Rear brakes lock up under heavy brake application
Rear brakes lock up under light brake application
Vehicle pulls to one side during braking
69
72
73
68
70
67
71
75
74
66
Suspension and steering
Excessively stiff steering
Excessive pitching and/or rolling around
corners or during braking
Excessive play in steering
Excessive tire wear (not specific to one area)
Excessive tire wear on inside edge
Excessive tire wear on outside edge
Lack of power assistance . . . . . . . . . . . . . . . . . . . . . . . . . . .
Miscellaneous noises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noisy power steering pump . . . . . . . . . . . . . . . . . . . . . . . . .
Shimmy. shake or vibration
Steering effort not the same in both
directions (power system) . . . . . . . . . . . . . . . . . . . . . . . . .
Steering wheel fails to return to straight-ahead position
Tire tread worn in one place
Vehicle pulls to one side
Wandering or general instability
80
78
81
87
89
88
82
86
85
77
84
83
90
76
79
This Section provides an easy reference guide to the more common
problems that may occur during the operation of your vehicle. Various
symptoms and their probable causes are grouped under headings
denoting components or systems. such as Engine. Cooling system.
etc . They also refer t o the Chapter and/or Section that deals with the
problem.
Remember that successful troubleshooting isn't a mysterious 'black
art' practiced only by professional mechanics. it's simply the result
of knowledge combined with an intelligent. systematic approach to
a problem. Always use a process of elimination starting with' the
simplest solution and working through to the most complex - and
The Motor Manual Guy
Troubleshooting
never overlook the obvious. Anyone can run the gas tank dry or leave
the lights on overnight, so don't assume that you're exempt from such
oversights.
Finally, always establish a clear idea why a problem has occurred
and take steps to ensure that it doesn't happen again. If the electrical
system fails because of a poor connection, check all other connections
in the system to make sure they don't fail as well. If a particular fuse
continues t o blow, find out why - don't just go on replacing fuses.
Remember, failure of a small component can often be indicative of
potential failure or incorrect functioning of a more important component
or system.
4
0-23
Engine hard t o start when cold
1 Battery discharged or low. Check as described in Chapter 1.
2 Fuel not reaching the carburetor or fuel injectors. Check the fuel
filter, lines and fuel pump (Chapters 1 and 4).
3 Choke inoperative (Chapters 1 and 4).
4 Defective spark plugs (Chapter 1 ).
5 On 1986 Cherokee Wagoneer and Comanche models with fourcylinder TBI-equipped engines, a Jeep service bulletin no. INJ TBI/G-9-8
has been issued concerning this problem. Take the vehicle to a dealer
and inform him of the problem.
Engine and performance
1
Engine w i l l n o t rotate when attempting t o start
1 Battery terminal connections loose or corroded. Check the cable
terminals at the battery; tighten cable clamp and/or clean off corrosion as necessary (see Chapter 1).
2 Battery discharged or faulty. If the cable ends are clean and tight
on the battery posts, turn the key to the On position and switch on the
headlights or windshield wipers. If they won't run, the battery is discharged.
3 Automatic transmission not engaged in park (P) or Neutral (N).
4 Broken, loose or disconnected wires in the starting circuit. Inspect all wires and connectors at the battery, starter solenoid and ignition switch (on steering column).
5 Starter motor pinion jammed in flywheel ring gear. If manual
transmission, place transmission in gear and rock the vehicle t o
manually turn the engine. Remove starter (Chapter 5) and inspect
pinion and flywheel (Chapter 2) at earliest convenience.
6 Starter solenoid faulty (Chapter 5).
7
Starter motor faulty (Chapter 5).
8 lgnition switch faulty (Chapter 12).
9 Engine seized. Try to turn the crankshaft with a large socket and
breaker bar on the pulley bolt.
2 Engine rotates but will not start
1 Fuel tank empty.
2 Battery discharged (engine rotates slowly). Check the operation
of electrical components as described in previous Section.
3 Battery terminal connections loose or corroded. See previous
Section.
4 Fuel not reaching carburetor or fuel injector. Check for clogged
fuel filter or lines and defective fuel pump. Also make sure the tank
vent lines aren't clogged (Chapter 4).
5 Choke not operating properly (Chapter 1 ).
6 Faulty distributor components. Check the cap and rotor (Chapter 1 ).
7 Low cylinder compression. Check as described in Chapter 2.
8 Valve clearances not properly adjusted (V6 engine) (Chapter 2B).
9 Water in fuel. Drain tank and fill with new fuel.
10 Defective ignition coil (Chapter 5).
1 1 Dirty or clogged carburetor jets or fuel injector. Carburetor out of
adjustment. Check the float level (Chapter 4).
12 Wet or damaged ignition components (Chapters 1 and 5).
1 3 Worn, faulty or incorrectly gapped spark plugs (Chapter 1 ).
1 4 Broken, loose or disconnected wires in the starting circuit (see
previous Section).
15 Loose distributor (changing ignition timing). Turn the distributor
body as necessary to start the engine, then adjust the ignition timing
as soon as possible (Chapter 1 ).
1 6 Broken, loose or disconnected wires at the ignition coil or faulty
coil (Chapter 5).
17 Timing chain failure or wear affecting valve timing (Chapter 2).
5
Engine hard t o start when hot
1
2
for
3
4
5
6
Air filter dirty (Chapter 1 ).
Fuel not reaching carburetor or fuel injectors (see Section 4). Check
a vapor lock situation, brought about by clogged fuel tank vent lines.
Bad engine ground connection.
Choke sticking (Chapter 1).
Defective pick-up coil in distributor (Chapter 5).
Float level too high (Chapter 4).
6
Starter motor noisy or engages roughly
1 Pinion or flywheel/driveplate teeth worn or broken. Remove the
inspection cover on the left side of the engine and inspect.
2 Starter motor mounting bolts loose or missing.
7
Engine starts but stops immediately
1 Loose or damaged wire harness connections at distributor, coil or
alternator.
2 Intake manifold vacuum leaks. Make sure all mounting boltslnuts
are tight and all vacuum hoses connected to the manifold are attached
properly and in good condition.
3 Insufficient fuel flow (see Chapter 4).
8
Engine 'lopes' while idling or idles erratically
1 Vacuum leaks. Check mounting bolts at the intake manifold for
tightness. Make sure that all vacuum hoses are connected and in good
condition. Use a stethescope or a length of fuel hose held against your
ear t o listen for vacuum leaks while the engine is running. A hissing
sound will be heard. A soapy water solution will also detect leaks.
Check the intake manifold gasket surfaces.
2 Leaking EGR valve or plugged PCV valve (see Chapters 1 and 6).
3 Air filter clogged (Chapter 1 ).
4 Fuel pump not delivering sufficient fuel (Chapter 4).
5 Leaking head gasket. Perform a cylinder compression check
(Chapter 2).
6 Timing chain worn (Chapter 2).
7 Camshaft lobes worn (Chapter 2).
8 Valve clearance out of adjustment (V6 engine) (Chapter 2B). Valves
burned or otherwise leaking (Chapter 2).
9 Ignition timing out of adjustment (Chapter 1 ).
1 0 lgnition system not operating properly (Chapters 1 and 5).
11 Thermostatic air cleaner not operating properly (Chapter 1 ).
1 2 Choke not operating properly (Chapters 1 and 4).
13 Dirty or clogged injectors. Carburetor dirty, clogged or out of adjustment. Check the float level (Chapter 4).
1 4 Idle speed out of adjustment (Chapter 1 ).
3 Starter motor operates without turning engine
9 Engine misses at idle speed
1 Starter pinion sticking. Remove the starter (Chapter 5) and inspect.
2 Starter pinion or flywheelldriveplate teeth worn or broken. Remove
the inspection cover and inspect.
1
2
Spark plugs faulty or not gapped properly (Chapter 1).
Faulty spark plug wires (Chapter 1 ).
The Motor Manual Guy
0-24
Troubleshooting
3 Wet or damaged distributor components (Chapter 1 ).
4 Short circuits in ignition, coil or spark plug wires.
5 Sticking or faulty emissions systems (see Chapter 6).
6 Clogged fuel filter and/or foreign matter in fuel. Remove the fuel
filter (Chapter 1) and inspect.
7 Vacuum leaks at intake manifold or hose connections. Check as
described in Section 8.
8 lncorrect idle speed (Chapter 1) or idle mixture (Chapter 4).
9 lncorrect ignition timing (Chapter 1 ).
1 0 Low or uneven cylinder compression. Check as described in
Chapter 2.
1 1 Choke not operating properly (Chapter 1 ).
12 Clogged or dirty fuel injectors (Chapter 4).
10
1
2
3
4
Excessively high idle speed
Sticking throttle linkage (Chapter 4).
Choke opened excessively at idle (Chapter 4).
ldle speed incorrectly adjusted (Chapter 1 ).
Valve clearances incorrectly adjusted (V6 engine) (Chapter 2B).
2 lgnition system not operating properly (Chapter 5).
3 Dirty or clogged carburetor or fuel injector (Chapter 4).
4 Low fuel pressure. Check for proper operation of the fuel pump
and for restrictions in the fuel filter and lines (Chapter 4).
5 Carburetor out of adjustment (Chapter 4).
16 Engine stalls
ldle speed incorrect (Chapter 1).
2 Fuel filter clogged and/or water and impurities in the fuel system
(Chapter 1 ).
3 Choke not operating properly (Chapter 1 ).
4 Damaged or wet distributor cap and wires.
5 Emissions system components faulty (Chapter 6).
6 Faulty or incorrectly gapped spark plugs (Chapter 1 ). Also check
the spark plug wires (Chapter 1 ).
7 Vacuum leak at the carburetor, intake manifold or vacuum hoses.
Check as described in Section 8.
17
11
1
2
3
4
5
6
12
1
2
13
1
2
3
Battery will not hold a charge
Alternator drivebelt defective or not adjusted properly (Chapter 1 ).
Battery cables loose or corroded (Chapter 1).
Alternator not charging properly (Chapter 5).
Loose, broken or faulty wires in the charging circuit (Chapter 5).
Short circuit causing a continuous drain on the battery.
Battery defective internally.
Alternator light stays on
Fault in alternator or charging circuit (Chapter 5).
Alternator drivebelt defective or not properly adjusted (Chapter 1 ).
Alternator light fails to come on when key is turned on
Faulty bulb (Chapter 12).
Defective alternator (Chapter 5).
Fault in the printed circuit, dash wiring or bulb holder (Chapter 12).
Engine lacks power
1 lncorrect ignition timing (Chapter 1 ).
2 Excessive play in distributor shaft. At the same time check for
faulty distributor cap, wires, etc. (Chapter 1).
3 Faulty or incorrectly gapped spark plugs (Chapter 1 ).
4 Air filter dirty (Chapter 1 ).
5 Faulty ignition coil (Chapter 5).
6 Brakes binding (Chapters 1 and 9).
7 Automatic transmission fluid level incorrect, causing slippage
(Chapter 1 ).
8 Clutch slipping (Chapter 8).
9 Fuel filter clogged and/or impurities in the fuel system (Chapters 1 and 4).
10 EGR system not functioning properly (Chapter 6).
11 Use of sub-standard fuel. Fill tank with proper octane fuel.
12 Low or uneven cylinder compression pressures. Check as described i n Chapter 2.
13 Air leak at carburetor or intake manifold (check as described in
Section 8).
14 Dirty or clogged carburetor jets or malfunctioning choke (Chapters 1 and 4).
--
18 Engine backfires
14 Engine misses throughout driving speed range
1 Fuel filter clogged and/or impurities in the fuel system. Check fuel
filter (Chapter 1) or clean system (Chapter 4).
2 Faulty or incorrectly gapped spark plugs (Chapter 1 ).
3 lncorrect ignition timing (Chapter 1 ).
4 Cracked distributor cap, disconnected distributor wires or damaged
distributor components (Chapter 1 ).
5 Defective spark plug wires (Chapter 1 ).
6 Emissions system components faulty (Chapter 6).
7 Low or uneven cylinder compression pressures. Check as described
in Chapter 2.
8 Weak or faulty ignition coil (Chapter 5).
9 Weak or faulty ignition system (Chapter 5).
10 Vacuum leaks at intake manifold or vacuum hoses (see Section 8).
11 Dirty or clogged carburetor or fuel injector (Chapter 4).
12 Leaky EGR valve (Chapter 6).
13 Carburetor out of adjustment (Chapter 4).
1 4 ldle speed out of adjustment (Chapter 1 ).
15 Hesitation or stumble during acceleration
1
lgnition timing incorrect (Chapter 1).
1
2
3
4
5
6
7
8
EGR system not functioning properly (Chapter 6).
lgnition timing incorrect (Chapter 1 ).
Thermostatic air cleaner system not operating properly (Chapter 6).
Vacuum leak (refer to Section 8).
Valve clearances incorrect (V6 engine) (Chapter 2B).
Damaged valve springs or sticking valves (Chapter 2).
Intake air leak (see Section 8).
Carburetor float level out of adjustment (Chapter 4).
19 Engine surges while holding accelerator steady
1
2
Intake air leak (see Section 8).
Fuel pump not working properly (Chapter 4).
20 Pinging or knocking engine sounds when engine is under load
1 lncorrect grade of fuel. Fill tank with fuel of the proper octane rating.
2 lgnition timing incorrect (Chapter 1 ).
3 Carbon build-up in combustion chambers. Remove cylinder head(s)
and clean combustion chambers (Chapter 2).
4 lncorrect spark plugs (Chapter 1 ).
The Motor Manual Guy
Troubleshooting
21
Engine diesels (continues t o run) after being turned off
1
Idle speed too high (Chapter 1).
lgnition timing incorrect (Chapter 1 ).
lncorrect spark plug heat range (Chapter 1).
Intake air leak (see Section 8).
Carbon build-up in combustion chambers. Remove the cylinder
head(s) and clean the combustion chambers (Chapter 2).
6 Valves sticking (Chapter 2).
7 Valve clearance incorrect (V6 engine) (Chapter 2B).
8 EGR system not operating properly (Chapter 6).
9 Fuel shut-off system not operating properly (Chapter 6).
1 0 Check for causes of overheating (Section 27).
2
3
4
5
22 Low oil pressure
1
2
3
4
5
6
lmproper grade of oil.
Oil pump worn or damaged (Chapter 2).
Engine overheating (refer to Section 27).
Clogged oil filter (Chapter 1).
Clogged oil strainer (Chapter 2).
Oil pressure gauge not working properly (Chapter 2).
23 Excessive oil consumption
1
2
3
4
5
6
7
8
9
10
11
12
13
Loose oil drain plug.
Loose bolts or damaged oil pan gasket (Chapter 2).
Loose bolts or damaged front cover gasket (Chapter 2).
Front or rear crankshaft oil seal leaking (Chapter 2).
Loose bolts or damaged rocker arm cover gasket (Chapter 2).
Loose oil filter (Chapter 1 ).
Loose or damaged oil pressure switch (Chapter 2).
Pistons and cylinders excessively worn (Chapter 2).
Piston rings not installed correctly on pistons (Chapter 2).
Worn or damaged piston rings (Chapter 2).
Intake and/or exhaust valve oil seals worn or damaged (Chapter 2).
Worn valve stems.
Worn or damaged valves/guides (Chapter 2).
0-25
worn crankshaft. To pinpoint the trouble spot, remove the spark plug
wire from one plug at a time and crank the engine over. If the noise
stops, the cylinder with the removed plug wire indicates the problem
area. Replace the bearing and/or service or replace the crankshaft
(Chapter 2).
2 A similar (yet slightly higher pitched) noise to the crankshaft knocking described in the previous paragraph, that becomes more rapid as
the engine accelerates, indicates worn or damaged connecting rod bearings (Chapter 2). The procedure for locating the problem cylinder is
the same as described in Paragraph 1.
3 An overlapping metallic noise that increases in intensity as the
engine speed increases, yet diminishes as the engine warms up indicates abnormal piston and cylinder wear (Chapter 2).To locate the
problem cylinder, use the procedure described in Paragraph 1.
4 A rapid clicking noise that becomes faster as the engine accelerates
indicates a worn piston pin or piston pin hole. This sound will happen
each time the piston hits the highest and lowest points in the stroke
(Chapter 2). The procedure for locating the problem piston is described
in Paragraph 1.
5 A metallic clicking noise coming from the water pump indicates
worn or damaged water pump bearings or pump. Replace the water
pump with a new one (Chapter 3).
6 A rapid tapping sound or clicking sound that becomes faster as
the engine speed increases indicates "valve tapping" or improperly
adjusted valve clearances. This can be identified by holding one end
of a section of hose to your ear and placing the other end at different
spots along the rocker arm cover. The point where the sound is loudest
indicates the problem valve. Adjust the valve clearance (V6 engine)
(Chapter 2B). If the problem persists, you likely have a collapsed valve
lifter or other damaged valve train component. Changing the engine
oil and adding a high viscosity oil treatment will sometimes cure a stuck
lifter problem. If the problem still persists, the lifters, pushrods and
rocker arms must be removed for inspection (see Chapter 2).
7 A steady metallic rattling or rapping sound coming from the area
of the timing chain cover indicates a worn, damaged or out-of-adjustment timing chain. Service or replace the chain and related components
(Chapter 2).
Cooling system
27
Overheating
1
2
24 Excessive fuel consumption
1 Dirty or clogged air filter element (Chapter 1 ).
2 lncorrect ignition timing (Chapter 1 ).
3 lncorrect idle speed (Chapter 1 ).
4 Low tire pressure or incorrect tire size (Chapter 11 ).
5 Fuel leakage. Check all connections, lines and components in the
fuel system (Chapter 4).
6 Choke not operating properly (Chapter 1 ).
7 Dirty or clogged carburetor jets or fuel injectors (Chapter 4).
Insufficient coolant in system (Chapter 1 ).
Drivebelt defective or not adjusted properly (Chapter 1 ).
3 Radiator core blocked or radiator grille dirty and restricted (Chapter 3).
4 Thermostat faulty (Chapter 3).
5 Fan not functioning properly (Chapter 3).
6 Radiator cap not maintaining proper pressure. Have cap pressure
tested by gas station or repair shop.
7 lgnition timing incorrect (Chapter 1 ).
8 Defective water pump (Chapter 3).
9 lmproper grade of engine oil.
1 0 lnaccurate temperature gauge (Chapter 12).
28
Overcooling
25 Fuel odor
1
Fuel leakage. Check all connections, lines and components in the
fuel system (Chapter 4).
2 Fuel tank overfilled. Fill only to automatic shut-off.
3 Charcoal canister filter in Evaporative Emissions Control system
clogged (Chapter 1 ).
4 Vapor leaks from Evaporative Emissions Control system lines
(Chapter 6).
26
Miscellaneous engine noises
1 A strong dull noise that becomes more rapid as the engine accelerates indicates worn or damaged crankshaft bearings or an unevenly
1
2
29
Thermostat faulty (Chapter 3).
lnaccurate temperature gauge (Chapter 12).
External coolant leakage
1 Deteriorated or damaged hoses. Loose clamps at hose connections
(Chapter 1 ).
2 Water pump seals defective. If this is the case, water will drip from
the weep hole in the water pump body (Chapter 3).
3 Leakage from radiator core or header tank. This will require the
radiator to be professionally repaired (see Chapter 3 for removal
procedures).
4 Engine drain plugs or water jacket freeze plugs leaking (see
The Motor Manual Guy
0-26
Troubleshooting
Chapters 1 and 2).
5 Leak from coolant temperature switch (Chapter 3).
6 Leak from damaged gaskets or small cracks (Chapter 2).
7 Damaged head gasket. This can be verifed by checking the condition of the engine oil as noted in Section 30.
30 Internal coolant leakage
Note: lnternal coolant leaks can usually be detected b y examining the
oil. Check the dipstick and inside the rocker arm cover for water
deposits and an oil consistency like that o f a milkshake.
1 Leaking cylinder head gasket. Have the system pressure tested
or remove the cylinder head (Chapter 2) and inspect.
2 Cracked cylinder bore or cylinder head. Dismantle engine and inspect (Chapter 2).
3 Loose cylinder head bolts (tighten as described in Chapter 2).
31 Abnormal coolant loss
1
2
Overfilling system (Chapter 1 ).
Coolant boiling away due to overheating (see causes in Section 27).
3 Internal or external leakage (see Sections 29 and 30).
4 Faulty radiator cap, Have the cap pressure tested.
5 Cooling system being pressurized by engine compression. This
could be due to a cracked head or block or leaking head gasket(s).
35 Clutch slips (engine speed increases with no increase
i n vehicle speed)
1 Worn or oil soaked clutch plate.
2 Clutch plate not broken in. It may take 3 0 or 40 normal starts for
a new clutch to seat.
3 Diaphragm spring weak or damaged. Remove clutch cover/pressure
plate assembly and inspect.
4 Flywheel warped (Chapter 2).
5 Debris in master cylinder preventing the piston from returning to
its normal position.
6 Clutch hydraulic line damaged.
36 Grabbing (chattering) as clutch is engaged
1 Oil on clutch plate. Remove and inspect. Repair any leaks.
2 Worn or loose engine or transmission mounts. They may move
slightly when clutch is released, lnspect mounts and bolts.
3 Worn splines on transmission input shaft. Remove clutch components and inspect.
4 Warped pressure plate or flywheel. Remove clutch components
and inspect.
5 Diaphragm spring fatigued. Remove clutch cover/pressure plate
assembly and inspect.
6 Clutch linings hardened or warped.
7 Clutch lining rivets loose.
32 Poor coolant circulation
1 Inoperative water pump. A quick test is to pinch the top radiator
hose closed with your hand while the engine is idling, then release it.
You should feel a surge of coolant if the pump Is working properly
(Chapter 3).
2 Restriction in cooling system. Drain, flush and refill the system
(Chapter 1). If necessary, remove the radiator (Chapter 3)
and have it reverse flushed or professionally cleaned.
3 Loose water pump drivebelt (Chapter 1 ).
4 Thermostat sticking (Chapter 3).
5 lnsufficient coolant (Chapter 1 ).
33 Corrosion
1 Excessive impurities in the water. Soft, clean water is recommended. Distilled or rainwater is satisfactory.
2 lnsuffiecient antifreeze solution (refer to Chapter 1 for the proper
ratio of water to antifreeze).
3 Infrequent flushing and draining of system. Regular flushing of the
cooling system should be carried out at the specified intervals as
described in (Chapter 1 ).
Clutch
37 Squeal or rumble with clutch engagad (pedal released)
1 Improper pedal adjustment. Adjust pedal free play.
2 Release bearing binding on transmission shaft. Remove clutch components and check bearing. Remove any burrs or nicks, clean and
relubricate before reinstallation.
3 Pilot bushing worn or damaged.
4 Clutch rivets loose.
5 Clutch plate cracked.
6 Fatigued clutch plate torsion springs. Replace clutch plate.
38 Squeal or rumble with clutch disengaged (pedal depressed)
1
2
Worn or damaged release bearing.
Worn or broken pressure plate diaphragm fingers.
39 Clutch pedal stays on floor when disengaged
Binding linkage or release bearing. lnspect linkage or remove clutch
components as necessary.
Note: A l l clutch related service information is located i n Chapter 8,
unless otherwise noted.
Manual transmission
34 Fails t o release (pedal pressed t o the floor - shift lever
Note: A l l manual transmission service information is located i n Chapter
7, unless otherwise noted.
does not move freely i n and out of Reverse)
1
2
Clutch contaminated with oil. Remove clutch plate and inspect.
Clutch plate warped, distorted or otherwise damaged.
3 Diaphragm spring fatigued. Remove clutch cover/pressure plate
assembly and inspect.
4 Leakage of fluid from clutch hydraulic system. lnspect master
cylinder, operating cylinder and connecting lines.
5 Air in clutch hydraulic system. Bleed the system.
6 Insufficient pedal stroke. Check and adjust as necessary.
7 Piston seal in operating cylinder deformed or damaged.
8 Lack of grease on pilot bushing.
40 Noisy i n Neutral with engine running
1
2
Input shaft bearing worn.
Damaged main drive gear bearing.
3 lnsufficient transmission oil (Chapter 1 ).
4 Transmission oil in poor condition. Drain and fill with proper grade
oil. Check old oil for water and debris (Chapter 1 ).
5 Noise can be caused by variations in engine torque. Change the
idle speed and see if noise disappears.
The Motor Manual Guy
Troubleshooting
4 1 Noisy i n all gears
1
2
Any of the above causes, and/or:
Worn or damaged output gear bearings or shaft.
4 2 Noisy i n one particular gear
1
2
43
Worn, damaged or chipped gear teeth.
Worn or damaged synchronizer.
Slips out of gear
1 Transmission loose on clutch housing.
2 Stiff shift lever seal.
3 Shift linkage binding.
4 Broken or loose input gear bearing retainer.
5 Dirt between clutch lever and engine housing.
6 Worn linkage.
7 Damaged or worn check balls, fork rod ball grooves or check
springs.
8 Worn mainshaft or countershaft bearings.
9 Loose engine mounts (Chapter 2).
10 Excessive gear end play.
11 Worn synchronizers.
air flow t o the transmission.
2 To pinpoint a leak, first remove all built-up dirt and grime from the
transmission. Degreasing agents and/or steam cleaning will achieve
this. With the underside clean, drive the vehicle at low speeds so the
air flow will not blow the leak far from its source. Raise the vehicle
and determine where the leak is located. Common areas of leakage are:
a) Fluid pan: tighten mounting bolts and/or replace pan gasket as
necessary (Chapter 1 ).
b) Rear extension: tighten bolts and/or replace oil seal as necessary.
c) Filler pipe: replace the rubber oil seal where pipe enters transmission case.
d) Transmission oil lines: tighten fittings where lines enter transmission case and/or replace lines.
e) Vent pipe: transmission overfilled and/or water in fluid (see checking procedures, Chapter 1 ).
fl Speedometer connector: replace the O-ring where speedometer
cable enters transmission case.
48
49
4 5 Difficulty engaging gears
1 Clutch not releasing completely.
2 Loose or damaged shift linkage. Make a thorough inspection,
replacing parts as necessary.
3 Insufficient transmission oil (Chapter 1 ).
4 Transmission oil in poor condition. Drain and fill with proper grade
oil. Check oil for water and debris (Chapter 1 ).
5 Worn or damaged striking rod.
6 Sticking or jamming gears.
46
Noise occurs while shifting gears
1 Check for proper operation of the clutch (Chapter 8).
2 Faulty synchronizer assemblies. Measure baulk ring-to-gear
clearance. Also, check for wear or damage to baulk rings or any parts
of the svnchromesh assemblies.
Automatic transmission
Note: Due to the complexity o f the automatic transmission, it's difficult for the home mechanic to properly diagnose and service. For
problems other than the following, the vehicle should be taken to a
reputable mechanic.
Fluid leakage
1 Automatic transmission fluid is a deep red color, and fluid leaks
should not be confused with engine oil which can easily be blown by
Transmission will not downshift with the accelerator pedal
pressed t o the floor
Chapter 7 deals with adjusting the TV linkage to enable the transmission to downshift properly.
50
Engine will start i n gears other than Park or Neutral
Chapter 7 deals with adjusting the Neutral start switch installed on
automatic transmissions.
51
Transmission slips, shifts rough, is noisy or has no drive in
forward or Reverse gears
1 There are many probable causes for the above problems, but the
home mechanic should concern himself only with one possibility; fluid
level.
2 Before taking the vehicle to a shop, check the fluid level and condition as described in Chapter 1. Add fluid, if necessary, or change
the fluid and filter if needed. If problems persist, have a professional
diagnose the transmission.
Driveshaft
Note: Refer to Chapter 8, unless otherwise specified, for service information.
52
Leaks a t front of driveshaft
Defective transmission rear seal. See Chapter 7 for replacment
procedure. As this is done, check the splined yoke for burrs or roughness that could damage the new seal. Remove burrs with a fine file
or whetstone.
53
47
General shift mechanism problems
Chapter 7 deals with checking and adjusting the shift linkage on
automatic transmissions. Common problems which may be caused by
out of adjustment linkage are:
a) Engine starting in gears other than P (park) or N (Neutral).
b) Indicator pointing to a gear other than the one actually engaged.
c) Vehicle moves with transmission in P (Park) position.
4 4 Oil leaks
1 Excessive amount of lubricant in transmission (see Chapter 1 for
correct checking procedures). Drain lubricant as required.
2 Rear oil seal or speedometer oil seal damaged.
3 To pinpoint a leak, first remove all built-up dirt and grime from the
transmission. Degreasing agents and/or steam cleaning will achieve
this. With the underside clean, drive the vehicle at low speeds so the
air flow will not blow the leak far from its source. Raise the vehicle
and determine where the leak is located.
8-27
Knock or clunk when transmission is under initial load
(just after transmission is p u t into gear)
1 Loose or disconnected rear suspension components. Check all
mounting bolts and bushings (Chapters 7 and 10).
The Motor Manual Guy
0-28
Troubleshooting
2 Loose driveshaft bolts. lnspect all bolts and nuts and tighten them
securely.
3 Worn or damaged universal joint bearings. Replace driveshaft
(Chapter 8).
4 Worn sleeve yoke and mainshaft spline.
54
Metallic grating sound consistent with vehicle speed
Pronounced wear in the universal joint bearings. Replace U-joints
or driveshafts, as necessary.
55
Defective differential.
61
Vibration
See probable causes under Driveshaft. Proceed under the guidelines
listed for the driveshaft. If the problem persists, check the rear wheel
bearings by raising the rear of the vehicle and spinning the wheels by
hand. Listen for evidence of rough (noisy) bearings. Remove and inspect
(Chapter 8).
62
Oil leaks
1 Pinion oil seal damaged (Chapter 8).
2 Axleshaft oil seals damaged (Chapter 8).
3 Differential cover leaking. Tighten mounting bolts or replace the
gasket as required.
4 Loose filler or drain plug on differential (Chapter 1 ).
5 Clogged or damaged breather on differential.
Transfer case (4WD models)
Note: Refer to Chapter 8 for 4 WDsystem service a n d repair information.
63
1
2
3
4
Gear jumping out of mesh
Incorrect control lever free play (Chapter 7C).
Interference between the control lever and the console.
Play or fatigue in the transfer case mounts.
Internal wear or incorrect adjustments.
6 4 Difficult shifting
1
2
Lack of oil.
lnternal wear, damage or incorrect adjustment.
Scraping noise
65
Make sure the dust cover on the sleeve yoke isn't rubbing on the
transmission extension housing.
57
Noise when turning
Vibration
Note: Before blaming the driveshaft, make sure the tires are perfectly
balanced and perform the following test.
1 Install a tachometer inside the vehicle to monitor engine speed as
the vehicle is driven. Drive the vehicle and note the engine speed at
which the vibration (roughness) is most pronounced. Now shift the
transmission to a different gear and bring the engine speed to the same
point.
2 If the vibration occurs at the same engine speed (rpm) regardless
of which gear the transmission is in, the driveshaft is NOT at fault since
the driveshaft speed varies.
3 If the vibration decreases or is eliminated when the transmission
is in a different gear at the same engine speed, refer to the following
probable causes.
4 Bent or dented driveshaft. lnspect and replace as necessary.
5 Undercoating or built-up dirt, etc. on the driveshaft. Clean the shaft
thoroughly.
6 Worn universal joint bearings. Replace the U-joints or driveshaft
as necessary.
7 Driveshaft and/or companion flange out of balance. Check for missing weights on the shaft. Remove driveshaft and reinstall 1 80° from
original position, then recheck. Have the driveshaft balanced if problem
persists.
8 Loose driveshaft mounting bolts/nuts.
9 Defective center bearing, if so equipped.
10 Worn transmission rear bushing (Chapter 7).
56
60
Whining or whistling noise
Defective center bearing, if so equipped
Noise
1 Lack of oil in transfer case.
2 Noise in 4H and 4L, but not in 2H indicates cause is in the front
differential or front axle.
3 Noise in 2H, 4H and 4L indicates cause is in rear differential or
rear axle.
4 Noise in 2H and 4H but not in 4L, or in 4L only, indicates internal
wear or damage in transfer case.
Rear axle and differential
Brakes
Note: For differential servicing information, refer to Chapter 8, unless otherwise specified.
Note: Before assuming a brake problem exists, make sure the tires
are i n g o o d condition a n d inflated properly, the front e n d alignment
is correct a n d the vehicle is n o t loaded with weight i n an unequal
manner. All service procedures for the brakes are included i n Chapter 9, unless otherwise noted.
58
Noise - same when in drive as when vehicle is coasting
1
2
3
4
5
Road noise. No corrective action available.
Tire noise. lnspect tires and check tire pressures (Chapter 1)
Front wheel bearings loose, worn or damaged (Chapter 1 ).
Insufficient differential oil (Chapter 1 ).
Defective differential.
59
Knocking sound when starting or shifting gears
Defective or incorrectly adjusted differential.
66
Vehicle pulls t o one side during braking
1 Defective, damaged or oil contaminated brake pad on one side.
Inspect asdescribed in Chapter 1. Refer to Chapter9 if replacement is
required.
2 Excessive wear of brake pad material or disc on one side. lnspect
and repair as necessary.
3 Loose or disconnected front suspension components. lnspect
and tighten all bolts securely (Chapters 1 and 10).
4 Defectivecaliper assembly. Remove caliper and inspect for stuck
The Motor Manual Guy
Troubleshooting
piston or damage.
5 Brake pad to rotor adjustment needed. lnspect automatic adjusting
mechanism for proper operation.
6 Scored or out of round rotor.
7 Loose caliper mounting bolts.
8 lncorrect wheel bearing adjustment.
67
0-29
2 Caliper not sliding properly due to improper installation or obstructions. Remove and inspect.
3 Rotor not within specifications. Remove the rotor and check for
excessive lateral runout and parallelism. Have the rotors resurfaced
or replace them with new ones. Also make sure that all rotors are the
same thickness.
4 Out of round rear brake drums. Remove the drums and have them
turned or replace them with new ones.
Noise (high-pitched squeal)
1 Front brake pads worn out. This noise comes from the wear sensor
rubbing against the disc. Replace pads with new ones immediately!
2 Glazed or contaminated pads.
3 Dirty or scored rotor.
4 Bent support plate.
68 Excessive brake pedel travel
1 Partial brake system failure. lnspect entire system (Chapter 1 and
correct as required.
2 Insufficient fluid in master cylinder. Check (Chapter 1) and add
fluid
bleed system if necessary.
3 Air in system. Bleed system.
4 Excessive lateral rotor play.
5 Brakes out of adjustment. Check the operation of the automatic
adjusters.
6 Defective proportioning valve. Replace valve and bleed system.
69 Brake pedal feels spongy when depressed
1 Air in brake lines. Bleed the brake system.
2 Deteriorated rubber brake hoses. lnspect all system hoses and lines.
Replace parts as necessary.
3 Master cylinder mounting nuts loose. lnspect master cylinder bolts
(nuts) and tighten them securely.
4 Master cylinder faulty.
5 lncorrect shoe or pad clearance.
6 Defective check valve. Replace valve and bleed system.
7 Clogged reservoir cap vent hole.
8 Deformed rubber brake lines.
9 Soft or swollen caliper seals.
1 0 Poor quality brake fluid. Bleed entire system and fill with new approved fluid.
73 Brakes drag (indicated by sluggish engine performance
or wheels being very hot after driving)
1 Output rod adjustment incorrect at the brake pedal.
2 Obstructed master cylinder compensator. Disassemble master
cylinder and clean.
3 Master cylinder piston seized in bore. Overhaul master cylinder.
4 Caliper assembly in need of overhaul.
5 Brake pads or shoes worn out.
6 Piston cups in master cylinder or caliper assembly deformed. Overhaul master cylinder.
7 Rotor not within specifications (Section 72).
8 Parking brake assembly will not release.
9 Clogged brake lines.
1 0 Wheel bearings out of adjustment (Chapter 1 ).
11 Brake pedal height improperly adjusted.
12 Wheel cylinder needs overhaul.
1 3 Improper shoe to drum clearance. Adjust as necessary.
74 Rear brakes lock up under light brake application
1
2
Tire pressures too high.
Tires excessively worn (Chapter 1 ).
75 Rear brakes lock up under heavy brake application
1 Tire pressures too high.
2 Tires excessively worn (Chapter 1 ).
3 Front brake pads contaminated with oil, mud or water. Clean or
replace the pads.
4 Front brake pads excessively worn.
5 Defective master cylinder or caliper assembly.
Suspension and steering
70 Excessive effort required t o stop vehicle
1
2
Power brake booster not operating properly.
Excessively worn linings or pads. Check and replace if necessary.
3 One or more caliper pistons seized or sticking. lnspect and rebuild
as required.
4 Brake pads or linings contaminated with oil or grease, lnspect and
replace as required.
5 New pads or linings installed and not yet seated. It'll take a while
for the new material t o seat against the rotor or drum.
6 Worn or damaged master cylinder or caliper assemblies. Check particularly for frozen pistons.
7 Also see causes listed under Section 69.
Note: All service procedures for the suspension and steering systems are included in Chapter 10, unless otherwise noted.
76
1
2
3
4
5
6
7
Vehicle pulls t o one side
Tire pressures uneven (Chapter 1 ).
Defective tire (Chapter 1 ).
Excessive wear in suspension or steering components (Chapter 1 ).
Front end alignment incorrect.
Front brakes dragging. lnspect as described in Section 73.
Wheel bearings improperly adjusted (Chapter 1 ).
Wheel lug nuts loose.
71 Pedal travels t o the floor with little resistance
77
Little or no fluid in the master cylinder reservoir caused by leaking
caliper piston(s) or loose, damaged or disconnected brake lines. lnspect
entire system and repair as necessary.
1 Tire or wheel out of balance or out of round. Have them balanced
on the vehicle.
2 Loose, worn or out of adjustment wheel bearings (Chapter 1 ).
3 Shock absorbers and/or suspension components worn or damaged.
Check for worn bushings in the upper and lower links.
4 Wheel lug nuts loose.
5 lncorrect tire pressures.
6 Excessively worn or damaged tire.
7 Loosely mounted steering gear housing.
72 Brake pedal pulsates during brake application
1
Wheel bearings damaged, worn or out of adjustment (Chapter 1 ).
Shimmy, shake or vibration
The Motor Manual Guy
Troubleshooting
0-30
8
9
10
11
Steering gear improperly adjusted.
Loose, worn or damaged steering components.
Damaged idler arm.
Worn balljoint.
4
5
6
7
8
9
Steering column out of alignment.
Worn or damaged balljoint.
Worn or damaged steering linkage.
Improperly lubricated idler arm.
Insufficient oil in steering gear.
Lack of fluid in power steering pump.
78 Excessive pitching and/or rolling around
corners or during braking
1
2
3
Defective shock absorbers. Replace as a set.
Broken or weak leaf springs and/or suspension components.
Worn or damaged stabilizer bar or bushings.
-
84 Steering effort 'not the same i n both directions (power
system)
--
1
2
Leaks in steering gear.
Clogged fluid passage in steering gear.
-
79 Wandering or general instability
85 Noisy power steering pump
1
2
3
4
5
6
7
8
9
Improper tire pressures.
Worn or damaged upper and lower link or tension rod bushings.
lncorrect front end alignment.
Worn or damaged steering linkage or suspension components.
Improperly adjusted steering gear.
Out of balance wheels.
Loose wheel lug nuts.
Worn rear shock absorbers.
Fatigued or damaged rear leaf springs.
80 Excessively stiff steering
--
1
2
3
4
5
Insufficient oil in pump.
Clogged hoses or oil filter in pump.
Loose pulley.
Improperly adjusted drivebelt (Chapter 1 ).
Defective pump.
86 Miscellaneous noises
1
2
lmproper tire pressures.
Insufficiently lubricated balljoint or steering linkage.
3 Loose or worn steering gear, steering linkage or suspension
components.
4 Defective shock absorber.
5 Defective wheel bearing.
6 Worn or damaged suspension bushings.
7 Damaged leaf spring.
8 Loose wheel lug nuts.
9 Worn or damaged rear axleshaft spline.
1 0 Worn or damaged rear shock absorber mounting bushing.
11 lncorrect rear axle end play.
12 See also causes of noises at the rear axle and driveshaft.
1 Lack of lubricant in power steering fluid reservoir, where appropriate (Chapter 1 ).
2 lncorrect tire pressures (Chapter 1 ).
3 Lack of lubrication at balljoints (Chapter 1 ).
4 Front end out of alignment.
5 Steering gear out of adjustment or lacking lubrication.
6 Improperly adjusted wheel bearings.
7 Worn or damaged steering gear.
8 Interference of steering column with turn signal switch.
9 Low tire pressures.
1 0 Worn or damaged balljoints.
11 Worn or damaged steering linkage.
12 See also Section 79.
87 Excessive tire wear (not specific t o one area)
81 Excessive play i n steering
1
2
3
1
2
3
4
5
6
Loose wheel bearings (Chapter 1 ).
Excessive wear in suspension bushings (Chapter 1).
Steering gear improperly adjusted.
lncorrect front end alignment.
Steering gear mounting bolts loose.
Worn steering linkage.
82 Lack of power assistance
4
lncorrect tire pressures.
Tires out of balance. Have them balanced on the vehicle.
Wheels damaged. lnspect and replace as necessary.
Suspension or steering components worn (Chapter 1 ).
88 Excessive tire wear on outside edge
I
2
3
Incorrect tire pressure.
Excessive speed in turns.
Front end alignment incorrect (excessive toe-in)
Steering pump drivebelt faulty or not adjusted properly (Chapter 1 ).
Fluid level low (Chapter 1 ).
3 Hoses or pipes restricting the flow. lnspect and replace parts as
necessary.
4 Air i n power steering system. Bleed system.
5 Defective power steering pump.
3
83 Steering wheel fails to return to straight-ahead position
90 Tire tread worn i n one place
1
2
3
1
2
1
2
lncorrect front end alignment.
Tire pressures low.
Steering gears improperly engaged.
89 Excessive tire wear on inside edge
1
2
3
lncorrect tire pressure.
Front end alignment incorrect (toe-out).
Loose or damaged steering components (Chapter 1 ).
Tires out of balance. Have them balanced on the vehicle.
Damaged or buckled wheel. lnspect and replace if necessary.
Defective tire.
The Motor Manual Guy
Chapter 1-Tune-up and routine maintenance
Contents
Air filter and PCV filter replacement
32
34
Automatic transmission fluid and filter change
Automatic transmission fluid level check.......................................
6
Battery check and maintenance ....................................................
8
Brake check ...................................................................................
20
Carburetor choke check................................................................. 22
23
Carburetor/throttle body mounting nut torque check ....................
Chassis lubrication
13
Cooling system check ....................................................................
9
Cooling system servicing (draining, flushing and refilling)
39
See Chapter 2
Cylinder compression check
Differential lubricant change ..........................................................
36
Differential lubricant level check ....................................................
17
Distributor cap and rotor check and replacement......................... 45
Drivebelt check, adjustment and replacement............................... 26
Engine oil and filter change............................................................
12
Evaporative emissions control system check
41
Exhaust Gas Recirculation (EGR) system check............................ 42
Exhaust system check ................................................................... 15
Fluid level checks ...........................................................................
4
Front wheel bearing check, repack and
,adjustment (2WD models).............................................................
38
Fuel filter replacement....................................................................
31
Fuel system check
21
Idle speed check and adjustment (1984 through
1986 carburetor-equippedmodels)
30
Ignition timing check and adjustment (1984 through
1986 carburetor-equipped models)..............................................
Introduction
Maintenance schedule...................................................................
Manual transmission lubricant change ..........................................
Manual transmission lubricant level check ....................................
Neutral start switch check..............................................................
Oxygen sensor and emission maintenance timer
replacement (1988 and later 49-state models)
Positive Crankcase Ventilation (PCV) valve or Crankcase
Ventilation (CCV) hose check, cleaning and replacement
Power steering fluid level check.....................................................
Seatbelt check ...............................................................................
Spare tire and jack check...............................................................
Spark plug replacement.................................................................
Spark plug wire check and replacement........................................
Suspension and steering check .....................................................
Thermostatic air cleaner check ......................................................
Throttle linkage inspection.............................................................
Tire and tire pressure checks.........................................................
Tire rotation
Transfer case lubricant change (4WD models) ..............................
Transfer case lubricant level check (4WD models) ........................
Tune-up general information..........................................................
Underhood hose check and replacement
Wiper blade inspection and replacement ......................................
33
2
1
35
16
28
46
40
T
27
29
43
44
14
25
24
5
19
37
18
3
10
11
Specification
Recommended lubricants and fluids
Engine oil type .................................................................................
Engine oil viscosity ..........................................................................
Automatic transmission fluid*
AW-4 transmission.....................................................................
727 and 999 transmissions........................................................
Manual transmission lubricant.........................................................
* The fluid type should be indicated on the dipstick
Differential lubricant
Normal use .................................................................................
Trailer towing..............................................................................
Limited slip differential ...............................................................
Transfer case lubricant ....................................................................
Chassis grease ................................................................................
Engine coolant
Brake fluid........................................................................................
Clutch fluid.......................................................................................
Power steering fluid.........................................................................
Manual steering box lubricant .........................................................
Wheel bearing grease (2WD) .......................................................... .
SF, SF/CC, SF/CD or SF/SG
See accompanying chart
Mercon ATF
Dexron II ATF
SAE 75W-90 GL-5 gear lubricant
SAE 75W or SAE 80W-90
GL-5 gear lubricant
SAE 80W GL-5 gear lubricant
Add 2 oz. of Friction Modifier Additive
Dexron II or Mercon automatic
transmission fluid
NLGl No. 2 chassis grease
Mixture of water and ethylene
glycol-base antifreeze
DOT-3 brake fluid
DOT-3 brake fluid
Jeep power steering fluid
or equivalent
SAE 75W-90 GL-5 gear lubricant
NLGl No. 2 moly-base wheel
bearing grease
•c
4 qts
4 qts
6 qts
10 qts
12.5 qts
RECOMMENDED
OILS, SAE
•F
40
100
30
80
20
60
6Q•F
(16•q
20W.S0
20W-40
l0W-40
l0W-30
10
40
0
10
20
30
Capacities
Engine oil (with filter change, approximate)
Four-cylinder engine ..................................................................
V6 engine ...................................................................................
lnline six-cylinder engine............................................................
Cooling system (approximate)
Four-cylinder engine ................................................................
V6 engine and inline six-cylinder engines
Fuel tank
Standard
Optional
Automatic transmission (approximate)
AMBIENT
TEMPERATURE
RANGE
20
0
20
30°F
(-l•q
5W,30
0°F
(-1s•q
u
ENGINE OIL VISCOSITY
For best fuel economy and cold
starting, select the lowest SAE
viscosity grade oil for the expected
temperature range.
13.5 gal
20 gal
4 qts (when draining pan and replacing filter only)
1.
The Motor Manual Guy
Chapter 1 Tune-up and routine maintenance
1-2
Capacities (continued)
Manual transmission (approximate)
4-speed
5-speed
Transfer case (approximate)
Selec-trac...................................................................................
Command-trac
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::·····
7.5 pints
7.2 pints
3.0 pints
2.2 pints
Ignition system
Firing order
Four-cylinder engine
V6 engine ...................................................................................
six-cylinder engine
Spark plug type and gap
Four-cylinder engine
1985 and earlier
Type
lnline
Gao.:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
1986 and later
Type
Gao.::::::::::::::::::::::::::::::::::::::::::::::::::·······························
·······························
V6 engine
Type
.nGeao .:::::::::::::::::::::::::::::::::::::::::::::::::::::::·······························
...............................
lnll six-cylinder engine
1990 and earlier
Type .................................................................................
Gap ..................................................................................
1991 and later
Tvoe
.. ........................ .........................................................
Gap..
Ignition timing
Four-cylinder engine (1984 and 1985 models only)
Below 4000 feet
Above 4000 feet
V6 engine
Automatic transmission........................................................
Manual transmission
California models.............................. ...............................
All others··········································· ...............................
six-cylinder engine............................................................
lnline
1-3-4-2
1-2-3-4-5-6
1-5-3-6-2-4
ORDER
4-CYLINDER ENGINE
Champion RFN14LY
0.035 in
Champion RC12LYC
0.035 in
Champion RV12YC
0.045 in
Champion RC9YC
0.035 in
Champion RC12LYC
0.035 in
12-degrees BTDC
19-degrees BTDC
V6 ENGINE
12-degrees BTDC
0-degrees BTDC
8-degrees BTDC
Not adjustable
General
Engine idle speed (carbureted-models only)
Four-cylinder engine
Automatic transmission (in Drive)
Manual transmission
V6 engine
Automatic transmission (in Drive)
Manual transmission.............................................................
CYLINDER NUMBERS
ENGINE FRONT
®® ©@ ®0
700 rpm
750 rpm
700 ± 50 rpm
700 ± 50 rpm
Drivebelt tension (with special gauge)
Conventional V-belts
New
Used .......
Serpentine belt
New
Used
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
120 to 150 lbs
90 to 115 lbs
··········::::::::::::::::::::::·························································
.........................................................
180 to 200 Ibs
140 to 160 lbs
Brakes
in
in
Brake pad wear limit........................................................................
Brake shoe wear limit ......................................................................
1/8
1/16
Torque specifications
Ft-lbs
10 to 20
20
Differential (axle) fill plug
.........................................................
Engine oil drain plug ........................................................................
Wheel lug nuts .................................................................................
Manual transmission
plug
Manual transmission drain plug.......................................................
Transfer case
plug .............................................................
Automatic transmission oil pan bolts ..............................................
Carburetor mounting nuts ...............................................................
Throttle body mounting nuts ...........................................................
Carburetor-mounted fuel filter nut
Spark plugs
Four-cylinder engine
.........................................................
V6 engine ·························· ..................................................
six-cylinder engine
check/fill
drain/fill
lnline
75
15 to 25
15 to 25
20
10
13 to 19
16
18
27
22
27
INLINE 6-CYLINDER ENGINE
Cylinder location and distributor rotation
The Motor Manual Guy
1
~/
Jeep Cherokee/Comanche/'lo
Maintenance schedule
The following maintenance intervals are based on the assumption
that the vehicle owner will be doing the maintenance or service
work, as opposed to having a dealer service department do the
work. Although the time/mileage intervals are loosely based on factory recommendations, most have been shortened to ensure, for
example, that such items as lubricants and fluids are checked/
changed at intervals that promote maximum engineldriveline service
life. Also, subject to the preference of the individual owner interested
in keeping his or her vehicle in peak condition at all times, and with
the vehicle's ultimate resale in mind, many of the maintenance procedures may be performed more often than recommended in the
following schedule. We encourage such owner initiative.
When the vehicle is new it should be serviced initially by a factory
authorized dealer service department to protect the factory warranty.
In many cases the initial maintenance check is done at no cost to
the owner (check with your dealer service department for more
information).
Every 250 miles or weekly,
whichever comes first
Check
Check
Check
Check
Check
the
the
the
the
the
engine oil level (Section 4)
engine coolant level (Section 4)
windshield washer fluid level (Section 4 )
brake and clutch fluid levels (Section 4)
tires and tire pressures (Section 5)
Every 3000 miles or 3 months,
whichever comes first
All items listed above plus:
Check the automatic transmission fluid
level (Section 6)
Check the power steering fluid level (Section 7)
Check and service the battery (Section 8 )
Check the cooling system (Section 9)
lnspect and replace, if necessary, all underhood
hoses (Section 10)
lnspect and replace, if necessary, the windshield
wiper blades (Section 11)
Every 7500 miles or 12 months,
whichever comes first
All items listed above plus:
Change the engine oil and filter (Section 12)*
Lubricate the chassis components (Section 13)
lnspect the suspension and steering
components (Section 14)
lnspect the exhaust system (Section 15) *
Check the manual transmission lubricant level (Section 16)*
Check the differential lubricant level (Section 17)*
Check the transfer case lubricant level (4WD
models) (Section 18)
Rotate the tires (Section 19)
Check the brakes (Section 20)*
lnspect the fuel system (Section 21)
Check the carburetor choke operation (Section 22)
Check the carburetor/throttle body mounting nut
torque (Section 23)
Check the throttle linkage (Section 24)
Check the thermostatically-controlled air
cleaner (Section 25)
Check the engine drivebelts (Section 26)
Check the seatbelts (Section 27)
Check the starter safety switch (Section 28)
Check the spare tire and jack (Section 29)
1
Every 30,000 miles or 24 months,
whichever comes first
All items listed above plus:
Check and adjust, if necessary, the engine idle
speed (Section 30)
Replace the fuel filter (Section 31)
Replace the air and PCV filters (Section 32)
Check and adjust, if necessary, the ignition timing (Section 33)
Change the automatic transmission fluid (Section 34)**
Change the manual transmission lubricant (Section 35)
Change the differential lubricant (Section 36)
Change the transfer case lubricant
(4WD models) (Section 37)
Check and repack the front wheel bearings
(2WD models) (Section 38)
Service the cooling system (drain, flush and
refill) (Section 39)
lnspect and replace, if necessary, the PCV valve (Section 40)
lnspect the evaporative emissions control system (Section 41)
Check the EGR system (Section 42)
Replace the spark plugs (Section 43)
lnspect the spark plug wires, distributor cap
and rotor (Sections 44 and 45)*
* Replace the wires, cap and rotor at 60,000 miles
Every 82,500 miles or 82 months,
whichever comes first
Replace the oxygen sensor and emissions
timer (49-state models) (Section 46)
This item is affected by "severe" operating conditions as described below. If your vehicle is operated under severe conditions,
perform all maintenance indicated with an asterisk (*) at 3000
mile/3 month intervals. Severe conditions are indicated if you mainly
operate your vehicle under one or more of the following:
Operating in dusty areas
To wing a trailer
Idling for extended periods and/or low speed operation
Operating when outside temperatures remain below freezing and
when most trips are less than four miles
* * If operated under one or more of the following conditions, change
the automatic transmission fluid every 12,000 miles:
In heavy city traffic where the outside temperature regularly
reaches 90 °ᇫF (32°G) or higher
In hilly or mountainous terrain
Frequent trailer pulling
The Motor Manual Guy
,------------------------------------------------1
.i:.
Engine compartment component checking points (inline six-cylinder engine shown)
1 Crankcase Ventilation (CCV}
system hose and fitting
2 Clutch fluid reservoir
3 Brake fluid reservoir
4 Windshield washer reservoir
5 Air cleaner housing
6 Power steering fluid reservoir
7
8
9
10
11
12
13
14
Drivebelt
CCV fresh air hose
Engine oil filler cap
Engine oil dipstick
Radiator hose
Battery
Air conditioner hose
Coolant pressure bottle
JI
The Motor Manual Guy
Typical engine compartment under side components ~WD vehicle shown)
2
3
4
5
Front driveshaft slip joint
grease fitting
Transmission
Engine oil drain plug
Exhaust pipe
Brake hose
6
7
8
9
10
Steering linkage
Steering damper
Front driveaxle
Front disc brake caliper
Front driveshaft
universal joint
------------------------------------------------~I
.
~
I
r
~
The Motor Manual Guy
Typical rear under side vehicle components
1
2
3
4
5
Rear leaf spring
Muffler
Driveshaft
Universal joint
Fuel filter
6
7
8
9
10
Parking brake cable
Rear axle
Fuel tank
Exhaust pipe
Shock absorber
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
1-7
Major tune-up
2 Introduction
This Chapter is designed to help the home mechanic maintain the
Jeep Cherokee or Comanche with the goals of maximum performance,
economy, safety and reliability in mind.
Included is a master maintenance schedule (page 33), followed by
procedures dealing specifically with each item on the schedule. Visual
checks, adjustments, component replacement and other helpful items
are included. Refer to the accompanying illustrations of the engine compartment and the underside of the vehicle for the locations of various
components.
Servicing your vehicle in accordance with the mileageltime maintenance schedule and the step-by-step procedures will result in a planned
maintenance program that should produce a long and reliable service
life. Keep in mind that it is a comprehensive plan, so maintaining some
items but not others at the specified intervals will not produce the same
results.
As you service your vehicle, you will discover that many of the procedures can - and should - be grouped together because of the nature
of the particular procedure you're performing or because of the close
proximity of t w o otherwise unrelated components to one another.
For example, if the vehicle is raised for chassis lubrication, you should
inspect the exhaust, suspension, steering and fuel systems while you're
under the vehicle. When you're rotating the tires, it makes good sense
to check the brakes since the wheels are already removed. Finally, let's
suppose you have to borrow or rent a torque wrench. Even if you only
need it to tighten the spark plugs, you might as well check the torque
of as many critical fasteners as time allows.
The first step in this maintenance program is to prepare yourself
before the actual work begins. Read through all the procedures you're
planning to do, then gather up all the parts and tools needed. If it looks
like you might run into problems during a particular job, seek advice
from a mechanic or an experienced do-it-yourselfer.
3
Tune-up general information
The term tune-up is used in this manual to represent a combination
of individual operations rather than one specific procedure.
If, from the time the vehicle is new, the routine maintenance schedule
is followed closely and frequent checks are made of fluid levels and
high wear items, as suggested throughout this manual, the engine will
be kept in relatively good running condition and the need for additional
work will be minimized.
More likely than not, however, there will be times when the engine
is running poorly due to lack of regular maintenance. This is even more
likely if a used vehicle, which has not received regular and frequent
maintenance checks, is purchased. In such cases, an engine tune-up
will be needed outside of the regular routine maintenance intervals.
The first step in any tune-up or diagnostic procedure to help correct
a poor running engine is a cylinder compression check. A compression
check (see Chapter 2 Part D) will help determine the condition of internal
engine components and should be used as a guide for tune-up and repair
procedures. If, for instance, a compression check indicates serious internal engine wear, a conventional tune-up will not improve the performance of the engine and would be a waste of time and money.
Because of its importance, the compression check should be done by
someone with the right equipment and the knowledge to use it properly.
The following procedures are those most often needed to bring a
generally poor running engine back into a proper state of tune.
All items listed under Minor tune-up plus . . .
Check the EGR system (Section 42)
Check the ignition system (Chapter 5)
Check the charging system (Chapter 5)
Check the fuel system (Section 21
Replace the air and PCV filters (Section 32)
Replace the distributor cap and rotor (Section 45)
Replace the spark plug wires (Section 44)
4
Fluid level checks
Note: The following are fluid level checks to be done on a 250 mile
or weekly basis. Additional fluid level checks can be found in specific
maintenance procedures which follow. Regardless of intervals, be alert
to fluid leaks under the vehicle which would indicate a fault to be carrected immedia tely.
1 Fluids are an essential part of the lubrication, cooling, brake, clutch
and windshield washer systems. Because the fluids gradually become
depleted and/or contaminated during normal operation of the vehicle,
they must be periodically replenished. See Recommended lubricants
and fluids at the beginning of this Chapter before adding fluid to any
of the following components. Note: The vehicle must be on level ground
when fluid levels are checked.
Engine oil
Refer to illustrations 4.4 and 4.6
2 The engine oil level is checked with a dipstick that extends through
a tube and into the oil pan at the bottom of the engine.
3 The oil level should be checked before the vehicle has been driven,
or about 15 minutes after the engine has been shut off. If the oil is
checked immediately after driving the vehicle, some of the oil will remain in the upper engine components, resulting in an inaccurate reading
on the dipstick.
4 Pull the dipstick from the tube and wipe all the oil from the end
with a clean rag or paper towel. Insert the clean dipstick all the way
back into the tube, then pull it out again. Note the oil at the end of
the dipstick. Add oil as necessary to keep the level between the ADD
mark and the FULL mark on the dipstick (see illustration).
5 Do not overfill the engine by adding too much oil since this may
result in oil fouled spark plugs, oil leaks or oil seal failures.
Minor tune-up
Check all engine related fluids (Section 4 )
Clean, inspect and test the battery (Section 8)
Check and adjust the drivebelts (Section 26)
Replace the spark plugs (Section 43)
lnspect the distributor cap and rotor (Section 45)
lnspect the spark plug and coil wires (Section 44)
Check and adjust the ignition timing (Section 33)
Check the PCV valve or CCV hose(Section 40)
Check the air and PCV filters (Section 32)
Check the cooling system (Section 9)
Check all underhood hoses (Section 10)
4.4 Checking the oil level on an inline six-cylinder engine (on
engines, the dipstick is on the driver's side of the engine; on fourcylinder engines, it's on the passenger's side) - the oil level
should be at or near the FULL mark
if it isn't, add enough oil
to bring the level t o or near the FULL mark (it takes one quart t o
raise the level from ADD to FULL)
1
The Motor Manual Guy
1-8
Chapter 1
Tune-up and routine maintenance
RADIATOR
CAP
COOLANT
RESERVE
BOTTLE
4.6 The twist-off oil filler cap is located on the rocker cover
(except on V6 models, which have it mounted on top of a filler
tube on the driver's side of the engine) - always make sure the
area around this opening is clean before unscrewing the cap t o
prevent dirt from contaminating the engine
4.8a On four-cylinder and V6 engines, the coolant reserve bottle
allows for contraction and expansion of the coolant - it can be
checked visually with the engine hot or cold
COOLANT PRESSURE BOTTLE
6
Oil is added to the engine after removing a cap (see illustration).
An oil can spout or funnel may help to reduce spills.
7 Checking the oil level is an important preventive maintenance step.
A consistently low oil level indicates oil leakage through damaged seals,
defective gaskets or past worn rings or valve guides. If the oil looks
milky in color or has water droplets in it, the cylinder head gasket(s)
may be blown or the head(s) or block may be cracked. The engine
should be checked immediately. The condition of the oil should also
be checked. Whenever you check the oil level, slide your thumb and
index finger up the dipstick before wiping off the oil. If you see small
dirt or metal particles clinging to the dipstick, the oil should be changed
(Section 12).
Engine coolant
Refer to illustrations 4.Ba and 4.Bb
Warning: Do not allow antifreeze to come in contact with your skin
or painted surfaces of the vehicle. Flush contaminated areas immediately with plenty of water. Don't store new coolant or leave old coolant
lying around where it's accessible to children or pets - they 're attracted
by its sweet taste. Ingestion of even a small amount of coolant can
be fatal! Wipe up garage floor and drip pan coolant spills immediately.
Keep antifreeze containers covered and repair leaks in your cooling
system immediately.
8 All vehicles covered by this manual are equipped with a pressurized
coolant recovery system. A white plastic coolant reserve or pressure
bottle located in the engine compartment is connected by a hose to
the radiator or radiator filler neck (see illustrations). If the engine
overheats on four-cylinder or V6 engines, coolant escapes through a
valve in the radiator cap and travels through the hose into the reservoir.
As the engine cools, the coolant is automatically drawn back into the
cooling system t o maintain the correct level. On inline six-cylinder
engines there is no radiator cap. Instead, the cap on the pressure bottle is pressurized. The bottle is part of the cooling system, and coolant
flows through it whenever the engine is running. The cap should only
be removed when the engine is off and cold.
9 The coolant level in the reservoir should be checked regularly.
Warning: Do not remove the radiator cap orpressure bottle cap to check
the coolant level when the engine is warm. On four-cylinder or V6
engines, the coolant level in the reservoir
kept between the
should be
vfinder
FULL and ADD marks on the side of the reservoir. On inline six-c ,.
engines, remove the pressure bottle cap with the engine off and cold.
Look down into the bottle and make sure the coolant is at the top of
the post (full) or no lower than the notch (add). If it is necessary to
add coolant, allow the engine t o cool, then remove the cap from the
reservoir and add a 50/50 mixture of ethylene glycol-based antifreeze
and water.
4.8b On inline six-cylinder engines, check the coolant
level at the coolant pressure bottle: the engine must be off
and cold, since the bottle is pressurized along with the rest
of the cooling system - remove the cap and look inside
the reservoir - the coolant level is correct if it's between
the top of the post (FULL) and the notch i n the post (ADD)
1 0 Drive the vehicle and recheck the coolant level. If only a small
amount of coolant is required to bring the system up to the proper level,
water can be used. However, repeated additions of water will dilute
the antifreeze and water solution. In order to maintain the proper ratio
of antifreeze and water, always top up the coolant level with the correct
mixture. An empty plastic milk jug or bleach bottle makes an excellent
container for mixing coolant. Do not use rust inhibitors or additives.
11 If the coolant level drops consistently, there may be a leak in the
system. Inspect the radiator, hoses, filler cap, drain plugs and water
pump (see Section 9). If no leaks are noted, have the radiator cap
pressure tested by a service station.
12 If you have t o remove the radiator cap, wait until the engine has
cooled, then wrap a thick cloth around the cap and turn it to the first
stop. If coolant or steam escapes, let the engine cool down longer,
then remove the cap.
1 3 Check the condition of the coolant as well. It should be relatively
clear. If it's brown or rust colored, the system should be drained, flushed
and refilled. Even if the coolant appears to be normal, the corrosion
inhibitors wear out, so it must be replaced at the specified intervals.
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
4.14 The windshield washer fluid reservoir is located on
the driver's side of the engine compartment - keep the
level at or near the FULL line; fluid can be added
after flipping up the cap
4.18 The clutch master cylinder is located next t o the
brake booster - maintain the fluid level between the
MAX and MIN marks
.M...A..X..I.M
. . U.M
..
Windshield washer fluid
Refer to illustration 4.14
14 Fluid for the windshield washer system is located in a plastic reservoir in the engine compartment (see illustration).
1 5 In milder climates, plain water can be used in the reservoir, but
it should be kept no more than 2/3 full to allow for expansion if the
water freezes. In colder climates, use windshield washer system antifreeze, available at any auto parts store, t o lower the freezing point
of the fluid. Mix the antifreeze with water in accordance with the
manufacturer's directions on the container. Caution: Don't use cooling
system antifreeze - it will damage the vehicle's paint.
16 To help prevent icing in cold weather, warm the windshield with
the defroster before using the washer.
1-9
FILL
.
.
INDICATOR MAR'.K
RESERVOIR
\\
Battery electrolyte
1 7 All vehicles with which this manual is concerned are equipped with
a battery which is permanently sealed (except for vent holes) and has
no filler caps. Water doesn't have to be added to these batteries at
any time. If a maintenance-type battery is installed, the caps on the
top of the battery should be removed periodically to check for a low
water level. This check is most critical during the warm summer months.
Brake and clutch fluid
Refer to illustrations 4. 1 8, 4.19a, 4.19b and 4.19c
1 8 The brake master cylinder is mounted on the front of the power
booster unit in the engine compartment. The clutch master cylinder
used on manual transmissions is mounted adjacent to it on the firewall
(see illustration).
19 If the vehicle is equipped with ABS brakes, the fluid inside the reservoir is readily visible. The level should be at the MAX mark (see illustration). On non-ABS vehicles, use a screwdriver to pry the clip free; then
remove the cover (see illustrations). Be sure t o wipe the top of the
On vehicles without ABS brakes, pry the clip off
the brake master cylinder cover with a screwdriver
4.19a On ABS-equipped vehicles, the fluid level should be
maintained at or near the top of the MAX indicator mark unscrew the cap t o add fluid
LEVEL
4.19c On reservoirs with a clip-on cover, the brake fluid level
should be kept 114-inch below the top edge of the reservoir
1
The Motor Manual Guy
Chapter 1
1-10
Tune-up and routine maintenance
reservoir cap or cover with a clean rag to prevent contamination of
the brake and/or clutch system before removing the cover.
2 0 When adding fluid, pour it carefully into the reservoir to avoid spilling it onto surrounding painted surfaces. Be sure the specified fluid
is used, since mixing different types of brake fluid can cause damage
t o the system. See Recommended lubricants and fluids at the front
of this Chapter or your owner's manual. Warning: Brake fluid can harm
your eyes and damage painted surfaces, so use extreme caution when
handling or pouring it. Do not use brake fluid that has been standing
open or is more than one year old. Brake fluid absorbs moisture from
the air. Excess moisture can cause a dangerous loss of braking effectiveness.
21 A t this time the fluid and master cylinder can be inspected for contamination. The system should be drained and refilled if deposits, dirt
particles or water droplets are seen in the fluid.
2 2 After filling the reservoir t o the proper level, make sure the cover
or cap is on tight to prevent fluid leakage.
23 The brake fluid level in the brake master cylinder will drop slightly
as the pads and the brake shoes at each wheel wear down during normal operation. If the master cylinder requires repeated additions to keep
it at the proper level, it's an indication of leakage in the brake system,
which should be corrected immediately. Check all brake lines and connections (see Section 2 0 for more information).
2 4 If, upon checking the master cylinder fluid level, you discover one
or both reservoirs empty or nearly empty, the brake system should be
bled (Chapter 9).
5
Tire and tire pressure checks
Refer to illustrations 5.2, 5.3, 5.4a, 5.4b and 5.8
1 Periodic inspection of the tires may spare you the inconvenience
of being stranded with a flat tire. It can also provide you with vital information regarding possible problems in the steering and suspension
systems before major damage occurs.
2 The original tires on this vehicle are equipped with 112-inch side
Condition
Probable cause
Corrective action
Underinflation
• (both
sides wear)
Measure and
• adjust
pressure.
Incorrect wheel
• camber
(one
Repair or replace
• axle
and suspen-
side wear)
•
• Lack of rotation
Hard cornering
5.2 A tire tread depth indicator should be used to monitor
tire wear - they are available at auto parts stores and
service stations and cost very little
bands that will appear when tread depth reaches 1 /1 6-inch, but they
don't appear until the tires are worn out. Tread wear can be monitored
with a simple, inexpensive device known as a tread depth indicator
(see illustration).
3 Note any abnormal tread wear (see illustration). Tread pattern
irregularities such as cupping, flat spots and more wear on one side
than the other are indications of front end alignment and/or balance
problems. If any of these conditions are noted, take the vehicle to a
tire shop or service station to correct the problem.
4 Look closely for cuts, punctures and embedded nails or tacks.
Condition
Feathered edge
• Adjust toe-in.
camber
• orIncorrect
caster
Repair or replace
• axle
and suspen-
•
• Rotate tires.
1/
f
I ' ( I I I,.,, ....
Toe weal
• Overinflation
• Lack of rotation
l
• Incorrect toe
sion parts.
Shoulder wear
and
• Measure
adjust pressure
sion parts.
• Rotate tires.
Repair or replace
• Malfunctioning
• suspension
suspension
parts.
Unbalanced
wheel
Balance
or
•
• replace.
Out-of-round
• brake drum
• Turn or replace.
• Lack of rotation
Center wear
Corrective action
Reduce speed.
ll 1•1i '/ ' I
I I
Probable cause
Uneven wear
• Rotate tires.
I
LI--------...&.._______.________..,___________...._c_a_u_se-(-sl_ _ _..,__ _ _ _ _ _ _
5.3 This chart will help you determine the condition of the tires, the probable
of abnormal
wear and the corrective action necessary
j
II
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
1-11
5.4a If a tire loses air on a steady basis, check the valve
core first to make sure it's snug (special inexpensive
wrenches are commonly available at auto parts stores)
5.4b If the valve core is tight, raise the corner of the
vehicle with the low tire and spray a soapy water solution
onto the tread as the tire is'turned - slow leaks will
cause small bubbles to appear
Sometimes a tire will hold air pressure for a short time or leak down
very slowly after a nail has embedded itself in the tread. If a slow leak
persists, check the valve stem core to make sure it's tight (see illustration). Examine the tread for an object that may have embedded itself
in the tire or for a "plug" that may have begun to leak (radial tire punctures are repaired with a plug that's installed in a puncture). If a puncture
is suspected, it can be easily verified by spraying a solution of soapy
water onto the puncture area (see illustration). The soapy solution will
bubble if there's a leak. Unless the puncture is unusually large, a tire
shop or service station can usually repair the tire.
5 Carefully inspect the inner sidewall of each tire for evidence of
brake fluid leakage. If you see any, inspect the brakes immediately.
6 Correct air pressure adds miles to the lifespan of the tires, improves
mileage and enhances overall ride quality. Tire pressure cannot be
accurately estimated by looking at a tire, especially if it's a radial. The
correct tire pressures are located on a label on the inside of the glove
box door. A tire pressure gauge is essential. Keep an accurate gauge
in the vehicle. The pressure gauges attached to the nozzles of air hoses
at gas stations are often inaccurate.
7 Always check tire pressure when the tires are cold. Cold, in this
case, means the vehicle has not been driven over a mile in the three
hours preceding a tire pressure check. A pressure rise of four to eight
pounds is not uncommon once the tires are warm.
8 Unscrew the valve cap protruding from the wheel or hubcap and
push the gauge firmly onto the valve stem (see illustration). Note the
reading on the gauge and compare the figure to the recommended tire
pressure shown on the placard on the driver's side door pillar. Be sure
to reinstall the valve cap t o keep dirt and moisture out of the valve
stem mechanism. Check all four tires and, if necessary, add enough
air to bring them up to the recommended pressure.
9 Don't forget to keep the spare tire inflated to the specified pressure
(refer to your owner's manual or the tire sidewall). Note that the
pressure recommended for the compact spare is higher than for the
tires on the vehicle.
5.8
To extend the life of the tires, check the air pressure
at least once a week with an accurate gauge
{don't forget the spare!)
6
Automatic transmission fluid level check
Refer to illustration 6.6
1 The automatic transmission fluid level should be carefully maintained. Low fluid level can lead to slipping or loss of drive, while overfilling can cause foaming and loss of fluid.
2 Warm the transmission by driving the vehicle at least 15 miles.
With the parking brake set, start the engine, then move the shift lever
through all the gear ranges, ending in Neutral. The fluid level must be
checked with the vehicle level and the engine running at idle.
3 With the transmission at normal operating temperature, remove
the dipstick from the filler tube. The dipstick is located at the rear of
the engine compartment.
4 Wipe the fluid from the dipstick with a clean rag and push it back
into the filler tube until the cap seats.
5 Pull the dipstick out again and note the fluid level.
6 The level should be between the ADD and FULL marks (see illustra-
6.6 The automatic transmission dipstick is located i n a
long tube located at the rear of the engine compartment
-1'
The Motor Manual Guy
1-12
Chapter 1
Tune-up and routine maintenance
tion). If additional fluid is required, add it directly into the tube using
a funnel. It takes about one pint to raise the level from the ADD mark
to the FULL mark with a warm transmission, so add the fluid a little
at a time and keep checking the level until it's correct.
7 The condition of the fluid should also be checked along with the
level. If the fluid at the end of the dipstick is a dark reddish-brown color,
or if it smells burned, it should be changed. If you are in doubt about
the condition of the fluid, purchase some new fluid and compare the
t w o for color and smell.
battery cells is actually dilute sulfuric acid, which will cause injury if
splashed on your skin or in your eyes. It will also ruin clothes and painted
surfaces. When removing the battery cables, always detach the negative cable first and hook it up last!
1 Battery maintenance is an important procedure which will help ensure that you're not stranded because of a dead battery. Several tools
are required for this procedure (see illustration).
2 Before servicing the battery, always turn the engine and all accessories off and disconnect the cable from the negative terminal.
3 A sealed (sometimes called maintenance-free) battery is standard
equipment on these vehicles. The cell caps cannot be removed, no electrolyte checks are required and water cannot be added t o the cells.
However, if an aftermarket battery that requires regular maintenance
7.6 The power steering fluid filler cap/dipstick is located
at the front of the engine - the dipstick has marks for
checking the fluid at different temperatures
7
Power steering fluid level check
Refer to illustration 7.6
1 Unlike manual steering, the power steering system relies on fluid
which may, over a period of time, require replenishing.
2 The fluid reservoir for the power steering pump is located on the
pump body at the front of the engine.
3 For the check, the front wheels should be pointed straight ahead
and the engine should be off.
4 Use a clean rag to wipe off the reservoir cap and the area around
the cap. This will help prevent any foreign matter from entering the
reservoir during the check.
5 Twist off the cap and check the temperature of the fluid at the
end of the dipstick with your finger.
6 Wipe off the fluid with a clean rag, reinsert the dipstick, then
withdraw it and read the fluid level. The level should be at the H (Hot)
mark if the fluid was hot to the touch (see illustration). It should be
at the C (Cold) mark if the fluid was cool to the touch. Never allow
the fluid level to drop below the ADD mark.
7 If additional fluid is required, pour the specified type directly into
the reservoir, using a funnel to prevent spills.
8 If the reservoir requires frequent fluid additions, all power steering
hoses, hose connections and the power steering pump should be carefully checked for leaks.
8
Battery check and maintenance
Refer to illustrations 8.1, 8. Ba, 8.Bb, 8.Bc and 8.Bd
Warning: Certain precautions must be followed when checking and
servicing the battery. Hydrogen gas, which is highly flammable, is
always present in the battery cells, so keep lighted tobacco and all other
open flames and sparks away from the battery. The electrolyte in the
8.1
Tools and materials required for battery maintenance
-
When removing corrosion
1 Face shield/safety goggles
with a brush, the acidic particles can easily fly up into
your eyes
2 Baking soda - A solution of baking soda and water can
be used to neutralize corrosion
3 Petroleum jelly - A layer of this on the battery posts
will help prevent corrosion
This wire brush cleaning
4 Battery post/cable cleaner
tool will remove all traces of corrosion from the battery
posts and cable clamps
Placing one of these on each
5 Treated felt washers
post, directly under the cable clamps, will help prevent
corrosion
6 Puller - Sometimes the cable clamps are very difficult
to pull off the posts, even after the nut/bolt has been
completely loosened. This tool pulls the clamp straight
up and off the post without damage
7 Battery post/cable cleaner - Here is another cleaning
tool which is a slightly different version of number 4
above, but it does the same thing
Another safety item to consider when
8 Rubber gloves
servicing the battery; remember that's acid inside the
battery!
-
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
has been installed, the following procedure can be used.
4 Check the electrolyte level in each of the battery cells. It must be
above the plates. There's usually a split-ring indicator in each cell t o
indicate the correct level. If the level is low, add distilled water only,
then install the cell caps. Caution: Overfilling the cellsmay cause electrolyte to spill over during periods of heavy charging, causing corrosion
and damage to nearby components.
5 If the positive terminal and cable clamp on your vehicle's battery
is equipped with a rubber protector, make sure that it's not torn or
damaged. It should completely cover the terminal.
6 The external condition of the battery should be checked periodically.
Look for damage such as a cracked case.
7 Check the tightness of the battery cable clamps t o ensure good
electrical connections and inspect the entire length of each cable, looking for cracked or abraded insulation and frayed conductors.
8 If corrosion (visible as white, fluffy deposits) is evident, remove
the cables from the terminals, clean them with a battery brush and
1-13
reinstall them (see illustrations). Corrosion can be kept to a minimum
by installing specially treated washers available at auto parts stores
or by applying a layer of petroleum jelly or grease t o the terminals and
cable clamps after they are assembled.
9 Make sure that the battery carrier is in good condition and that
the hold-down clamp bolt is tight. If the battery is removed (see Chapter 5 for the removal and installation procedure), make sure that no
parts remain in the bottom of the carrier when it's reinstalled. When
reinstalling the hold-down clamp, don't overtighten the bolt.
10 Corrosion on the carrier, battery case and surrounding areas can
be removed with a solution of water and baking soda. Apply the mixture
with a small brush, let it work, then rinse it off with plenty of clean
water.
11 Any metal parts of the vehicle damaged by corrosion should be
coated with a zinc-based primer, then painted.
1 2 Additional information on the battery, charging and jump starting
can be found in Chapter 5 and at the front of this manual.
1
8.8a Battery terminal corrosion usually appears as
light, fluffy powder
8.8c Regardless of the type of tool used t o clean the
battery posts, a clean, shiny surface should be the result
8.8b Removing the cable from a battery post with a
wrench - sometimes a special battery pliers is
required for this procedure if corrosion has caused
deterioration of the nut hex (always remove the
ground cable first and hook it up last!)
8.8d
When cleaning the cable clamps, all corrosion must
be removed (the inside of the clamp is tapered t o match
the taper on the post, so don't remove too much material)
The Motor Manual Guy
Chapter 1
1-14
9
Tune-up and routine maintenance
Cooling system check
Refer to illustration 9.4
1 Many major engine failures can be attributed t o a faulty cooling
system. If the vehicle is equipped with an automatic transmission, the
cooling system also cools the transmission fluid and thus plays an important role in prolonging transmission life.
2 The cooling system should be checked with the engine cold. Do
this before the vehicle is driven for the day or after it has been shut
off for at least three hours.
3 On four-cylinder and V6 engines, remove the radiator cap by turning
it to the left until it reaches a stop. If you hear a hissing sound (indicating there is still pressure in the system), wait until this stops. Now
press down on the cap with the palm of your hand and continue turning
t o the left until the cap can be pulled off. Thoroughly clean the cap,
inside and out, with clean water. Also clean the filler neck on the
radiator. All traces of corrosion should be removed. On inline sixcylinder engines, unscrew the cap on the coolant pressure bottle and
clean the cap. The coolant inside the radiator or pressure bottle should
be relatively transparent. If it is rust colored, the system should be
drained and refilled (Section 39). If the coolant level is not up to the
top, add additional antifreezelcoolant mixture (see Section 4).
4 Carefully check the large upper and lower radiator hoses along with
the smaller diameter heater hoses which run from the engine to the
firewall. On some models the heater return hose runs directly to the
radiator. On inline six-cylinder vehicles, also inspect the hoses attached
to the coolant pressure bottle. lnspect each hose along its entire length,
replacing any hose which is cracked, swollen or shows signs of
deterioration. Cracks may become more apparent if the hose is
squeezed (see illustration). Regardless of condition, it's a good idea
to replace hoses with new ones every t w o years.
5 Make sure that all hose connections are tight. A leak in the cooling
svstem will usually show up as white or rust colored deposits on the
A L W A Y S C H E C K hose for chafed
or burned areas that may cause an
untimely and costly failure
SOFT hose indicates inside deterioration
This deterioration can contaminate the
cooling system and cause particles to
clog the radiator
H A R D E N E D hose can fail at any time
Tightening hose clamps will not seal the
c.:onnect1on or stop leaks
\
\
/ ~
(
'~;n
SWOLLEN hose or oil soaked ends in
dicate danger and possible failure from
or grease contammat1on. Squeeze
oil
the hose t o locate cracks and breaks
that cause leaks
9.4 Hoses, like drivebelts. have a habit of failing at the
worst possible time - t o prevent the inconvenience
of a blown radiator or heater hose, inspect them
carefully as shown here
areas adjoining the leak. If wire-type clamps are used at the ends of
the hoses, it may be a good idea to replace them with more secure
screw-type clamps.
6 Use compressed air or a soft brush t o remove bugs, leaves, etc.
from the front of the radiator or air conditioning condenser. Be careful
not to damage the delicate cooling fins or cut yourself on them.
7 Every other inspection, or at the first indication of cooling system
problems, have the cap and system pressure tested. If you don't have
a pressure tester, most gas stations and repair shops will do this for
a minimal charge.
10 Underhood hose check and replacement
General
1 Caution: Replacement o f air conditioning hoses must be left to a
dealer service department or air conditioning shop that has the e q u i p
ment to depressurize the system safely. Never remove air conditioning
components or hoses until the system has been depressurized.
2 High temperatures in the engine compartment can cause the deterioration of the rubber and plastic hoses used for engine, accessory and
emission systems operation. Periodic inspection should be made for
cracks, loose clamps, material hardening and leaks. Information specific
to the cooling system hoses can be found in Section 9.
3 Some, but not all, hoses are secured to the fittings with clamps.
Where clamps are used, check to be sure they haven't lost their tension,
allowing the hose t o leak. If clamps aren't used, make sure the hose
has not expanded and/or hardened where it slips over the fitting, allowing it t o leak.
Vacuum hoses
4 It's quite common for vacuum hoses, especially those in the emissions system, to be color coded or identified by colored stripes molded
into them. Various systems require hoses with different wall thicknesses, collapse resistance and temperature resistance. When replacing
hoses, be sure the new ones are made of the same material.
5 Often the only effective way to check a hose is to remove it completely from the vehicle. If more than one hose is removed, be sure
to label the hoses and fittings t o ensure correct installation.
6 When checking vacuum hoses, be sure to include any plastic Tfittings in the check. lnspect the fittings for cracks and the hose where
it fits over the fitting for distortion, which could cause leakage.
7 A small piece of vacuum hose (114-inch inside diameter) can be
used as a stethoscope t o detect vacuum leaks. Hold one end of the
hose t o your ear and probe around vacuum hoses and fittings, listening for the "hissing" sound characteristic of a vacuum leak. Warning:
When probing with the vacuum hose stethoscope, be very careful n o t
to come into contact with moving engine components such as the drivebelt, cooling fan, etc.
Fuel hoses
Warning: There are certain precautions which must be taken when inspecting or servicing fuel system components. Work in a well ventilated
area and do n o t allow open flames (cigarettes, appliance pilot lights,
etc.) or bare light bulbs near the work area. Mop up any spills immediately and do n o t store fuel soaked rags where they could ignite.
On vehicles equipped with fuel injection, the fuel system is under
pressure, so i f any fuel lines are to be disconnected, the pressure in
the system must be relieved first (see Chapter 4 for more information).
8 Check all rubber fuel lines for deterioration and chafing. Check
especially for cracks in areas where the hose bends and just before
fittings, such as where a hose attaches to the fuel filter.
9 High quality fuel line, usually identified by the word Fluroelastomer
printed on the hose, should be used for fuel line replacement. Never,
under any circumstances, use unreinforced vacuum line, clear plastic
tubing or water hose for fuel lines.
10 Spring-type clamps are commonly used on fuel lines. These clamps
often lose their tension over a period of time, and can be "sprung"
during removal. Replace all spring-type clamps with screw clamps
whenever a hose is replaced.
Metal lines
1 1 Sections of metal line are often used for fuel line between the fuel
pump and carburetor or fuel injection unit. Check carefully t o be sure
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
the line has not been bent or crimped and that cracks have not started
in the line.
1 2 If a section of metal fuel line must be replaced, only seamless steel
tubing should be used, since copper and aluminum tubing don't have
the strength necessary to withstand normal engine vibration.
1 3 Check the metal brake lines where they enter the master cylinder
and brake proportioning unit (if used) for cracks in the lines or loose
fittings. Any sign of brake fluid leakage calls for an immediate thorough
inspection of the brake system.
11
Wiper blade inspection and replacement
Refer to illustrations 1 1.6a and 1 1.6b
1 The windshield wiper and blade assembly should be inspected
periodically for damage, loose components and cracked or worn blade
elements.
2 Road film can build up on the wiper blades and affect their efficiency, so they should be washed regularly with a mild detergent
solution.
3 The action of the wiping mechanism can loosen the bolts, nuts
and fasteners, so they should be checked and tightened, as necessary,
at the same time the wiper blades are checked.
4 If the wiper blade elements (sometimes called inserts) are cracked,
worn or warped, the blade/arm assemblies should be replaced with
new ones.
5 Pull the wiper blade/arm assembly away from the glass.
6 Lift the release lever and slide the blade assembly off the wiper
arm and over the retaining stud (see illustrations).
7 Compare the new blade/arm assembly to the old one for length,
design, etc.
8 Reinstall the blade assembly on the arm, wet the windshield and
check for proper operation.
1-15
12 Engine oil and filter change
Refer to illustrations 12.3, 12.9, 12. 14, 12. 16 and 12. 18
1 Frequent oil changes are the most important preventive maintenance procedures that can be done by the home mechanic. As engine
oil ages, it becomes diluted and contaminated, which leads to premature
engine wear.
2 Although some sources recommend oil filter changes every other
oil change, we feel that the minimal cost of an oil filter and the relative
ease with which it is installed dictate that a new filter be installed every
time the oil is changed.
3 Gather together all necessary tools and materials before beginning
this procedure (see illustration).
4 You should have plenty of clean rags and newspapers handy t o
mop up any spills. Access to the underside of the vehicle is greatly
improved if the vehicle can be lifted on a hoist, driven onto ramps or
supported by jackstands. Warning: Do not work under a vehicle which
is supported only by a bumper, hydraulic or scissors-type jack,
11.6a On windshield wipers, insert a screwdriver under
the wiper release lever, lift up and slide the windshield
wiper assembly off the arm stud
12.3
11.6b
On rear wipers, lift the release lever (A), then slide
the wiper off the stud
These tools are required when changing the
engine oil and filter
1 Drain pan - It should be fairly shallow in depth, but
wide in order to prevent spills
2 Rubber gloves - When removing the drain plug and
filter i t is inevitable that you will get oil on your hands
(the gloves will prevent burns)
3 Breaker bar - Sometimes the oil drain plug is pretty
tight and a long breaker bar is needed to loosen i t
4 Socket
To be used with the breaker bar or a ratchet
(must be the correct size to fit the drain plug)
5 Filter wrench
This is a metal band-type wrench,
which requires clearance around the filter to be effective
6 Filter wrench
This type fits on the bottom of the
filter and can be turned with a ratchet or breaker bar
(different size wrenches are available for different types
of filters)
1
The Motor Manual Guy
1-16
Chapter 1
Tune-up and routine maintenance
5 If this is your first oil change, get under the vehicle and familiarize
yourself with the locations of the oil drain plug and the oil filter. The
engine and exhaust components will be warm during the actual work,
so note how they are situated to avoid touching them when working
under the vehicle.
6 Warm the engine t o normal operating temperature. If the new oil
or any tools are needed, use this warm-up time to gather everything
necessary for the job. The correct type of oil for your application can
be found in Recommended lubricants and fluids at the beginning of
this Chapter.
7 With the engine oil warm (warm engine oil will drain better and
more built-up sludge will be removed with it), raise and support the
vehicle. Make sure it's safely supported!
8 Move all necessary tools, rags and newspapers under the vehicle.
Set the drain pan under the drain plug. Keep in mind that the oil will
initially flow from the pan with some force; position the pan accordingly.
9 Being careful not to touch any of the hot exhaust components,
use a wrench to remove the drain plug near the bottom of the oil pan
(see illustration). Depending on how hot the oil is, you may want to
wear gloves while unscrewing the plug the final few turns.
10 Allow the old oil to drain into the pan. It may be necessary to move
the pan as the oil flow slows to a trickle.
1 1 After all the oil has drained, wipe off the drain plug with a clean
rag. Small metal particles may cling to the plug and would immediately
contaminate the new oil.
12 Clean the area around the drain plug opening and reinstall the plug.
Tighten the plug securely with the wrench. If a torque wrench is
available, use it t o tighten the plug.
13 Move the drain pan into position under the oil filter.
14 Use the filter wrench to loosen the oil filter (see illustration). Chain
or metal band filter wrenches may distort the filter canister, but it
doesn't matter since the filter will be discarded anyway.
1 5 Completely unscrew the old filter. Be careful; it's full of oil. Empty
the oil inside the filter into the drain pan.
1 6 Compare the old filter with the new orie t o make sure they're the
same type (see illustration).
17 Use a clean rag to remove all oil, dirt and sludge from the area where
the oil filter mounts to the engine. Check the old filter t o make sure
the rubber gasket isn't stuck to the engine. If the gasket is stuck to
the engine (use a flashlight if necessary), remove it.
18 Apply a light coat of clean oil to the rubber gasket on the new oil
filter (see illustration).
12.9 To avoid rounding off the corners of the drain plug, use
the correct size box-end wrench or six-point socket t o remove i t
12.14 The oil filter is usually on very tight and will require
a special wrench for removal - DO NOT use the wrench
to tighten the new filter
12.16 Some later inline six-cylinder engines use a metric
20 m m filter - if the old filter is so marked, make
sure the new one is too
12.18
Lubricate the gasket with clean engine oil before
installing the filter on the engine
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Chapter 1
Tune-up and routine maintenance
1-17
19 Attach the new filter to the engine, following the tightening directions printed on the filter canister or packing box. Most filter manufacturers recommend against using a filter wrench due t o the possibility
of overtightening and damage to the seal.
2 0 Remove all tools, rags, etc. from under the vehicle, being careful
not to spill the oil in the drain pan, then lower the vehicle.
21 Move to the engine compartment and locate the oil filler cap.
2 2 If an oil can spout is used, push the spout into the top of the oil
can and pour the fresh oil through the filler opening. A funnel may also
be used.
23 On four-cylinder and V6 engines, pour four quarts of fresh oil into
the engine. On inline six-cylinder engines, pour in five quarts. Wait a
few minutes to allow the oil to drain into the pan, then check the level
on the oil dipstick (see Section 4 if necessary). If the oil level is above
the ADD mark, start the engine and allow the new oil to circulate.
2 4 Run the engine for only about a minute checking the pressure gauge
or indicator light to make sure normal oil pressure is achieved. Shut
off the engine, Immediately look under the vehicle and check for leaks
at the oil pan drain plug and around the oil filter. If either is leaking,
tighten with a bit more force.
25 With the new oil circulated and the filter now completely full,
recheck the level on the dipstick and add more oil as necessary.
26 During the first few trips after an oil change, make it a point to
check frequently for leaks and proper oil level.
27 The old oil drained from the engine cannot be reused in its present
state and should be disposed of. Oil reclamation centers, auto repair
shops and gas stations will normally accept the oil, which can be refined
and used again. After the oil has cooled it can be drained into a suitable
container (capped plastic jugs, topped bottles, milk cartons, etc.) for
transport to one of these disposal sites.
1
13 Chassis lubrication
Refer to illustrations 13.1, 13.9, 13.10, 13. 1 1 and 13. 14
1 Refer to Recommended lubricants and fluids at the front of this
Chapter to obtain the necessary grease, etc. You will also need a grease
gun (see illustration). Occasionally plugs will be installed rather than
grease fittings. If so, grease fittings will have to be purchased and installed.
2 Look under the vehicle for grease fittings or plugs on the steering,
suspension, and driveline components. They are normally found on
the balljoints, tie-rod ends and universal joints. If there are plugs, remove
them and buy grease fittings, which will thread into the component.
A dealer or auto parts store will be able t o supply the correct fittings.
Straight, as well as angled, fittings are available.
3 For easier access under the vehicle, raise it with a jack and place
jackstands under the frame. Make sure it is safely supported by the
stands. If the wheels are to be removed at this interval for tire rotation
or brake inspection, loosen the lug nuts slightly while the vehicle is
still on the ground.
4 Before beginning, force a little grease out of the nozzle to remove
any dirt from the end of the gun. Wipe the nozzle clean with a rag.
5 With the grease gun and plenty of clean rags, crawl under the vehicle and begin lubricating the components.
6 Wipe the balljoint grease fitting nipple clean and push the nozzle
firmly over it. Squeeze the trigger on the grease gun to force grease
into the component. The balljoints should be lubricated until the rubber seal is firm to the touch. Do not pump too much grease into the
fittings as it could rupture the seal. For all other suspension and steering components, continue pumping grease into the fitting until it oozes
out of the joint between the t w o components. If it escapes around the
grease gun nozzle, the nipple is clogged or the nozzle is not completely
seated on the fitting. Resecure the gun nozzle to the fitting and try
again. If necessary, replace the fitting with a new one.
7 Wipe the excess grease from the components and the grease fitting.
Repeat the procedure for the remaining fittings.
8 On models where the manual transmission shift linkage is accessible, lubricate the shift linkage with a little multi-purpose grease.
9 On 4WD models, lubricate the front driveshaft Constant Velocity
(CV) joint, located at the transfer case end, using a special needle-like
adaptor on the grease gun (see illustration). Lubricate the transfer case
shift mechanism contact surfaces with clean engine oil.
1 0 If equipped, lubricate the driveshaft slip joints by pumping grease
13.1
Materials required for chassis and body lubrication
Engine o i l - Light engine oil in a can like this can be
used for door and hood hinges
2 Graphite spray - Used to lubricate lock cylinders
3 Grease - Grease, in a variety of types and weights, is
available for use in a grease gun. Check the
Specifications for your requirements
4 Grease gun - A common grease gun, shown here with
a detachable hose and nozzle, is needed for chassis
lubrication. After use, clean i t thoroughly!
13.9 I n addition to the conventional universal joints at each end
of the driveshaft, 4WD models have a Constant Velocity (CV)
joint which requires a needle-like adaptor on the grease gun the arrows show the locations of the CV joint grease fittings
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Chapter 1
1-18
Tune-up and routine maintenance
13.10 The slip joint grease fitting is located on the collar pump grease into i t until it comes out of the slip joint seal
into the fitting until it can be seen coming out of the slip joint seal (see
illustration)
11 Lubricate conventional universal joints until grease can be seen
coming out of the contact points (see illustration).
12 While you are under the vehicle, clean and lubricate the parking
brake cable along with the cable guides and levers. This can be done
by smearing some chassis grease onto the cable and its related parts
with your fingers.
13 The manual steering gear seldom requires the addition of lubricant,
but if there is obvious leakage of grease at the seals, remove the plug
or cover and check the lubricant level. If the level is low, add the
specified lubricant.
1 4 Lubricate the contact points on the steering knuckle and adjustment bolt (see illustration).
1 5 Open the hood and smear a little chassis grease on the hood latch
mechanism. Have an assistant pull the hood release lever from inside
the vehicle as you lubricate the cable at the latch.
1 6 Lubricate all the hinges (door, hood, etc.) with engine oil t o keep
them in proper working order.
17 The key lock cylinders can be lubricated with spray-on graphite
or silicone lubricant, which is available at auto parts stores.
18 Lubricate the door weatherstripping with silicone spray. This will
reduce chafing and retard wear.
14
13.1 1
Pump grease into conventional universal joints until
it can be seen coming out of the contact surfaces
13. 14 Use white lithium base grease t o lubricate the
contact points on the steering knuckle and adjustment bolt
Suspension and steering check
Refer to illustration 14.4
1 Indications of a fault in these systems are excessive play in the
steering wheel before the front wheels react, excessive sway around
corners, body movement over rough roads, noise from the axle or wheel
areas or binding at some point as the steering wheel is turned.
2 Raise the front of the vehicle periodically and visually check the
suspension and steering components for wear. Because of the work
t o be done, make sure the vehicle cannot fall from the stands.
3 Check the wheel bearings. Do this by spinning the front wheels.
Listen for any abnormal noises and watch to make sure the wheel spins
true (doesn't wobble). Grab the top and bottom of the tire and pull
in-and-out on it. Notice any movement which would indicate a loose
wheel bearing assembly. If the bearings are suspect, refer t o Section 38
(for 2WD vehicles) and Chapter 10 for more information.
4 The front axle Constant Velocity (CV) joints on some 4WD models
are protected by rubber boots. Check the boots for cuts, wear and signs
of leaking grease (see illustration). The boots must be replaced if they
are damaged, otherwise the CV joint will be contaminated and eventually fail (see Chapter 8).
5 From under the vehicle, check for loose bolts, broken or disconnected parts and deteriorated rubber bushings on all suspension and
steering components. Look for grease or fluid leaking from the steering
assembly. Check the power steering hoses and connections for leaks.
6 Have an assistant turn the steering wheel from side-to-side and
check the steering components for free movement, chafing and binding.
If the steering doesn't react simultaneously with the movement of the
steering wheel, try to determine where the slack is located.
14.4
Check the rubber CV joint boots for wear, damage
and leaking grease
The Motor Manual Guy
Chapter 1
15
Tune-up and routine maintenance
Exhaust system check
1 With the engine cold (at least three hours after the vehicle has
been driven), checkthe complete exhaust system from the manifold
to the end of the tailpipe. Be careful around the catalytic converter,
which may be hot even after three hours. The inspection should be
done with the vehicle on a hoist to permit unrestricted access. If a
hoist isn't available, raise thevehicle and support it securely on jackstands.
2 Check the exhaust pipes and connections for signs of leakage
and/or corrosion indicating a potential failure. Make sure that all
brackets and hangers
are in good condition and tight.
3 Inspect the underside of the body for holes, corrosion, open
seams, etc. which may allow exhaust gases to enter the passenger
compartment. Seal all body openings with silicone or body putty.
4 Rattles and other noises can often be traced to the exhaust system, especially the hangers, mounts and heat shields. Try to move
the pipes, mufflers and catalytic converter. If the components can
come in contact with the body or suspension parts, secure the exhaust system with new brackets and hangers.
16
Manual transmission lubricant level check
Refer to illustrations 16. 1a and 16. l b
1 The manual transmission has a fill plug which must be removed
to check the lubricant level (see illustrations). If the vehicle is raised
to gain access to the plug, be sure to support it safely on jackstands DO NOT crawl under a vehicle which is supported only by a jack!
2 Removethefill plugfromthetransmissionand use your little finger to reach inside the housing to feel the oil level. The level should
be at or near the bottom of the plug hole.
3 If it isn't, add the recommended oil through the plug hole with a
1-19
syringe or squeeze bottle.
4 Install and tighten the plug and check for leaks after the first few
miles of driving.
17
Differential lubricant level check
Refer to illustration 17.2
Note: 4WD vehicles have two differentials -one in the center of each
axle. 2WD vehicles have one differential - in the center of the rear
axle. On 4WD vehicles, be sure to check the lubricant level in both differentials.
1 The differential has a check/fill plug which must be removed to
check the lubricant level. If the vehicle must be raised to gain access
to the plug, be sure to support it safely on jackstands- DO NOT crawl
under the vehicle when it's supported only by the jack.
2 Remove the oil check/fill plug from the back of the rear differential or the front of the front differential (see illustration).
3 The oil level should be at the bottom of the plug opening. If it
isn't, use a syringe to add the specified lubricant until it just starts to
run out of the opening. On some models a tag is located in the area of
the plug which gives information regarding lubricant type, particularly on models equipped with a limited slip differential.
4 Install the plug and tighten it securely.
18
Transfer case lubricant level check (4WD models)
Refer to illustration 18.7
1 The transfer case lubricant level is checked by removing the upper plug located in the side of the case (see illustration).
2 After removing the plug, reach insidethe hole. The lubricant level should be just at the bottom of the hole. If not, add the appropriate
lubricant through the opening.
Fill P L U G
DRAIN P L U G
16.1a Manual transmission fill and drain
plug locations (AX 4/5 transmission)
17.2
16.1b The check/fill plug and drain plug on AX 15 5-speed transmission
Use the correct size open-end wrench to remove the
differential check/fill plug
18.1 The transfer case drain and fill plugs (arrows) are
located on the front face of the housing - the upper one is
the check/fill plug and the lower one is the drain plug
1
The Motor Manual Guy
Chapter 1
1-20
I ,I
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ROTATING
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19.2
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FRONT
ROTATING
4 TIRES
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Tune-up and routine maintenance
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The recommended tire rotation patterns for these vehicles
1 9 Tire rotation
Refer to illustration 19.2
1 The tires should be rotated at the specified intervals and whenever
uneven wear is noticed.
2 Refer to the accompanying illustration for the preferred tire rotation
pattern.
3 Refer t o the information in Jackingand towing at the front of this
manual for the proper procedures to follow when raising the vehicle
and changing a tire. If the brakes are to be checked, don't apply the
parking brake as stated. Make sure the tires are blocked to prevent
the vehicle from rolling as it's raised.
4 Preferably, the entire vehicle should be raised at the same time.
This can be done on a hoist or by jacking up each corner and then lowering the vehicle onto jackstands placed under the frame rails. Always
use four jackstands and make sure the vehicle is safely supported.
5 After rotation, check and adjust the tire pressures as necessary
and be sure to check the lug nut tightness.
6 For additional information on the wheels and tires, refer to Chapter 10.
20
Brake check
Refer to illustrations 20.6, 20. 12 and 20. 14
Note: For detailedphotographs of the brake system, refer to Chapter 9.
Warning: Brake system dust may contain asbestos, which is hazardous
to your health. DO NOT blow it out with compressed air and DO NOT
inhale it. DO NOT use gasoline or solvents to remove the dust. Use
brake system cleaner or denatured alcohol only.
Caution: On ABS-equipped vehicles, be careful when working in the
vicinity of the brake sensing components,
1 In addition to the specified intervals, the brakes should be inspected
every time the wheels are removed or whenever a defect is suspected.
2 To check the brakes, raise the vehicle and place it securely on
jackstands. Remove the wheels (see Jacking and towing at the front
of the manual, if necessary).
20.6 You will find an inspection hole like this i n each
placing a steel ruler across the window should
caliper
enable you t o determine the thickness of remaining pad
material for both inner and outer pads
5 The disc brake calipers, which contain the pads, are visible with
the wheels removed. There is an outer pad and an inner pad in each
caliper. All pads should be inspected.
6 Each caliper has an inspection hole to inspect the pads. Check the
thickness of the pad lining by looking into the caliper at each end and
down through the inspection hole at the top of the housing (see illustration). If the wear sensor is very close to the rotor or the pad material
has worn to about 118-inch or less, the pads should be replaced.
7 If you're unsure about the exact thickness of the remaining lining
material, remove the pads for further inspection or replacement (refer
to Chapter 9).
8 Before installing the wheels, check for leakage and/or damage
(cracks, splitting, etc.) around the brake hose connections. Replace
the hose or fittings as necessary, referring to Chapter 9.
9 Check the condition of the rotor. Look for score marks, deep
scratches and burned spots. If any of these conditions exist, the
hublrotor assembly should be removed for servicing (see Section 38
for 2WD vehicles or Chapter 9 for 4WD vehicles).
Drum brakes
10 On rear brakes, remove the drum by pulling it off the axle and brake
assembly (see Chapter 9).
11 With the drum removed, do not touch any brake dust (see the
Warning at the beginning of this Section).
12 Note the thickness of the lining material on both the front and rear
brake shoes. If the material has worn away t o within 1 /1 6-inch of the
recessed rivets or metal backing, the shoes should be replaced (see
illustration). The shoes should also be replaced if they're cracked,
Disc brakes
3 Disc brakes are used on the front wheels. Extensive rotor damage
can occur if the pads are not replaced when needed.
4 These vehicles are equipped with a wear sensor attached to the
inner pad. This is a small, bent piece of metal which is visible from
the inner side of the brake caliper. When the pad wears to the specified
limit, the metal sensor rubs against the rotor and makes a squealing
sound.
20.12 The lining thickness of the rear brake shoe is measured
from the outer surface of the lining to the metal shoe
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
1-21
and the tank is especially critical. Sometimes a rubber filler neck will
leak due to loose clamps or deteriorated rubber; these are problems
a home mechanic can usually rectify. Warning: Do not, under any
circumstances, try to repair a fuel tank yourself (except rubber components). A welding torch or any open flame can easily cause the fuel
vapors to explode if the proper precautions are n o t taken!
6 Carefully check all rubber hoses and metal lines attached t o the
fuel tank. Look for loose connections, deteriorated hoses, crimped lines
and other damage. Follow the lines to the front of the vehicle, carefully inspecting them all the way. Repair or replace damaged sections
as necessary.
7 If a fuel odor is still evident after the inspection, refer to Section 41.
22 Carburetor choke check
20.14 Peel the wheel cylinder boot back carefully and
check for leaking fluid - any leakage indicates the cylinder
must be replaced or rebuilt
glazed (shiny surface) or contaminated with brake fluid.
1 3 Make sure that all the brake assembly springs are connected and
in good condition.
1 4 Check the brake components for any signs of fluid leakage. With
your finger or a small screwdriver, carefully pry back the rubber cups
on the wheel cylinders located at the top of the brake shoes (see illustration). Any leakage is an indication that the wheel cylinders should
be overhauled immediately (Chapter 9). Also check brake hoses and
connections for signs of leakage.
1 5 Wipe the inside of the drum with a clean rag and brake cleaner
or denatured alcohol. Again, be careful not to breath the dangerous
asbestos dust.
16 Check the inside of the drum for cracks, score marks, deep
scratches and hard spots, which will appear as small discolorations.
If these imperfections cannot be removed with fine emery cloth, the
drum must be taken to a machine shop equipped to turn the drums.
17 If after the inspection process all parts are in good working condition, reinstall the brake drum (see Chapter 9).
18 Install the wheels and lower the vehicle.
Parking brake
19 The parking brake operates from a foot pedal or hand lever and
locks the rear brake system. The easiest, and perhaps most obvious
method of periodically checking the operation of the parking brake assembly is to park the vehicle on a steep hill with the parking brake set
and the transmission in Neutral. If the parking brake cannot prevent
the vehicle from rolling, it's in need of adjustment (see Chapter 9).
21 Fuel system check
Warning: Take certain precautions when inspecting or servicing the
fuel system components. Work in a well ventilated area and don't a/lo w
open flames (cigarettes, appliance pilot lights, etc.) in the work area.
Mop up spills immediately and don't store fuel soaked rags where they
could ignite. On fuel injection equippedmodels the fuel system is under
pressure. No components should be disconnected until the pressure
has been relieved (see Chapter 4).
1 On all models, the fuel tank is located under the rear of the vehicle,
covered by a shield.
2 The fuel system is most easily checked with the vehicle raised on
a hoist so the components underneath the vehicle are readily visible
and accessible.
3 If the smell of gasoline is noticed while driving or after the vehicle
has been in the sun, the system should be thoroughly inspected immediately.
4 Remove the gas tank cap and check it for damage, corrosion and
an unbroken sealing imprint on the gasket. Replace the cap with a new
one if necessary.
5 With the vehicle raised, check the gas tank and filler neck for punctures, cracks and other damage. The connection between the filler neck
1 The choke operates oniy when the engine is cold, so this check
should be performed before the engine has been started for the da y.
2 Remove the top plate of the air cleaner assembly. It's usually he Id
in place by a wing nut at the center. If any vacuum hoses must be
disconnected, make sure you tag the hoses for reinstallation in their
original positions. Place the top plate and wing nut aside, out of the
way of moving engine components.
3 Look at the center of the air cleaner housing. You will notice a flat
plate at the carburetor opening. This is the choke plate.
4 Press the accelerator pedal to the floor. The plate should close completely. Start the engine while you watch the choke plate. Don't position your face near the carburetor, as the engine could backfire, causing serious burns. When the engine starts, the choke plate should open
slightly.
5 Allow the engine to continue running at an idle speed. As the engine
warms up to operating temperature, the plate should slowly open,
allowing more air to enter through the top of the carburetor.
6 After a few minutes, the choke plate should be fully open t o the
vertical position. Tap the accelator to make sure the fast idle cam disengages.
7 You'll notice that the engine speed corresponds to the plate opening. With the plate fully closed, the engine should run at a fast idle
speed. As the plate opens and the throttle is moved t o disengage the
fast idle cam, the engine speed will decrease.
8 Refer t o Chapter 4 for specific information on adjusting and servicing the choke components.
23
1
Carburetor/throttle body mounting nut torque check
1 The carburetor or Throttle Body Injection (TBI) unit is attached to
the top of the intake manifold by several bolts or nuts. These fasteners
can sometimes work loose from vibration and temperature changes
during normal engine operation and cause a vacuum leak.
2 If you suspect that a vacuum leak exists at the bottom of the carburetor or throttle body, obtain a length of hose. Start the engine and
place one end of the hose next to your ear as you probe around the
base with the other end. You will hear a hissing sound if a leak exists
(be careful of hot or moving engine components when performing this
check).
3 Remove the air cleaner assembly, tagging each hose to be disconnected with a piece of numbered tape to make reassembly easier.
4 Locate the mounting nuts or bolts at the base of the carburetor
or throttle body. Decide what special tools or adapters will be necessary, if any, to tighten the fasteners.
5 Tighten the nuts to the specified torque. Don't overtighten them,
as the threads could strip.
6 If, after the nuts or bolts are properly tightened, a vacuum leak
still exists, the carburetor or throttle body must be removed and a new
gasket installed. See Chapter 4 for more information.
7 After tightening the fasteners, reinstall the air cleaner and return
all hoses to their original positions.
24 Throttle linkage inspection
1 Inspect the throttle linkage for damage and missing parts and for
binding and interference when the accelerator pedal is depressed.
2 Lubricate the various linkage pivot points with engine oil.
I
The Motor Manual Guy
Chapter 1 Tune-up and routine maintenance
1-22
25
26
Thermostatic air cleaner check
Refer to illustrations 25.3a and 25.3b
1 Some engines are equipped with a thermostatically controlled air
cleaner which draws air to the carburetor from different locations, depending on engine temperature.
2 This is a visual check. If access is limited, a small mirror may have
to be used.
3 Locate the air valve inside the air cleaner assembly. It's inside the
long snorkel of the air cleaner housing (see illustrations).
4 If there is a flexible air duct attached to the end of the snorkel,
leading to an area behind the grille, disconnect it at the snorkel. This
will enable you to look through the end of the snorkel and see the air
valve inside.
5 The check should be done when the engine is cold. Start the engine and look through the snorkel at the air valve, which should move
to a closed position. With the valve closed, air cannot enter through
the end of the snorkel, but instead enters the air cleaner through the
flexible duct attached to the exhaust manifold and the heat stove passage.
6 As the engine warms up to operating temperature, the air valve
should open to allow air through the snorkel end. Depending on outside temperature, this may take 10-to-15 minutes. To speed up this
check, you can reconnect the snorkel air duct, drive the vehicle until it
reaches normal operating temperature, then check to see if the air
valve is completely open.
7 If the thermostatically controlled air cleaner isn't operating properly, see Chapter 6 for more information.
Drivebelt check, adjustment and replacement
Refer to illustrations 26.3, 26.4a, 26.4b, 26.5a, 26.5b, 26.12a and
26.12b
1 The drivebelts, or V-belts as they are often called, are located at
the front of the engine and play an important role in the overall operation of the engine and accessories. Due to their function and material
makeup, the belts are prone to failure after a period of time and should
be inspected and adjusted periodically to prevent major engine damage.
2 The number of belts used on a particular vehicle depends on the
accessories installed. Drivebelts are used to turn the alternator, power
steering pump, water pump and air conditioning compressor. Depending on the pulley arrangement, more than one of these components
may be driven by a single belt. Later models are equipped with one
serpentine drivebelt that runs all engine accessories.
3 With the engine off, locate the drivebelts at the front of the engine.
Using your fingers (and a flashlight, if necessary), move along the belts
checking for cracks and separation of the belt plies. Also check for
fraying and glazing, which gives the belt a shiny appearance (see illustration). Both sides of each belt should be inspected, which means
you will have to twist the belt to check the underside. Check the pulleys for nicks, cracks, distortion and corrosion.
4 The tension of each V-belt is checked by pushing on it at a distance halfway between the pulleys. Push firmly and see how much the
belt moves (deflects) (see illustration). A rule of thumb is that if the
distance from pulley center-to-pulley center is between 7 and 11 inches, the belt should deflect 1/4-inch. If the belt travels between pul-
Thermostatic air cleaner for V6 engines and some four-cylinder engines (air
should close off the
valve shown open) - when the engine is cold, the air valve (I)
snorkel end (2), allowing warm air to flow through the flexible duct (3), which is
attached to the exhaust manifold and heat stove passage -when the engine is at
normal operating temperature, the air valve should be open, allowing cool air to flow
through the snorkel end (2)
,"· ._·
a
,·
· .. ,
. .J
BELT
SMALL
CRACKS
GREASE
STRAIGHT
~
J
II
r:. 1
.II!-..-,.
GLAZED
I
26.3
25.3b On inline six-cylinder engines, the
thermostatic air cleaner is located
towards the front of the driver's side of the
engine compartment you must put a
mirror in front of the radiator support to
view the air valve
,~
ALWAYS CHECK
the underside
of the belt.
Check the V-belt for signs of wear like these if it looks
worn, replace it
. ..
MAKE SURE RULER IS
PERPENDICULAR TO STRAIGHT EDGE
26.4a
Measuring drivebelt deflection with a straightedge
and ruler
The Motor Manual Guy
Chapter 1 Tune-up and routine maintenance
leys spaced 12-to-1 6 inches apart, the belt should deflect 112-inch.
The tension on serpentine belts can only be checked using a belt tension gauge, available at auto parts stores (see illustration).
5 If adjustment is needed, either to make the belt tighter or looser,
it's done by moving the belt-driven accessory on the bracket. On later
models with a serpentine belt, belt tension is adjusted at the power
steering pump (or idler pulley if not equipped with power steering) (see
illustration).
6 For each component there will be an adjusting bolt and a pivot
bolt. Both bolts must be loosened slightly to enable you to move the
component.
7 After the two bolts have been loosened, move the component
away from the engine to tighten the belt or toward the engine to
loosen the belt. Hold the accessory in position and check the belt tension. If it's correct, tighten the two bolts until just snug, then recheck
the tension. If the tension is all right, tighten the bolts.
8 It will often be necessary to use some sort of pry bar to move the
accessory while the belt is adjusted. If this must be done to gain the
proper leverage, be very careful not to damage the component being
moved or the part being pried against.
9 To replace a belt, follow the above procedures for drivebelt adjustment, but slip the belt off the pulleys and remove it. Since belts tend to
wear out more or less at the same time, it's a good idea to replace all
of them at the same time. Mark each belt and the corresponding pulley
grooves so the replacement belts can be installed properly.
10 Take the old belts with you when purchasing new ones in order to
make a direct comparison for length, width and design.
26.Sa To adjust the tension on a serpentine drivebelt, loosen
the bolt and locknut on the front of the power steering pump. . .
G{-i,,:,at===---
26.4b If you are able to borrow either a Nippondenso or
Burroughs belt tension gauge, this is how it's installed on the
belt - compare the reading on the scale with the specified
drivebelt tension
11 Adjust the belts as described earlier 1n this Section.
12 When replacing a serpentine drivebelt (used on later models),
make sure the new belt IS routed correctly or the water pump could
.
illustrations). Also, the belt
turn backwards, causing overheating (see
must completely engage the grooves in the pulleys.
26.Sb
. . . loosen the two bolts on the rear of the power
steering pump and turn the adjusting bolt
SERPENTINE
BELT
CRANKSHAFT
VIBRATION
DAMPER
ALTERNATOR
ALTERNATOR
Typical four-cylinder engine serpentine drivebelt routing
BURROUGHS
NIPPONDENSO
SERPENTINE
BELT
26.12a
1-23
26.12b
~) \
~
Typical sir-cylinder engine serpentine drivebelt routing
1
The Motor Manual Guy
1-24
27
Chapter 1
Tune-up and routine maintenance
Seatbelt check
\
SOLE-VAC VACUUM
ACTUATOR
1 Check the seatbelts, buckles, latch plates and guide loops for any
obvious damage or signs of wear.
2 Make sure the seatbelt reminder light comes on when the key is
turned on.
3 The seatbelts are designed t o lock up during a sudden stop or impact, yet allow free movement during normal driving. The retractors
should hold the belt against your chest while driving and rewind the
belt when the buckle is unlatched.
4 If any of the above checks reveal problems with the seatbelt
system, replace parts as necessary.
28
Neutral start switch check
Warning: During the following checks there is a chance that the vehicle
could lunge forward, possibly causing damage or injuries. Allow plent y
of room around the vehicle, apply the parking brake firmly and hold
down the regular brake pedal during the checks.
1 Automatic transmission equipped models have a Neutral start
switch which prevents the engine from starting unless the shift lever
is in Neutral or Park.
2 Try to start the vehicle in each gear. The engine should crank only
in Park or Neutral.
3 Make sure the steering column lock allows the key to go into the
Lock position only when the shift lever is in Park.
4 The ignition key should come out only in the Lock position.
5 Refer t o Chapter 7, Part B for further information on the Neutral
start switch.
29
Spare tire and jack check
1 Check the spare tire to make sure it's securely fastened so it cannot
come loose when the vehicle is in motion.
2 Make sure the jack and components are secured in place.
3 0 Idle speed check and adjustment (1984 through
1986 carburetor-equipped models)
Note: ldle speed check and adjustment are not routine maintenance
procedures on vehicles other than those identified in the heading above.
Refer to illustrations 30.7, 30. 1 l a and 30. l b
1 Engine idle speed is the speed at which the engine operates when
no throttle pedal pressure is applied. The idle speed is critical to the
30.1 1a On four-cylinder engines, adjust the idle speed
by turning the 114-inch nut (arrow) on the end of the
sole-vac vacuum actuator
30.7 Before checking the idle speed on four-cylinder engines,
disconnect the vacuum hose from the sole-vac vacuum actuator
performance of the engine itself, as well as many engine sub-systems.
2 A hand-held tachometer must be used when adjusting idle speed
to get an accurate reading. The exact hook-up for these meters varies
with the manufacturer, so follow the particular directions included.
3 Set the parking brake and block the wheels. Be sure the transmission is in Neutral (manual transmission) or Park (automatic
transmission).
4 Turn off the air conditioner (if equipped), the headlights and any
other accessories during this procedure.
5 Start the engine and allow it to reach normal operating temperature.
6 Shut off the engine
7 On four-cylinder models, disconnect and plug the vacuum hose
on the sole-vac vacuum actuator (see illustration).
8 On V 6 models, disconnect and plug the EGR vacuum hose at the
EGR valve and the purge control vacuum hose on the canister (see Sections 4 1 and 4 2 t o locate the EGR valve and canister)
9 On automatic transmission equipped vehicles, have an assistant
shift to Drive while keeping the brake pedal firmly depressed. Place
manual transmission equipped vehicles in Neutral.
1 0 Check the engine idle speed with the tachometer and compare it
t o the VECI label, which is located in the engine compartment, on the
driver's side of the firewall.
1 1 If the idle speed is not correct, turn the idle speed adjusting screw
or nut until the idle speed is correct (see illustrations).
1 2 After adiustment, shift the automatic transmission into Park and
turn the engine off.
30.1 1b On V 6 engines, turn the idle speed screw (It o adjust
the idle speed - on V 6 engines equipped with air conditioning.
unplug the electrical lead from the air conditioning compressor.
turn the air conditioning on, then open the throttle slightly t o allow
the idle speed adjustment screw on the solenoid (2) to extend.
Turn the screw t o adjust the idle speed (DO NOT touch 3 and 4)
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
31 Fuel filter replacement
Vehicles equipped with a V6 engine
Refer to illustrations 31.6 and 31.8
1 On these models, the fuel filter is located inside the fuel inlet nut
at the carburetor. It's made of either pleated paper or porous bronze
and cannot be cleaned or reused.
2 The job should be done with the engine cold (after sitting at least
three hours). The necessary tools include open-end wrenches to fit
the fuel line nuts. Flare nut wrenches (which wrap around the nut)
should be used if available. In addition, you must obtain the replacement
filter (make sure it's for your specific vehicle and engine) and some
clean rags.
3 Remove the air cleaner assembly (see Chapter 4).If vacuum hoses
must be disconnected, be sure to note their positions and/or tag them
to ensure they are reinstalled correctly,
4 Follow the fuel line from the fuel pump to the point where it enters
the carburetor. In most cases the fuel line will be metal all the way
from the fuel pump to the carburetor.
5 Place some rags under the fuel inlet fittings to catch spilled fuel
as the fittings are disconnected.
6 With the proper size wrench, hold the fuel inlet nut immediately
next to the carburetor body. Now loosen the fitting at the end of the
metal fuel line with a flare-nut wrench (if available). Make sure the fuel
inlet nut next to the carburetor is held securely while the fuel line is
disconnected (see illustration).
7 After the fuel line is disconnected, move it aside for better access
to the inlet nut. Don't crimp the fuel line.
8 Unscrew the fuel inlet nut, which was previously held steady. As
1-25
this fitting is drawn away from the carburetor body, be careful not to
lose the thin washer-type gasket on the nut or the spring, located behind
the fuel filter. Also pay close attention to how the filter is installed (see
illustration).
9 Compare the old filter with the new one t o make sure they're the
same length and design.
10 Reinstall the spring in the carburetor body.
1 1 Place the filter in position (a gasket is usually supplied with the
new filter) and tighten the nut. Make sure it's not cross-threaded.
Tighten it securely, but be careful not to overtighten it as the threads
can strip easily, causing fuel leaks, Reconnect the fuel line t o the fuel
inlet nut, being careful not t o cross-thread the nut. Use a back-up
wrench on the fuel inlet nut while tightening the fuel line fitting.
12 Start the engine and check carefully for leaks. If the fuel line fitting
leaks, disconnect it and check for stripped or damaged threads. If the
fuel line fitting has stripped threads, remove the entire line and have
a repair shop install a new fitting. If the threads look all right, purchase
some thread sealina taoe and wrao the threads with it. Inlet nut reoair
kits are available at most auto parts stores t o overcome leaking at'the
fuel inlet nut.
Vehicles equipped with a four- or inline
six-c ylinder engine
Refer to illustrations 3 1. 15 and 31. 16
13 These engines employ an in-line fuel filter. The filter is located on
the left side frame rail, near the fuel tank. On six-cylinder port fuel injected engines, the system is under pressure even when the engine
is off. Warning: On inline six-cylinder engines, the system must be
depressurized (see Chapter 4) before any work is performed.
14 With the engine cold, place a container, newspapers or rags under
the fuel filter.
15 Disconnect the fuel hoses and detach the filter from the frame (see
illustration).
16 Install the new filter by reversing the removal procedure. Make sure
the arrow or the word "OUT" on the filter points toward the engine,
not the fuel tank (see illustration). Tighten the screw clamps securely,
but not to the point where the rubber hose is badly distorted.
A
B
31.8 Carbureter mounted fuel filter details
31.6 Two wrenches are required to loosen the carburetor
fuel inlet line
31.15 To remove the inline fuel filter, unscrew the fuel
hose clamps and pull off the hoses, then remove the
securing strap bolt (arrows)
A Fuel inlet n u t
B Washer-type gasket
C Filter
D Spring
31.1 6 Make sure the word OUT on the fuel filter
faces the engine
1
The Motor Manual Guy
Chapter 1
1-26
32
Tune-up and routine maintenance
7
8
Air filter and PCV filter replacement
9
Refer to illustrations 32.2a, 32. 2b, 32.4 and 32.6
At the specified intervals, the air filter and (if equipped) PCV filter
1
should be replaced with new ones. The engine air cleaner also supplies
filtered air t o the PCV system.
2 The filter on carburetor-equipped models is located on top of the
carburetor and is replaced by unscrewing the wing nut from the top
of the filter housing, disconnecting the clips and lifting off the cover
(see illustration). On most fuel-injected models, the filter is located in
a housing in the engine compartment. It can be replaced after disengaging the clips holding the top plate in place (see illustration).
3 While the top plate is off, be careful not t o drop anything into the
carburetor, TBI or air cleaner assembly.
4 Lift the air filter element out (see illustration) and wipe out the inside
of the air cleaner housing with a clean rag.
5 Place the new filter in the air cleaner housing. Make sure it seats
properly in the bottom of the housing.
6 The PCV filter is also located inside the air cleaner housing on some
models (see illustration). Remove the cover and air filter as previously
described, then locate the PCV filter on the inside of the housing.
33
Remove the old filter.
Install the new PCV filter and the new air filter.
Install the cover and any hoses which were disconnected
Ignition timing check and adjustment (1984 through
1986 carburetor-equipped models)
Refer to illustrations 33.1 and 33.4
Note: Ignition timing check and adjustment are not required on vehicles other than those identified in the heading above. If the information in this Section differs from the Vehicle Emission Control
Information label (located on the driver's side of the firewall in the engine compartment of your vehicle), the label should be considered
correct.
1 The engine must be at normal operating temperature and the air
conditioner must be Off. Make sure the idle speed iscorrect (see Section 30). Some special tools will be required for this procedure (see
illustration).
COVER
ELEMENT
32.2a On carburetor-equipped models, remove the air
cleaner wing nut, disconnect the clips, lift the cover off
and remove the filter element
32.4
Hold the top plate up and lift the filter element out
of the housing (fuel-injected model shown)
32.2b On fuel-injected models, clips on the sides hold the
top plate of the air cleaner t o the housing - they can be
pried loose with a screwdriver
32.6
PCV filter (used on some carburetor-equipped models)
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
1-27
1
33.4 The ignition timing marks are located at the front of
the engine (four-cylinder shown)
33.1 Tools needed to check and adjust the ignition timing
Vacuum plugs - Vacuum hoses will, i n most cases,
have to be disconnected and plugged. Molded plugs
i n various shapes and sizes are available for this
2 Inductive pick-up timing light - Flashes a bright
concentrated beam o f light when the number one
spark plug fires. Connect the leads according
to the instructions supplied with the light
3 Distributor wrench
On some models, the hold-down
bolt for the distributor is difficult to reach and turn with
conventional wrenches or sockets. A special wrench like
this must be used
1
2 Apply the parking brake and block the wheels to prevent movement of the vehicle. The transmission must be in Park (automatic) or
Neutral (manual).
3 On four-cylinder engines, disconnect and plug the hose connected
to the vacuum advance unit on the distributor and unplug the three
wire connector to the vacuum input switches.
4 Locate the timing marks at the front of the engine (they should be
visible from above after the hood is opened) (see illustration). The
crankshaft pulley or vibration damper has a groove in it and a scale
with notches and numbers is either molded into or attached to the engine's timing cover. Clean the scale with solvent so the numbers are
visible.
5 Use chalk or white paint to mark the groove in the pulley/vibration
damper.
6 Highlight the notch or point on the scale that corresponds to the
ignition timing specification on the Vehicle Emission Control Information label.
7 Hook up the timing light, following the manufacturer's instructions
(an inductive pick-up timing light is preferred). Generally, the power
leads are attached to the battery terminals and the pick-up lead is attached to the number one spark plug wire. On four and six-cylinder
engines, the number one spark plug is the very front one. On the V6
engine, the number one spark plug is the front one on the passenger's
side of the engine. Caution: I f an inductive pick-up timing light isn't
available, don't puncture the spark plug wire to attach the timing light
pick-up lead. Instead, use an adapter between the spark plug and plug
wire. If the insulation on the plug wire is damaged, the secondary voltage will jump to ground at the damaged point and the engine will misfire.
8 Make sure the timing light wires are routed away from the drivebelts and fan, then start the engine.
9 Allow the idle speed to stabilize, then point the flashing timing light
at the timing marks - be very careful of moving engine components!
10 The mark on the pulley/vibration damper will appear stationary.
If it's aligned with the specified point on the scale, the ignition timing is
correct.
11 If the marks aren't aligned, adjustment is required. Loosen the distributor hold-down bolt and turn the distributor very slowly until the
marks are aligned. Since access to the bolt is tight, a special distributor wrench may be needed.
12 Tighten the bolt and recheck the timing.
13 Turn off the engine and remove the timing light (and adapter, if
used).
14 Reconnect any components which were disconnected.
34 Automatic transmission fluid and filter change
Refer to illustration 34. 10
1 A t the specified time intervals, the transmission fluid should be
drained and replaced. Since the fluid will remain hot long after driving,
perform this procedure only after the engine has cooled down completely.
2 Before beginning work, purchase the specified transmission fluid
(see Recornmendedlubricants and fluids at the front of this Chapter)
and a new filter.
3 Other tools necessary for this job include jackstands to support
the vehicle in a raised position, a drain pan capable of holding at least
eight pints, newspapers and clean rags.
4 Raise the vehicle and support it securely on jackstands.
5 With a drain pan in place, remove the front and side pan mounting bolts.
6 Loosen the rear pan bolts approximately one turn.
7 If the pan does not loosen and fluid does not begin to drain, carefully
pry the transmission pan loose with a putty knife.
8 Remove the remaining bolts, pan and gasket. Carefully clean the
gasket surface of the transmission to remove all traces of the old gasket
and sealant.
9 Drain the fluid from the transmission pan, clean it with solvent and
dry it with compressed air.
The Motor Manual Guy
Chapter 1
1-28
SCREWS
Tune-up and routine maintenance
FILTER
36.6a Remove the bolts from the lower edge of the cover, . . .
34.10 The automatic transmission fluid filter is held i n
place by three screws (three-speed transmission shown)
10 Remove the filter from the transmission valve body (see illustration).
11 Install a new filter.
12 Make sure the gasket surface on the transmission pan is clean,
then install a new gasket. Put the pan in place against the transmission
and, working around the pan, tighten each bolt a little at a time until
the final torque figure is reached.
13 Lower the vehicle and add the specified amount of automatic transmission fluid through the filler tube (Section 6).
1 4 With the transmission in Park and the parking brake set, run the
engine at a fast idle, but don't race it.
15 Move the gear selector through each range and back to Neutral,
Check the fluid level.
16 Check under the vehicle for leaks during the first few trips.
3 5 Manual transmission lubricant change
1 Raise the vehicle and support it securely on jackstands,
2 Move a drain pan, rags, newspapers and wrenches under the transmission.
3 Remove the transmission drain plug at the bottom of the case (see
illustration 16.1) and allow the oil t o drain into the pan.
4 After the oil has drained completely, reinstall the plug and tighten
it securely.
5 Remove the fill plug from the side of the transmission case. Using
a hand pump, syringe or funnel, fill the transmission with the correct
amount of the specified lubricant. Reinstall the fill plug and tighten it
securely.
6 Lower the vehicle.
7 Drive the vehicle for a short distance then check the drain and fill
plugs for leakage.
36.6b
...
then loosen the top bolts and let the lubricant
drain out
3 6 Differential lubricant change
Refer to illustrations 36.6a, 36.6b, 36.6c and 36.8
1 Some differentials can be drained by removing the drain plug, while
on others it's necessary to remove the cover plate on the differential
housing. As an alternative, a hand suction pump can be used t o remove
the differential lubricant through the filler hole. If the gasket is leaking
or there is no drain plug and a suction pump isn't available, be sure
to obtain a new gasket at the same time the gear lubricant is purchased.
2 Raise the vehicle and suoport it securelv, on ,iackstands. Move a
drain pan, rags, newspapers' and wrenches under the vehicle.
36.6c After the lubricant has completely drained, remove
the cover
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
1-29
1
36.8 Carefully scrape the old gasket or sealant material off
to ensure a clean surface for the new gasket t o seal against
3
Remove the fill plug from the differential.
4 If equipped with a drain plug, remove the plug and allow the differential lubricant to drain completely. After the lubricant has drained,
install the plug and tighten it securely.
5 If a suction pump is being used, insert the flexible hose. Work the
hose down to the bottom of the differential housing and pump the lubricant out.
6 If the differential is being drained by removing the cover, remove
the bolts on the lower half of the cover (see illustration). Loosen the
bolts on the upper half and use them to keep the cover loosely attached
(see illustration). Allow the lubricant to drain into the pan, then completely remove the cover (see illustration).
7 Using a lint-free rag, clean the inside of the cover and the accessible
areas of the differential housing. As this is done, check for chipped
gears and metal particles in the lubricant, indicating that the differential
should be more thoroughly inspected and/or repaired.
8 Thoroughly clean the gasket mating surfaces of the differential
housing and the cover plate. Use a gasket scraper or putty knife to
remove all traces of the old gasket or sealant (see illustration).
9 Apply a thin layer of RTV sealant to the cover flange and then press
a new gasket into position on the cover. Make sure the bolt holes align
properly.
1 0 Place the cover on the differential housing and install the bolts.
Tighten the bolts securely.
11 On all models, use a hand pump, syringe or funnel to fill the differential housing with the specified lubricant until it's level with the
bottom of the plug hole.
12 Install the filler plug and tighten it securely.
37 Transfer case lubricant change (4WD models)
1 Drive the vehicle for at least 15 minutes in stop and go traffic to
warm the lubricant in the case. Perform this warm-up procedure in
4WD. Use all gears, including Reverse, to ensure the lubricant is sufficiently warm to drain completely.
2 Raise the vehicle and support it securely on jackstands.
3 Remove the filler plug from the case (see illustration 18.1).
4 Remove the drain plug from the lower part of the case and allow
the old lubricant to drain completely.
5 Carefully clean and install the drain plug after the case is completely
drained. Tighten the plug t o the specified torque.
6 Fill the case with the specified lubricant until it is level with the
lower edge of the filler hole.
7 Install the filler plug and tighten it securely.
8 Drive the vehicle for a short distance and recheck the lubricant
level. In some instances a small amount of additional lubricant will have
t o be added.
38.1 Tools and materials needed for front wheel
bearing maintenance
-
1 Hammer
A common hammer will do just fine
2 Grease - High-temperature grease which is formulated
specially for front wheel bearings should be used
If you have a scrap piece of 2x4, i t can
3 Wood block
be used to dirve the new seeal into the hub
4 Needle-nose pliers - Used to straighten and remove
the cotter pin in the spindle
This is very important in this
5 Torque wrench
procedure; if the bearing is too tight, the wheel won't
turn freely - if i t is too loose, the wheel will 'wobble'
on the spindle. Either way, it could mean extensive
damage
6 Screwdriver - Used to remove the seal from the hub (a
long screwdriver would be preferred]
Needed to loosen the nut on the
7 Socket/breaker bar
spindle if it is extremely tight
8 Brush - Together with some clean solvent, this will be
used to remove old grease from the hub and spindle
-
-
-
38 Front wheel bearing check, repack and
adjustment 12WD models)
Refer to illustrations 38.1,38.6,38.7,38.8,38.1I and 38.15
1 In most cases the front wheel bearings will not need servicing until
the brake pads are changed. However, the bearings should be checked
whenever the front of the vehicle is raised for any reason. Several items,
including a torque wrench and special grease, are required for this procedure (see illustration).
2 With the vehicle securely supported on jackstands, spin each wheel
and check for noise, rolling resistance and free play.
3 Grasp the top of each tire with one hand and the bottom with the
other. Move the wheel in-and-out on the spindle. If there's any noticable
movement, the bearings should be checked and then repacked with
grease or replaced if necessary.
4 Remove the wheel.
5 Fabricate a wood block (1 -111 6 inch by 112-inch by 2-inches long)
which can be slid between the brake pads to keep them separated.
Remove the brake caliper (see Chapter 9) and hang it out of the way
on a piece of wire.
6 Pry the dust cap out of the hub using a screwdriver or hammer
The Motor Manual Guy
Chapter 1
1-30
38.6
Tune-up and routine maintenance
Dislodge the dust cap by working around the outer
edge with a screwdriver or hammer and chisel
and chisel (see illustration).
7 Straighten the bent ends of the cotter pin, then pull the cotter pin
out of the nut retainer (see illustration). Discard the cotter pin and use
a new one during reassembly.
8 Remove the nut retainer, adjustment nut and thrust washer from
the end of the spindle (see illustration).
9 Pull the rotorlhub assembly out slightly, then push i t back into its
original position. This should force the outer bearing off the spindle
enough so it can be removed.
10 Pull the rotor/hub assembly off the spindle.
1 1 Use a screwdriver to pry the grease seal out of the rear of the hub
(see illustration). As this is done, note how the seal is installed.
12 Remove the inner wheel bearing from the hub.
13 Use solvent to remove all traces of the old grease from the bearings, hub and spindle. A small brush may prove helpful; however make
sure no bristles from the brush embed themselves inside the bearing
rollers. Allow the parts to air dry.
14 Carefully inspect the bearings for cracks, heat discoloration, worn
rollers, etc. Check the bearing races inside the hub for wear and
damage. If the bearing races are defective, the rotor/hub assemblies
should be taken to a machine shop with the facilities to remove the
old races and press new ones in. Note that the bearings and races come
as matched sets and old bearings should never be installed on new
38.7
Remove the cotter pin and discard it - use a new
one when the hub is reinstalled
races.
15 Use high-temperature front wheel bearing grease to pack the bearings. Work the grease completely into the bearings, forcing it between
the rollers, cone and cage from the back side (see illustration).
1 6 Apply a thin coat of grease t o the spindle at the outer bearing seat,
inner bearing seat, shoulder and seal seat.
17 Put a small quantity of grease inboard of each bearing race inside
the hub. Using your finger, form a dam at these points to provide extra
grease availability and to keep thinned grease from flowing out of the
bearing.
18 Place the grease-packed inner bearing into the rear of the hub and
put a little more grease outboard of the bearing.
1 9 Place a new seal over the inner bearing and tap the seal evenly
into place with a hammer and block of wood until it's flush with the hub.
2 0 Carefully place the rotor/hub assembly onto the spindle and push
the grease-packed outer bearing into position.
21 Install the thrust washer and adjustment nut. Tighten the nut only
slightly (no more than 12 ft-lbs of torque).
2 2 Spin the hub in a forward direction to seat the bearings and remove
any grease or burrs which could cause excessive bearing play later.
2 3 Check to see that the tiahtness of the adiustment nut is still
proximately 12 ft-lbs.
2 4 Loosen the adjustment nut until it's just loose, no more.
THRUST
WASHER
GREASE
BEARING
SEAL
38.8
Front wheel hub and bearing components (2WD models)
NUT
RETAINER
ADJUSTMENT
NUT
exploded view
PIN
DUST
CAP
The Motor Manual Guy
Chapter 1
Tune-up and routine maintenance
1-31
1
38.1 1
Use a screwdriver to pry the grease seal from the
rear of the hub
38.1 5 Work the grease into each bearing from the largediameter side until grease oozes out the small-diameter side
25 Using your hand (not a wrench of any kind), tighten the nut until
it's snug. Install the nut retainer and a new cotter pin through the hole
in the spindle and nut retainer. If the nut slots don't line up, loosen
the nut slightly until they do. From the hand-tight position, the nut
should not be loosened more than one-half flat to install the cotter pin.
26 Bend the ends of the cotter pin until they're flat against the nut.
Cut off any extra length which could interfere with the dust cap.
27 Install the dust cap, tapping it into place with a hammer.
28 Place the brake caliper near the rotor and carefully remove the wood
spacer. Install the caliper (see Chapter 9).
29 Install the tire/wheel assembly on the hub and tighten the lug nuts.
30 Grasp the top and bottom of the tire and check the bearings in
the manner described earlier in this Section.
31 Lower the vehicle.
39
Cooling system servicing (draining, flushing and refilling)
Refer to illustrations 39.4a, 39.4b, 39.4c and 39.5
Warning: Antifreeze is a corrosive and poisonous solution, so be careful
not to spill any of the coolant mixture on the vehicle's paint or your
skin. If this happens, rinse immediately with plenty of clean water. Consult local authorities regarding proper disposal procedures for antifreeze
before draining the cooling system. In many areas, reclamation centers
have been established to collect used oil and coolant mixtures.
1 Periodically, the cooling system should be drained, flushed and
refilled to replenish the antifreeze mixture and prevent formation of
rust and corrosion, which da
can impair
the performance of the cooling
system and cause engine
mage. When the cooling system is serviced, all hoses and the radiator cap should be checked and replaced
if necessary.
2 Apply the parking brake and block the wheels. If the vehicle has
just been driven, wait several hours to allow the engine to cool down
before beginning this procedure.
39.4a
On Wagoneer models, remove the park/tum signal
light for access t o the radiator drain
\
39.4b
On models other than Wagoneer, first check the
bottom of the radiator for the drain fitting
If the radiator drain on non-Wagoneer models isn't
located on the bottom of the radiator, you'll have to remove
the grille (Chapter 11) for access t o the drain (arrow)
The Motor Manual Guy
Chapter 1 Tune-up and routine maintenance
1-32
2 With the engine idling at normal operating temperature, pull the
valve (with hose attached) or CCV hose from the rubber grommet in
the cover.
3 Place your finger over the valve or hose opening. If there's no
vacuum, check for a plugged hose, manifold port, or valve. Replace
any plugged or deteriorated hoses.
4 Turn off the engine and shake the PCV valve, listening for a rattle.
If the valve doesn't rattle, replace it with a new one.
PC V valve replacement
COOLANT
TEMPERATURE
SENSOR
DRAIN
PLUG
39.5 On four and inline six-cylinder engines, the block
drain plug is located on the driver's side of the engine
block, below the exhaust manifold; V 6 engines have t w o
block drain plugs at the lower rear of each side of the
engine block (inline six-cylinder engine shown)
3 Once the engine is completely cool, remove the radiator cap (fourcylinder and V6 engines) or coolant pressure bottle cap (inline sixcylinder engines).
4 Move a large container under the radiator drain to catch the coolant.
Attach a hose to the drain fitting to direct the coolant into the container, then open the drain fitting (seeillustrations) by turning it counterclockwise (a pair of pliers may be required to turn it).
5 After the coolant stops flowing out of the radiator, move the container under the engine block drain plug(s) (see illustration). Remove
the plug(s) and allow the coolant in the block to drain.
6 While the coolant is draining, check the condition of the radiator
hoses, heater hoses and clamps (refer to Section 9 if necessary).
7 Replace any damaged clamps or hoses.
8 Once the system is completely drained, flush the radiator with fresh
water from a garden hose until it runs clear at the drain. On inline sixcylinder engines, add the flush water through the coolant pressure bottle. The flushing action of the water will remove sediments from the
radiator but will not remove rust and scale from the engine and cooling
tube surfaces.
9 These deposits can be removed with a chemical cleaner. Follow
the procedure outlined in the manufacturer's instructions. If the radiator
is severely corroded, damaged or leaking, it should be removed (Chapter 3) and taken to a radiator repair shop.
1 0 Remove the overflow hose from the coolant recovery reservoir
(four-cylinder and V6 engines). Drain the reservoir and flush it with
clean water, then reconnect the hose.
11 Close and tighten the radiator drain. Install and tighten the block
drain plugs.
12 Place the heater temperature control in the maximum heat position.
13 On four-cylinder and V6 engines, slowly add new coolant (a 50/50
mixture of water and antifreeze) to the radiator until it's full. Add coolant
t o the reservoir up t o the lower mark. On inline six-cylinder engines,
add coolant to the pressure bottle until the level is at the top of the
post (see Section 9).
1 4 Leave the radiator or pressure bottle cap off and run the engine
in a well-ventilated area until the thermostat opens (coolant will begin
flowing through the radiator and the upper radiator hose will become
hot).
15 Turn the engine off and let it cool. Add more coolant mixture to
bring the level back up to the lip on the radiator filler neck or top of
the post Online six-cylinder engine).
16 Squeeze the upper radiator hose to expel air, then add more coolant
mixture if necessary. Replace the radiator cap.
17 Start the engine, allow it t o reach normal operating temperature
and check for leaks.
40 Positive Crankcase Ventilation (PCV) valve or Crankcase
Ventilation (CCVI hose check, cleaning and replacement
Refer to illustration 40. 11
Check
The PCV valve or CCV hose is located in the rocker arm cover.
5 To replace the valve, pull it from the end of the hose, noting its
installed position and direction.
6 When purchasing a replacement PCV valve, make sure it's for your
particular vehicle and engine size. Compare the old valve with the new
one t o make sure they're the same.
7 Push the valve into the end of the hose until it's seated.
8 Inspect the rubber grommet for damage and replace it with a new
one if necessary.
9 Push the PCV valve and hose securely into position.
CC V hose and orifice cleaning
1 0 Later models are equipped with a CCV system which performs the
same function as the PCV system but uses a rubber fitting with a
molded-in orifice which is pressed into a hole in the rocker arm cover.
The fitting is connected to the intake manifold by a plastic hose.
1 1 If there is no vacuum at the end of the hose (Step 3), turn off the
engine, remove the fitting and clean the hose with solvent, clean the
fitting orifice (see illustration) if it's plugged. If the fitting or hose are
cracked or deteriorated, replace them with new ones.
1 2 Install the fitting and hose securely in the rocker arm cover.
41 Evaporative emissions control system check
Refer to illustration 4 1.2
1 The function of the evaporative emissions control system is to draw
fuel vapors from the gas tank and fuel system, store them in a charcoal
canister and route them to the intake manifold during normal engine
operation.
2 The most common symptom of a fault in the evaporative emissions
system is a strong fuel odor in the engine compartment. If a fuel odor
is detected, inspect the charcoal canister, located in the engine compartment (see illustration). Check the canister and all hoses for damage
and deterioration.
3 The evaporative emissions control system is explained in more
detail in Chapter 6.
42 Exhaust Gas Recirculation (EGR) system check
Refer to illustration 42.2
1 The EGR valve is usually located on the intake manifold, adjacent
to the carburetor or TBI unit. Most of the time when a problem develops
in this emissions system, it's due t o a stuck or corroded EGR valve.
2 With the engine cold to prevent burns, push on the EGR valve diaphragm. Using moderate pressure, you should be able t o press the diaphragm in-and-out within the housing (see illustration).
3 If the diaphragm doesn't move or moves only with much effort,
replace the EGR valve with a new one. If in doubt about the condition
of the valve, compare the free movement of the valve with a new one.
4 Refer t o Chapter 6 for more information on the EGR system.
43
Spark plug replacement
Refer to illustrations 43.2, 43.5a, 43.5b, 43.6 and 43.10
1 Open the hood.
2 In most cases, the tools necessary for spark plug replacement in-
The Motor Manual Guy
Chapter 1
40.1 1 A paper clip can be used t o
clean the CCV system orifice
43.2
Tune-up and routine maintenance
41.2 The charcoal canister (arrow) is
located on the firewall i n the engine
compartment - check the hoses
connected to i t for damage
Tools required for changing spark plugs
Spark plug socket - This will have special padding
inside to protect the spark plug porcelain insulator
2 Torque wrench - Although not mandatory, use of
this tool is the best way to ensure that the plugs
are tightened properly
3 Ratchet - Standard hand tool to fit the plug socket
4 Extension - Depending on model and accessories,
you may need special extensions and universal joints
to reach one or more of the plugs
Spark plug gap gauge - This gauge for checking the
gap comes in a variety o f styles. Make sure the gap
for your engine is included
43.5a Spark plug manufacturers recommend using a wiretype gauge when checking the gap
if the wire does not
slide between the electrodes with a slight drag,
adjustment is required
1-33
42.2 Move the EGR valve diaphragm in
and out to make sure it isn't stuck
elude a spark plug socket which fits onto a ratchet (spark plug sockets
are padded inside to prevent damage to the porcelain insulators on the
new plugs), various extensions and a gap gauge to check and adjust
the gaps on the new plugs (see illustration). A special plug wire removal
tool is available for separating the wire boots from the spark plugs,
but it isn't absolutely necessary. A torque wrench should be used to
tighten the new plugs.
3 The best approach when replacing the spark plugs is to purchase
the new ones in advance, adjust them to the proper gap and replace
them one at a time. When buying the new spark plugs, be sure to obtain
the correct plug type for your particular engine. This information can
be found on the Vehicle Emission Controllnformation label located in
the engine compartment on the driver's side of the firewall and in the
factory owner's manual. If differences exist between the plug specified
on the emissions label and in the owner's manual, assume that the
emissions label is correct.
4 Allow the engine to cool completely before attempting to remove
any of the plugs. While you're waiting for the engine to cool, check
the new plugs for defects and adjust the gaps.
5 The gap is checked by inserting the proper thickness gauge between the electrodes at the tip of the plug (see illustration). The gap
between the electrodes should be the same as the one specified on
the Vehicle Emissions Control Information label. The wire should just
slide between the electrodes with a slight amount of drag. If the gap
is incorrect, use the adjuster on the gauge body to bend the curved
side electrode slightly until the proper gap is obtained (see illustration).
If the side electrode is not exactly over the center electrode, bend it
with the adjuster until it is. Check for cracks in the porcelain insulator
(if any are found, the plug should not be used).
6 With the engine cool, remove the spark plug wire from one spark
43.Sb To change the gap, bend the side electrode only.
as indicated by the arrows, and be very careful not
t o crack or chip the porcelain insulator surrounding
the center electrode
1
The Motor Manual Guy
1-34
Chapter 1
Tune-up and routine maintenance
plug. Pull only on the boot at the end of the wire - do not pull on the
wire. A plug wire removal tool should be used if available (see illustration).
7 If compressed air is available, use it to blow any dirt or foreign material away from the spark plug hole. A common bicycle pump will also
work. The idea here is to eliminate the possibility of debris falling into
the cylinder as the spark plug is removed.
8 Place the spark plug socket over the plug and remove it from the
engine by turning it in a counterclockwise direction.
9 Compare the spark plug t o those shown in the color photos on
page 1-35 to get an indication of the general running condition of the
engine.
10 Thread one of the new plugs into the hole until you can no longer
turn it with your fingers, then tighten it with a torque wrench (if available) or the ratchet. It might be a good idea to slip a short length of
rubber hose over the end of the plug to use as a tool to thread it into
place (see illustration). The hose will grip the plug well enough to turn
it, but will start to slip if the plug begins to cross-thread in the hole this will prevent damaged threads and the accompanying repair costs.
11 Before pushing the spark plug wire onto the end of the plug, inspect it following the procedures outlined in Section 44.
12 Attach the plug wire to the new spark plug, again using a twisting
motion on the boot until it's seated on the spark plug.
13 Repeat the procedure for the remaining spark plugs, replacing
them one at a time to prevent mixing up the spark plug wires.
any built-up dirt and grease. Once the wire is clean, check for holes,
burned areas, cracks and other damage. Don't bend the wire excessively or the conductor inside might break.
6 Disconnect the wire from the distributor cap. A retaining ring at
the top of the distributor may have t o be removed to free the wires.
Again, pull only on the rubber boot. Check for corrosion and a tight
fit in the same manner as the spark plug end. Reattach the wire to the
distributor cap.
7 Check the remaining spark plug wires one at a time, making sure
they are securely fastened at the distributor and the spark plug when
the check is complete.
8 If new spark plug wires are required, purchase a new set for your
specific engine model. Wire sets are available pre-cut, with the rubber
boots already installed. Remove and replace the wires one at a time
to avoid mix-ups in the firing order. The wire routing is extremely important, so be sure to note exactly how each wire is situated before
removing it.
--
45
Distributor cap and rotor check and replacement
Refer to illustrations 45.3 and 45.6
Note: It's common practice to install a new distributor cap and rotor
whenever new spark plug wires are installed.
Check
1
To gain access to the distributor cap, especially on a V6 engine,
it may be necessary to remove the air cleaner assembly (see Chapter 4).
((c
43.6
When removing the spark plug wires, pull only on
the boot and use a twistinglpulling motion
2 Loosen the distributor cap mounting screws (note that the screws
have a shoulder so they don't come completely out). On some models,
the cap is held in place with latches that look like screws - to release
them, push down with a screwdriver and turn them about 112-turn.
Pull up on the cap, with the wires attached, to separate it from the
distributor, then position it to one side.
3 The rotor is now visible on the end of the distributor shaft. Check
it carefully for cracks and carbon tracks. Make sure the center terminal
spring tension is adequate and look for corrosion and wear on the rotor
tip (see illustration). If in doubt about its condition, replace it with a
new one.
4 If replacement is required, detach the rotor from the shaft and install
a new one. On some models, the rotor is press fit on the shaft and
can be pried or pulled off. On other models, the rotor is attached to
the distributor shaft with t w o screws.
5 The rotor is indexed to the shaft so it can only be installed one
way. Press fit rotors have an internal key that must line up with a slot
in the end of the shaft (or vice versa). Rotors held in place with screws
have one square and one round peg on the underside that must fit into holes with the same shape. Apply a very thin coat of silicone dielectric compound to the rotor blade, if a new rotor is being installed.
6 Check the distributor cap for carbon tracks, cracks and other
INSUFFICIENT
SPRING
TENSION
43.10 A length of 3116-inch ID rubber hose will save time and
prevent damaged threads when installing the spark plugs
44
Spfirk plug wire check and replacement
1 The spark plug wires should be checked at the recommended intervals and whenever new spark plugs are installed in the engine.
2 The wires should be inspected one at a time t o prevent mixing up
the order, which is essential for proper engine operation.
3 Disconnect the plug wire from one spark plug. To do this, grab
the rubber boot, twist slightly and pull the wire free. Do not pull on
the wire itself, only on the rubber boot (see illustration 43.6).
4 Check inside the boot for corrosion, which will look like a white
crusty powder. Push the wire and boot back onto the end of the spark
plug. It should be a tight fit on the plug. If it isn't, remove the wire
and use a pair of pliers t o carefully crimp the metal connector inside
the boot until it fits securely on the end of the spark plug.
5 Using a clean rag, wipe the entire length of the wire to remove
\
ROTOR
TIP
CORRODED
EVIDENCE
OF
PHYSICAL
CONTACT
WITH
CAP
45.3 The ignition rotor should be checked for wear and
corrosion as indicated here (if i n doubt about its condition,
buy a new one)
The Motor Manual Guy
CARBON DEPOSITS
NORMAL
Symptoms: Dry sooty deposits
indicate a r1ich mixture or weak
uses misfiring,
hard
ignition. CaL..:,v.:,
,,11.:,1111,,
starting and hesitation.
Recommendation: Check for
a clogged air cleaner, high float
level, sticky choke and worn ignition points. Use a spark plug
with a longer core nose for
greater anti-fouling protection.
Symptoms: Brown to grayishtan color and slight electrode
wear. Correct heat range for
engine and operating conditions.
Recommendation: When new
spark plugs are installed, replace with plugs of the same
heat range.
OIL DEPOSITS
Symptoms: Light brown deposits encrusted on the side or
center electrodes or both. Derived from oil and/or fuel additives. Excessive amounts may
mask the spark, causing misfiring and hesitation during acceleration.
Recommendation: If exc essive deposits accumulate o ver
a short time or low mileage, install new valve guide seals to
prevent seepage of oil into the
combustion chambers. Also try
changing gasoline brands.
ASH DEPOSITS
Symptoms: Oily coating
caused by poor oil control. Oil
is leaking past worn valve
guides or piston rings into the
combustion chamber. Causes
hard starting, misfiring and
hesition.
Recommendation: Correct
the mechanical condition with
necessary repairs and install
new plugs.
TOO HOT
Symptoms: Blistered, white insulator, eroded electrode and
absence of deposits. Results in
shortened plug life.
Recommendation: Check for
the correct plug heat ran_ge,
over-advanced ignition timing,
lean fuel mixture, intake manifold vacuum leaks and sticking
valves. Check the coolant level
and make sure the r'adiator is
not clogged.
PREIGNITION
Symptoms: Melted electrodes.
Insulators are white, but may
be dirty due to misfiring or flying debris in the combustion
ch"amber. Can lead to engine
damage.
Recommendation:
,,
. . Check for
the correct plug heat range,
over-advanced ignition timing,
lean fuel mixture, clogged cooling system and lack of lubrication.
HIGH SPEED GLAZING
Symptoms: Insulator has
yellowish, glazed appearance.
Indicates that combustion
chamber temperatures have
risen suddenly during hard acceleration. Normal deposits
melt to form a conductive coating. Causes misfiring at high
speeds.
Recommendation: Install new
plugs. Consider using a colder
plug if driving habits warrant.
WORN
Symptoms: Rounded electrodes with a small amount of
deposits on the firing end. Normal color. Causes hard starting
in damp or cold weather and
poor fuel economy.
Recommendation: Replace
with new plugs of the same
heat range.
DETONATION
Symptoms: Insulators may be
cracked or chipped. Improper
gap setting techniques can
also result in a fractured insulator tip. Can lead to piston
damage.
Recommendation: Make sure
the fuel anti-knock values meet
engine requirements. Use care
when setting the gaps on new
plugs. Avoid lugging the engine.
SPLASHED DEPOSITS
Symptoms: After long periods
of misfiring, deposits can
loosen when normal combustion temperature is restored by
an overdue tune-up. At high
speeds, deposits flake off the
piston and are thrown against
the hot insulator, causing misfiring.
Recommendation: Replace
the plugs with new ones or
clean and reinstall the originals.
GAP BRIDGING
MECHANICAL DAMAGE
Symptoms:
-,---.-------- Combustion
_ --------·-·· deposits lodge between the electrodes. Heavy deposits accumulate and bridge the electrode gap. The plug ceases to
fire, resulting in a dead cylinder.
Recommendation: Locate the
faulty
·--··, plug
,,._,, and
-··- remove
·-···-·- the
... _deposits from between the electrodes.
Symptoms: May be caused by
a foreign object in the combustion chamber or the piston
striking an incorrect reach (too
long) plug. Causes a dead cylinder and could result in piston
damage.
Recommendation: Remove
the foreign object from the engine and/or install the correct
reach plug.
1
The Motor Manual Guy
Chapter 1
1-36
Tune-up and routine maintenance
damage. Closely examine the terminals on the inside of the cap for
excessive corrosion and damage (see illustration). Slight deposits are
normal. Again, if in doubt about the condition of the cap, replace it
with a new one. Be sure to apply a small dab of silicone lubricant to
each terminal before installing the cap. Also, make sure the carbon
brush (center terminal) is correctly installed in the cap
a wide gap
between the brush and rotor will result in rotor burn-through and/or
damage to the distributor cap.
Replacement
7
Separate the cap from the distributor and transfer the spark plug
BROKEN
TOWER
CHARRED OR
ERODED TERMINALS
CRACK
CARBONTRACK
CARBON TRACK
WORN OR
DAMAGED
ROTOR
BUTTON
45.6 Shown here are some of the common defects to
look for when inspecting the distributor cap (if in doubt
about its condition, install a new one)
46.3 The oxygen sensor (arrow) is screwed into the
exhaust pipe, just below where the pipe and exhaust
manifold join
wires, one at a time, to the new cap. Be very careful not t o mix up
the wires!
8 Reattach the cap to the distributor, then tighten the screws or
reposition the latches to hold it in place.
46
Oxygen sensor and emission maintenance timer
replacement (1988 and later 49-state models)
Refer to illustrations 46.3 and 46.8
Note: Special care must b e taken when handling the oxygen sensorit's very sensitive:
a) The oxygen sensor has a permanently attached pigtail and
connector, which should not be removed. Damage or removal
of the pigtail or connector can adversely affect sensor operation.
b) Grease , d1·rt and other contaminantsshould be keptawayfrom
the electrical connector and the louvered end of the sensor.
c) DO not usecleaning solventsof any kind on theoxygen sensor.
d) Do not drop or roughly handle the sensor.
1 The sensor is located in the exhaust manifold or exhaust pipe
and is accessible from under the vehicle.
2 Since the oxygen sensor may be difficult t o remove with the engine cold, begin by operating the engine until i t has warmed to at
least 120-degrees F (48-degrees C).
3 Disconnect the electrical wire from the oxygen sensor and carefully unscrew the oxygen sensor from the exhaust pipe (see illustration). Be advised that excessive force may damage the threads.
Inspect the oxygen sensor for damage.
4 A special anti-seize compound must be used on the threads of
the oxygen sensor to aid in future removal. New or service sensors
will have this compound already applied, but if for any reason an oxygen sensor is removed and then reinstalled, the threads must be
coated before reinstallation.
5 Install the sensor and tighten it securely.
6 Connect the electrical wire.
7 On these models an emission maintenance timer (mounted on
the dash panel, to the right of the steering column) activates the
emissions maintenance indicator light on the instrument panel when
the oxygen sensor is scheduled for replacement (approximately
82,500 miles). The timer cannot be reset and must be replaced or disconnected t o turn out the indicator light.
8 To replace the timer, remove the cruise control module (if
equipped). Unplug the electrical connector, remove the screws and
lower the timer from the instrument panel (see illustration). Installation is the reverse of removal.
46.8
Emissions maintenance timer installation details
J
The Motor Manual Guy
Chapter 2 Part A
Four-cylinder engine
Contents
Camshaft and bearings - removal, inspection
and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5
Cylinder compression check. . . . . . . . . . . . . . . . See Chapter 2D
Cylinder head - removal and installation . . . . . . . . . . . . . . .
9
Drivebelt check, adjustment and replacement . . .
See Chapter 1
Engine mounts - check and replacement . . . . . . . . . . . . . . . 2 0
Engine overhaul. . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 2D
Engine - removal and installation . . . . . . . . . . . See Chapter 2 D
Exhaust manifold - removal and installation . . . . . . . . . . . . .
8
Flywheel/driveplate - removal and installation . . . . . . . . . . . 1 8
Front crankshaft oil seal
replacement . . . . . . . . . . . . . . . . 1 2
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
Hydraulic lifters - removal, inspection and installation . . . . . 1 0
7
Intake manifold - removal and installation . . . . . . . . . . . . . .
Oil pan - removal and installation . . . . . . . . . . . . . . . . . . . . 1 6
Oil pump
removal and installation . . . . . . . . . . . . . . . . . . . 1 7
Rear main oil seal - replacement . . . . . . . . . . . . . . . . . . . . . 1 9
Repair operations possible with the engine in the vehicle . . . .
2
Rocker arm cover - removal and installation . . . . . . . . . . . .
4
Rocker arms and pushrods - removal, inspection
and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
See Chapter 1
Spark plug replacement . . . . . . . . . . . . . . . . . . .
Timing chain and sprockets
removal, inspection
and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
Timing chain cover - removal and installation . . . . . . . . . . . 1 3
3
Top Dead Center (TDC) for number one piston
locating. . .
Valve spring, retainer and seals
replacement . . . . . . . . . . .
6
Vibration damper - removal and installation . . . . . . . . . . . . . 1 1
See Chapter 3
Water pump - removal and installation . . . . . . .
Specifications
General
Displacement . . . . . . . . . . . . . . . .
Cylinder numbers (front-to-rear) . .
Firing order . . . . . . . . . . . . . . . . .
.......... .. ........
....................
. . .. ................
1 5 0 cu. in. ( 2 . 5 liters)
1-2-3-4
1-3-4-2
Camshaft
Lobe lift (intake and exhaust) . . . . . . . . . . . . . . . . . . . . . . . .
0.265
End play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
None
Journal-to-bearing (oil) clearance. . . . . . . . . . . . . . . . . . . . . .
0.001
Journal out-of-round limit . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.002
Fuel pump eccentric diameter . . . . . . . . . . . . . . . . . . . . . . . .
1.61 5
Journal diameter (journals numbered from front-to-rear of engine)
No. 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.029
No. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.019
.................. ............
No. 3 . . . . . . . .
2.009
No. 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.999
0000~
CYLINDER NUMBERS
in
t o 0.003 in
in
t o 1.625 in
to
to
to
to
2.030
2.020
2.010
2.000
in
in
in
in
00
00
C
FIRING ORDER
\
2A
The Motor Manual Guy
Chapter 2 Part A
2A-2
Four-cylinder engine
Torque specifications
Camshaft sprocket bolt
Crankshaft pulley-to-vibration damper bolts
Cylinder head bolts
1984 through 1987
Step 1
Step 2
Step 3
Bolt 8 only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
All other bolts
1988 on
Step 1
Step 2
Step 3
Bolt 8 only
All other bolts
Driveplate bolts
Step 1
Step2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust manifold nuts
Flywheel bolts
Step 1
Step2
Intake manifold-to-cylinder head bolts
Oil pan mounting bolts
114x20
5/16
X
18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump bolts
Short
Long
Rocker arm capscrews
Rocker arm cover-to-cylinder head bolts
With RTV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
With pre-cured permanent gasket
Tensioner bracket-to-block bolts
Timing chain cover-to-block
Bolts
Nuts
Vibration damper bolt (lubricated)
1
Ft-lbs (unless otherwise indicated)
80
20
25
50
75
85
22
45
100
110
40
Turn an additional 60°
23
50
Turn an additional 60°
23
7
11
10
17
19
55 in-lbs
4 4 in-lbs
14
5
16
80
General information
This Part of Chapter 2 is devoted to in-vehicle repair procedures for
the 2.5 liter four-cylinder engine. Information concerning engine
removal and installation, as well as engine block and cylinder head
overhaul, is in Part D of this Chapter.
The following repair procedures are based on the assumption that
the engine is installed in the vehicle. If the engine has been removed
from the vehicle and mounted on a stand, many of the steps included
in this Part of Chapter 2 will not apply.
The Specifications included in this Part of Chapter 2 apply only to
the engine and procedures in this Part. The Specifications necessary
for rebuilding the block and cylinder head are found in Part D.
2 Repair operations possible with the engine in the vehicle
Many major repair operations can be accomplished without removing
the engine from the vehicle.
Clean the engine compartment and the exterior of the engine with
some type of pressure washer before any work is done. A clean engine
will make the job easier and will help keep dirt out of the internal areas
of the engine.
Depending on the components involved, remove the engine cover
and, if necessary, the hood to improve access to the engine as repairs
are performed (refer to Chapter 11 if necessary).
If vacuum, exhaust, oil or coolant leaks develop, indicating a need
for gasket or seal replacement, the repairs can generally be made with
the engine in the vehicle. The intake and exhaust manifold gaskets,
oil pan gasket and cylinder head gasket are all accessible with the
engine in place.
Exterior engine components such as the intake and exhaust
manifolds, the oil pan (and the oil pump), the water pump, the starter
motor, the alternator, the distributor and the carburetor or fuel injection
components can be removed for repair with the engine in place.
Since the cvlinder head can be removed without .pulling the enaine.
valve component servicing can also be accomplished with the engine
in the vehicle.
In extreme cases caused by a lack of necessary equipment, repair
or replacement of piston rings, pistons, connecting rods and rod bearings is possible with the engine in the vehicle. However, this practice
is not recommended because of the cleaning and preparation work that
must be done to the components involved.
3
Top Dead Center (TDC) for number one piston
locating
Refer to illustrations 3.6 and 3.8
Note: The following procedure is based on the assumption that the
distributor is correctly installed. If you are trying to locate TDC to install the distributor correctly, piston position must be determined by
feeling for compression at the number one spark plug hole, then aligning
the ignition timing marks as described in step 8.
1 Top Dead Center (TDC) is the highest point in the cylinder that
each piston reaches as it travels up-and-down when the crankshaft
turns. Each piston reaches TDC on the compression stroke and again
on the exhaust stroke, but TDC generally refers to piston position on
the compression stroke.
2 Positioning the piston(s) at TDC is an essential part of many procedures such as rocker arm removal, camshaft and timing chain/
sprocket removal and distributor removal.
3 Before beginning this procedure, be sure to place the transmission
in Neutral and apply the parking brake or block the rear wheels. Also,
remove the spark plugs (see Chapter 1 and disable the ignition system
using one of the following methods:
a) On ignition systems with the ignition coil mounted separately
from the distributor, detach the coil wire from the center terminal
The Motor Manual Guy
Chapter 2 Part A Four-cylinder engine
3.6 Make a mark on the aluminum distributor body
directly below the number one spark plug wire terminal on
the distributor cap (arrow)
of the distributor cap and ground it on the block with a jumper
wire.
b) On ignition systems with the ignition coil in the distributor cap
(no center terminal in the distributor cap), unplug the BAT electrical connector from the coil (see Chapter 5).
4 In order to bring any piston to TDC, the crankshaft must be turned
using one of the methods outlined below. When looking at the front
of the engine, normal crankshaft rotation is clockwise.
a) The preferred method is to turn the crankshaft with a socket and
ratchet attached t o the bolt threaded into the front of the crankshaft.
b) A remote starter switch, which may save some time, can also
be used. Follow the instructions included with the switch. Once
the piston is close t o TDC, use a socket and ratchet, as described
in the previous paragraph.
c) If an assistant is available to turn the ignition switch to the Start
position in short bursts, you can get the piston close to TDC without a remote starter switch. Make sure your assistant is out of
the vehicle, away from the ignition switch, then use a socket
and ratchet (as described in Paragraph a) to complete the procedure.
5 Note the position of the terminal for the number one spark plug
wire on the distributor cap. If the terminal isn't marked, follow the plug
wire from the number one cylinder spark plug to the cap.
6 Use a felt-tip pen or chalk to make a mark on the distributor body
directly under the terminal (see illustration).
7 Detach the cap from the distributor and set it aside (see Chapter 1
if necessary).
8 Turn the crankshaft (see Paragraph 3 above) until the notch in the
crankshaft pulley is aligned with the 0 on the timing plate (located at
the front of the engine) (see illustration).
9 Look at the distributor rotor - it should be pointing directly at the
mark you made on the distributor body. If it is, go to Step 12.
1 0 If the rotor is 1 8 0 ° off, the number one piston is at TDC on the
exhaust stroke. Go to Step 1 1.
1 1 To get the piston to TDC on the compression stroke, turn the crankshaft one complete turn (360°) clockwise. The rotor should now be
pointing at the mark on the distributor. When the rotor is pointing at
the number one spark plug wire terminal in the distributor cap and the
ignition timing marks are aligned, the number one piston is at TDC on
the compression stroke.
1 2 After the number one piston has been positioned at TDC on the
compression stroke, TDC for any of the remaining pistons can be
located by turning the crankshaft and following the firing order. Mark
the remaining spark plug wire terminal locations on the distributor body
just like you did for the number one terminal, then number the marks
to correspond with the cylinder numbers. As you turn the crankshaft,
directly at one of the marks
the rotor will also turn. When it's
pointing.
~ylinder
on the distributor, the piston for that part1cu 1ar
is at TDC on
the compression stroke.
3.8
4
2A-3
Turn the crankshaft clockwise until the notch aligns
with the 0
Rocker arm cover - removal and installation
_________
,4.8a
and 4.8b
Refer to illustrations 4.3, 4.5, 4.6,
1 Disconnect the negative cable from the battery.
2 Remove the air cleaner (see Chapter 4).
3 Label and then remove all hoses and/or wires necessary to provide clearance for rocker arm cover removal (see illustration).
4 On carburetor equipped models, disconnect the fuel pipe at the
fuel pump and swivel the pipe to allow removal of the rocker arm cover.
Cap the open fuel fittings (see Chapter
4.3
Typical rocker arm cover - before removing, disconnect
the CCV vacuum and fresh air inlet hoses (arrows)
2A
The Motor Manual Guy
2A-4
Chapter 2 Part A
Four-cylinder engine
4.6 Remove the old sealant from the rocker arm cover
flange and the cylinder head with a gasket scraper, then
clean the mating surfaces with lacquer thinner or acetone
4.5 On 1 9 8 4 through 1986 models, carefully pry the
cover loose after breaking the seal with a putty knife or
razor blade
4.8b Make sure the sealant is applied to the INSIDE of the
bolt holes or oil will leak out around the bolt threads
4.8a On models using RTV sealant, apply a continuous
3116-inch diameter bead of the sealant (arrow) t o the
rocker arm cover flange
5 Remove the rocker arm cover retaining bolts and lift off the cover.
On 1984 through 1986 models, the cover may stick. Detach the cover
by breaking the seal with a putty knife or razor blade. Locations for
prying have been provided (see illustration). Caution: To avoid damaging the cover, do not pry up until the seal has been broken.
6 Prior t o installation, remove all traces of dirt, oil and old gasket
material from the cover and cylinder head with a scraper (see illustration). Clean the mating surfaces with lacquer thinner or acetone and
a clean rag.
7 Inspect the mating surface on the cover for damage and warpage.
Correct or replace as necessary.
8 On models which use RTV, apply a continuous 118-inch (3mm)
bead of sealant (Jeep Gasket-In-a-Tube or equivalent) to the cover
flange. Be sure the sealant is applied to the inside of the bolt holes
(see illustrations). Note: On models with plastic rocker arm covers,
RTV or a gasket may be used. On models equipped with an aluminum
rocker arm cover, RTV must be used. Later models use a pre-cured
reuseable gasket - install these without sealant.
9 Place the rocker arm cover on the cylinder head while the sealant
(if used) is still wet and install the mounting bolts. Tighten the bolts
a little at a time until the specified torque is reached.
10 Complete the installation procedure by reversing the removal procedure.
11 Start the engine and check for oil leaks.
5
Rocker arms and pushrods - removal, inspection
and installation
Refer to illustrations 5.3 and 5.4
Removal
1 Detach the rocker arm cover from the cylinder head, referring to
Section 4.
2 Beginning at the front of the cylinder head, loosen the rocker arm
bolts.
3 Remove the capscrews, bridges, pivots and rocker arms (see illustration). Store them in marked containers (they must be reinstalled in
their original locations).
4 Remove the pushrods and store them separately to make sure they
don't get mixed up during installation (see illustration).
Inspection
5 Check each rocker arm for wear, cracks and other damage,
especially where the pushrods and valve stems contact the rocker arm
faces.
6 Make sure the hole at the pushrod end of each rocker arm is open.
7 Check each rocker arm pivot area for wear, cracks and galling.
If the rocker arms are worn or damaged, replace them with new ones
and use new pivots as well.
The Motor Manual Guy
Chapter 2 Part A
Four-cylinder engine
2A-5
ROCKER ARM
5.3 Rocker arm mounts
exploded view
8
Inspect the pushrods for cracks and excessive wear at the ends.
Roll each pushrod across a piece of plate glass to see if it's bent (if
it wobbles, it's bent).
Ins tallation
9
Lubricate the lower ends of the pushrods with clean engine oil or
moly-base grease and install them in their original locations. Make sure
each pushrod seats completely in the lifter socket.
1 0 Apply moly-base grease to the ends of the valve stems and the
upper ends of the pushrods before positioning the rocker arms and installing the capscrews.
11 Set the rocker arms in place, then install the pivots, bridges and
capscrews. Apply moly-base grease to the pivots to prevent damage
to the mating surfaces before engine oil pressure builds up. Tighten
the bolts t o the specified torque.
12 Reinstall the rocker arm cover and run the engine. Check for oil
leaks and unusual valve train noises.
6
Valve spring, retainer and seals - replacement
Refer to illustrations 6.4, 6.9 and 6. 17
Note: Broken valve springs and defective valve stem seals can be
replaced without removing the cylinder heads. Two special tools and
a compressed air source are normally required to perform this operation,
so read through this Section carefully and rent or buy the tools before
beginning the job. If compressed air isn't available, a length of nylon
rope can be used to keep the valves from falling into the cylinder during
this procedure.
1
Remove the rocker arm cover referring to Section 4.
2 Remove the spark plug from the cylinder which has the defective
component. If all of the valve stem seals are being replaced, all of the
spark plugs should be removed.
3 Turn the crankshaft until the piston in the affected cylinder is at
top dead center on the compression stroke (refer to Section 3 for instructions). If you're replacing all of the valve stern seals, begin with
cylinder number one and work on the valves for one cylinder at a time.
Move from cylinder-to-cylinder following the firing order sequence (see
the Specifications).
4 Thread an adapter into the spark plug hole (see illustration) and
connect an air hose from a compressed air source to it. Most auto parts
stores can supply the air hose adapter. Note: Many cylinder compression gauges utilize a screw-in fitting that may work with your air hose
quick-disconnect fitting.
5.4 If more than one pushrod is being removed. store
them i n a perforated cardboard box t o prevent mixups
during installation - note the label indicating the front
of the engine
5 Remove the rocker arm and pivot for the valve with the defective
part and pull out the pushrod. If all of the valve stem seals are being
replaced, all of the rocker arms and pushrods should be removed (refer
to Section 5).
6 Apply compressed air to the cylinder. Warning: The piston may
be forced down by compressed air, causing the crankshaft to turn suddenly. If the wrench used when positioning the number one piston at
TDC is still attached to the bolt in the crankshaft nose, it could cause
damage or injury when the crankshaft moves.
7 The valves should be held in place by the air pressure. If the valve
faces or seats are in poor condition, leaks may prevent air pressure
from retaining the valves - refer to the alternative procedure below.
8 If you don't have access to compressed air, an alternative method
can be used. Position the piston at a point just before TDC on the compression stroke, then feed a long piece of nylon rope through the spark
plug hole until it fills the combustion chamber. Be sure to leave the
end of the rope hanging out of the engine so it can be removed easily.
Use a large ratchet and socket to rotate the crankshaft in the normal
direction of rotation until slight resistance is felt.
9 Stuff shop rags into the cylinder head holes above and below the
6.4 This is what the air hose adapter that threads into the
spark plug hole looks like - they're commonly available
from auto parts stores
The Motor Manual Guy
2A-6
Chapter 2 Part A
6.9 Once the spring is depressed, the keepers-can be
removed with a small magnet or needle-nose pliers (a
magnet is preferred t o prevent dropping the keepers)
valves to prevent parts and tools from falling into the engine, then use
a valve spring compressor to compress the spring. Remove the keepers
with small needle-nose pliers or a magnet (see illustration). Note: A
couple of different types of tools are available for compressing the valve
springs with the head in place. One type grips the lower spring coils
and presses on the retainer as the knob is turned, while the other type,
shown here, utilizes the rocker arm capscre w for leverage. Both types
work very well, although the lever type is usually less expensive.
10 Remove the spring retainer, oil shield and valve spring, then remove
the guide seal. Note: If airpressure fails to hold the valve in the closed
position during this operation, the valve face and/or seat is probably
damaged. If so, the cylinder head will have to be removed for additional repair operations.
11 Wrap a rubber band or tape around the top of the valve stem so
the valve won't fall into the combustion chamber, then release the air
pressure. Note: If a rope was used instead of air pressure, turn the
crankshaft slightly in the direction opposite normal rotation.
12 Inspect the valve stem for damage. Rotate the valve in the guide
and check the end for eccentric movement, which would indicate that
the valve is bent.
13 Move the valve up-and-down in the guide and make sure it doesn't
bind. If the valve stem binds, either the valve is bent or the guide is
damaged. In either case, the head will have t o be removed for repair.
1 4 Reapply air pressure to the cylinder to retain the valve in the closed
position, then remove the tape or rubber band from the valve stem.
If a rope was used instead of air pressure, rotate the crankshaft in the
normal direction of rotation until slight resistance is felt.
15 Lubricate the valve stem with engine oil and install a new guide seal.
1 6 Install the spring and shield in position over the valve.
17 Install the valve spring retainer. Compress the valve spring and
carefully position the keepers in the groove. Apply a small dab of grease
to the inside of each keeper to hold it in place (see illustration).
18 Remove the pressure from the spring tool and make sure the
keepers are seated.
19 Disconnect the air hose and remove the adapter from the spark
plug hole. If a rope was used in place of air pressure, pull it out of the
cylinder.
2 0 Refer to Section 5 and install the rocker arm(s) and pushrod(s).
21 Install the spark plug(s) and hook up the wire(s).
2 2 Refer t o Section 4 and install the rocker arm cover.
23 Start and run the engine, then check for oil leaks and unusual
sounds coming from the rocker arm cover area.
7
Four-cylinder engine
6.17 Apply a small dab of grease to the keepers before
installation - i t will hold them i n place on the valve stem
as the spring is released
2 Drain the cooling system (see Chapter 1 ).
3 Remove the carburetor or throttle body (see Chapter 4).
4 Label and then disconnect any wiring, hoses and contol cables still
connected to the intake manifold.
5 Unbolt the power steering pump (if equipped), and set it aside without disconnecting the hoses (see Chapter 10).
6 Disconnect the throttle valve (TV) linkage, if equipped with an automatic transmission (see Chapter 7).
7 Disconnect the EGR tube fom the intake manifold (see Chapter 6).
8 Remove the intake manifold bolts (see illustration). Pull the manifold
away from the engine slightly to disengage it from the dowel pins in
the cylinder head, then lift the manifold from the engine. If the manifold
sticks to the engine after all the bolts are removed, tap it with a softface hammer or a block of wood and a hammer while supporting the
manifold.
9 Thoroughly clean the mating surfaces, removing all traces of gasket
material (see illustration).
1 0 If the manifold is being replaced, transfer all fittings to the new one.
1 1 Position the replacement gasket on the cylinder head and install
the manifold.
12 lnstall the intake manifold bolts and tighten them (along with the
exhaust manifold nuts and EGR tube nut and bolts) in several stages,
following the sequence shown to the specified torque. (see illustration).
1 3 Reinstall the remaining parts in the reverse order of removal.
1 4 Run the engine and check for vacuum leaks and proper operation.
Intake manifold - removal and installation
Refer to illustrations 7.8, 7.9 and 7. 12
1 Disconnect the negative cable from the battery.
7 . 8 Remove the bolts ( I ) , pull the manifold away from the
engine slightly t o disengage it from the dowel pins (2),
then lift the manifold from the engine
The Motor Manual Guy
Chapter 2 Part A
Four-cylinder engine
2A-7
INTAKE
MANIFOLD
7.9 Remove the old intake manifold gasket with a scraper
- don't leave any material on the mating surfaces
7.12 Intake and exhaust manifold bolt tightening sequence
2A
9
8
Exhaust manifold - removal and installation
Refer to illustration 8.5
Warning: Allow the engine to cool to room temperaturebefore following
this procedure.
1 Remove the intake manifold (see Section 7).
2 Disconnect the EGR tube (see Chapter 6).
3 Remove the t w o nuts and bolts that secure the exhaust pipe to
the exhaust manifold. It may be necessary to apply penetrating oil t o
the threads.
4 Unplug the oxygen sensor wire connector (see Chapter 1, if
necessary ).
5 Remove the mounting nuts and spacers (see illustration) and detach
the exhaust manifold from the engine.
6 Clean the mating surfaces and, if the manifold is being replaced,
transfer the oxygen sensor to the new manifold.
7 Reinstall the exhaust manifold and finger tighten the nuts on the
end studs.
8 Reinstall the intake manifold (see Section 7) and tighten all mounting fasteners to the specified torque, following the sequence shown
in illustration 7.1 2. Reinstall the remaining components in the reverse
order of removal.
9 Run the engine and check for exhaust leaks.
Cylinder head - removal and installation
Refer to illustrations 9.9 and 9.15
Warning: Allow the engine to cool to room temperature before following
this procedure.
1 Remove the rocker arms and pushrods (see Section 5).
2 Remove the intake and exhaust manifolds (see Sections 7 and 8).
3 Remove the drivebelt(s) as described in Chapter 1.
4 Unbolt the power steering pump (if equipped) and set it aside
without disconnecting the hoses.
5 On air conditioned models, remove the bolt that secures the air
conditioning compressor/alternator bracket to the cylinder head, then
unbolt the compressor/alternator bracket from the engine. Set the compressor aside without disconnecting the hoses.
6 Label, then disconnect the wire from the coolant temperature sending unit on the cylinder head.
7 Label the spark plug wires and remove the spark plugs.
8 Remove the ten bolts that secure the cylinder head and lift it off
the engine. If the head is stuck to the engine block, it may be necessary
t o tap it with a soft-face hammer or a block of wood and a hammer
t o break the seal.
9 Stuff clean shop towels into the cylinders. Thoroughly clean the
gasket surfaces, removing all traces of gasket material. Run an appropriate sized tap into the bolt holes in the cylinder head and run a
die over the bolt threads (see illustration). Ensure all bolt holes are clean
and dry.
NUT
SPACER
8.5
MOUNTING ~"--.__/
NUT
Exhaust manifold mounting details
9.9 A die should be used t o remove sealant and corrosion
from the head bolt threads
The Motor Manual Guy
Chapter 2 Part A
2A-8
10
6
2
3
9
8
5
1
4
71--
9.15
Four-cylinder engine
Cylinder head bolt/nut tightening sequence
10 Inspect the cylinder head for cracks and check it for warpage. Refer
to Chapter 2, Part D, for cylinder head servicing procedures.
1 1 1984 through 1987 four-cylinder engines use different head
gaskets than 1988 and later models. The t w o types of gaskets are
NOT interchangeable and require different tightening torques.
10.5 Removing lifters with special tool J-21884
1984 through 1987 models
12 These engines use stamped steel gaskets. Apply an even coat of
Jeep/Eagle gasket sealing compound (or equivalent) to both sides of
the new gasket.
1988 and later models
13 These engines use a composition gasket. Install it dry (without any
sealing compound).
All models
14 lnstall the new gasket with the word Top on the cylinder head side.
Place the cylinder head on the engine.
15 Coat the threads of the stud bolt (no. 8 in the tightening sequence)
with Loctite Pipe Sealant with Teflon no. 592 (or equivalent). Install
the bolts and tighten them in the sequence shown (see illustration).
Tighten them in the steps and to the torque listed in the specifications.
Caution: During the final tightening step, bolt no. 8 is tightened to a
lower torque than the other bolts.
16 Install the remaining components in the reverse order of removal.
17 Change the oil and filter (see Chapter 1 ).
18 Refill the cooling system and run the engine, checking for leaks
and proper operation.
10 Hydraulic lifters
- removal,
inspection and installation
Removal
Refer to illustrations 10.5 and 10.6
1 A noisy valve lifter can be isolated when the engine is idling. Place
a length of hose or tubing on the rocker arm cover near the position
of each valve while listening at the other end. Or remove the rocker
arm cover and, with the engine idling, place a finger on each of the
valve spring retainers, one at a time. If a valve lifter is defective, it'll
be evident from the shock felt at the retainer as the valve opens.
2 The most likely cause of a noisy valve lifter is a piece of dirt trapped
between the plunger and the lifter body.
3 Remove the rocker arm cover (see Section 4).
4 Remove both rocker arms and both pushrods at the cylinder with
the noisy lifter (see Section 5).
5 Remove the lifters through the pushrod openings in the cylinder
head. A special removal tool is available (see illustration), but isn't
always necessary. On newer engines without a lot of varnish buildup,
lifters can often be removed with a magnet attached to a long handle.
6 Store the lifters in a clearly labelled box to insure their reinstallation
in the same lifter bores (see illustration).
10.6
If you're removing more than one lifter, keep them
i n order i n a clearly labelled box
Inspection
Refer to illustrations 10.Ba, 10.Bb, 10.Bc and 10.Bd
7 Clean the lifters with solvent and dry them thoroughly. Do this one
lifter at a time t o avoid mixing them up.
8 Check each lifter wall, pushrod seat and foot for scuffing, score
marks and uneven wear. Each lifter foot (the surface that rides on the
cam lobe) must be slightly convex, although this can be difficult to
determine by eye. If the base of the lifter is concave or rough (see illustrations), the lifters and camshaft must be replaced. If the lifter walls
are damaged or worn (which isn't very likely), inspect the lifter bores
i n the engine block as well. If the pushrod seats (see illustration) are
worn, check the pushrod ends.
9 If new lifters are being installed, a new camshaft must also be installed. If a new camshaft is installed, then use new lifters as well.
Never install used lifters unless the original camshaft is used and the
lifters can be installed in their original locations!
Installation
10 The used lifters must be installed in their original bores. Coat them
with moly-base grease or engine assembly lube.
1 1 Lubricate the bearing surfaces of the lifter bores with engine oil.
The Motor Manual Guy
Chapter 2 Part A
10.Sa If the bottom (foot) of any lifter is worn concave (shown
here), scratched or galled, replace the entire set with new lifters
10.Sc
Check the pushrod seat (arrow) in the top of each
lifter for wear
12 lnstall the lifter(s) in the lifter bore(s).
13 Install the pushrods and rocker arms (see Section 5). Caution: Make
sure that each pair of lifters is on the base circle of the camshaft; that
is, with both valves closed, before tightening the rocker arm bolts.
14 Tighten the rocker arm capscrews to the specified torque.
15 Install the rocker arm cover (Section 4).
Four-cylinder engine
2A-9
10.Sb The foot of each lifter should be slightly convex - the
side of another lifter can be used as a straightedge to check it;
if it appears flat, it's worn and must not be reused
10.Sd
If the lifters are pitted or rough, they shouldn't be reused
t o the vibration damper retaining bolt and immobilize the crankshaft
by wedging a large screwdriver between the bolt and the socket.
Remove the retaining bolt.
6 Remove the vibration damper. Use a puller if necessary (see illustration).
7 Refer to Section 12 for the front oil seal replacement procedure.
8 Apply a thin layer of moly-base grease t o the seal contact surface
of the vibration damper.
11 Vibration damper - removal and installation
Refer to illustration 11.6
1 Remove the cable from the negative battery terminal.
2 Remove the drivebelts (Chapter 1). Tag each belt as it's removed
to simplify reinstallation. If the vehicle is equipped with a fan shroud,
unscrew the mounting bolts and position the shroud out of the way.
3 Raise the vehicle and place it securely on jackstands.
4 If the vehicle is equipped with a manual transmission, apply the
parking brake and put the transmission in gear to prevent the crankshaft
from turning, then remove the crankshaft pulley bolts. If your vehicle
is equipped with an automatic transmission, it may be necessary to
remove the starter motor (Chapter 5) and immobilize the starter ring
gear with a large screwdriver while an assistant loosens the pulley bolts.
Note: On vehicles with serpentine belts, the pulle y and vibration damper
are combined as one piece - there are no pulley bolts to remove.
5 To loosen the vibration damper retaining bolt, install a bolt in one
of the pulley bolt holes. Attach a breaker bar, extension and socket
TOOL
11.6
T O remove the vibration damper, use special tool J-21791
or an equivalent puller which attaches t o the bolt holes
2A
The Motor Manual Guy
2A-10
Chapter 2 Part A
12.2 The front crankshaft seal can be removed with a seal
removal tool or a large screwdriver (V6 engine shown - fourcylinder similar)
Four-cylinder engine
12.6 Once the timing chain cover is removed, place it on a flat
surface and gently pry the old seal out with a large screwdriver
9 Slide the vibration damper onto the crankshaft. Note that the slot
in the hub must be aligned with the Woodruff key in the end of the
crankshaft. Once the key is aligned with the slot, tap the damper onto
the crankshaft with a soft-face hammer. The retaining bolt can also
be used to press the damper into position.
1 0 Tighten the vibration damper-to-crankshaft bolt to the specified
torque.
11 Install the crankshaft pulley (if equipped) on the hub and tighten
the bolts to the specified torque. Use Locktite on the bolt threads.
12 Install the drivebelt(s) (Chapter 1 and replace the fan shroud (if
equipped).
1 2 Front crankshaft oil seal - replacement
Note: The front crankshaft oil seal can be replaced with the timing chain
cover in place. However, due to the limited amount of room available,
you may conclude that the procedure would be easier if the cover were
removed from the engine first. If so, refer to Section 13 for the cover
removal and installation procedure.
Timing chain cover in place
Refer to illustration 12.2
1 Disconnect the negative battery cable from the battery, then
remove the vibration damper (see Section 1 1 ).
2 Note how the seal is installed - the new one must face the same
direction! Carefully pry the oil seal out of the cover with a seal puller
or a large screwdriver (see illustration). Be very careful not to distort
the cover or scratch the crankshaft!
3 Apply clean engine oil or multi-purpose grease to the outer edge
of the new seal, then install it in the cover with the lip (open end) facing
in. Drive the seal into place with a large socket and a hammer (if a
large socket isn't available, a piece of pipe will also work). Make sure
the seal enters the bore squarely and stop when the front face is flush
with the cover.
4 Install the vibration damper (see Section 11 ).
12.8a Clean the bore, then apply a small amount of oil to
the outer edge of the new seal and drive it squarely into
the opening with a large socket . . .
Timing chain cover removed
Refer to illustrations 12.6, 12.Ba and 12.Bb
5 Remove the timing chain cover as described in Section 13.
6 Using a large screwdriver, pry the old seal out of the cover (see
illustration). Be careful not to distort the cover or scratch the wall of
the seal bore. If the engine has accumulated a lot of miles, apply
penetrating oil to the seal-to-cover joint and allow it to soak in before
attempting to remove the seal.
7 Clean the bore to remove any old seal material and corrosion. Support the cover on a block of wood and position the new seal in the
12.8b
...
or a block of wood and a hammer
damage the seal in the process!
don't
The Motor Manual Guy
Chapter 2 Part A
bore with the lip (open end) of the seal facing in. A small amount of
oil applied to the outer edge of the new seal will make installation easier
- don't overdo it!
8 Drive the seal into the bore with a large socket and hammer until
it's completely seated (see illustration). Select a socket that's the same
outside diameter as the seal. A section of pipe or even a block of wood
can be used if a socket isn't available) (see illustration).
9 Reinstall the timing chain cover.
2A-11
Four-cylinder engine
with RTV sealant (Jeep Gasket-In-A-Tube or equivalent) and position
the seal onto the timing chain cover. Then apply a film of oil to the
seal-to-oil pan contact surface.
11 Position the timing chain cover on the engine block.
12 Install the vibration damper t o center the timing chain cover.
1 3 Install the cover-to-block nuts and bolts and the oil pan-to-cover
bolts and tighten them to the specified torque (see illustration).
1 4 Reinstall the remaining parts in the reverse order of removal.
1 5 Run the engine and check for oil leaks.
13 Timing chain cover - removal and installation
Refer to illustrations 13.6, 13.7 and 13.13
1 Remove the vibration damper (see Section 11 ).
2 Remove the fan and hub assembly (see Chapter 3).
3 Remove the air conditioning compressor (if equipped) and the alternator bracket assembly from the cylinder head and set it aside.
4 Remove the oil pan-to-timing chain cover bolts and the timing chain
cover-to-block bolts.
5 Separate the timing chain cover from the engine. Avoid damaging
the sealing surfaces; do not force tools between the cover and block.
6 Cut off the oil pan gasket end tabs flush with the front face of
the cylinder block and trim off the end seal tabs (see illustration).
7 Thoroughly clean the cover and all sealing surfaces, removing any
traces of gasket material. Drive the old oil seal out from the rear of
the timing chain cover and replace it with a new one (see Section 12).
Also replace the chain guide, if necessary (see illustration).
8 Apply sealing compound (Perfect Seal or equivalent) to both sides
of the new timing cover gasket and position the gasket on the engine
block.
9 Trim the end tabs off the new oil pan gaskets to correspond with
those cut off the original gasket. Attach the new end tabs to the oil
pan with cement.
10 Coat the timing chain cover-to-oil pan seal tab recesses generously
2A
13.6
Cut the end tabs (1) flush with the block and trim
the end seal tabs (2)
0
13.7 Inside view of timing chain cover
A Cutout for driving out oil seal
B Timing chain guide
13.13
Timing chain cover fastener locations
A
Bolt
B Nut
The Motor Manual Guy
Chapter 2 Part A
2A-12
Four-cylinder engine
1 4 Timing chain and sprockets
and installation
14.3
The timing marks on the sprockets (arrows) should
be lined up as shown
14.5
The timing chain and sprockets are removed and
installed as an assembly
- removal,
inspection
Refer to illustrations 14.3, 14.5, 14.7a, 14.7b and 14. 10
1 Set the number one piston at Top Dead Center (see Section 3).
2 Remove the timing chain cover (see Section 13).
3 Rein,· 'Ill the vibration damper bolt and rotate the crankshaft until
the zero timing mark on the crankshaft sprocket is lined up with the
timing mark on the camshaft sprocket (see illustration).
4 Slide the oil slinger off the crankshaft.
5 Remove the camshaft retaining bolt and slip both sprockets and
the chain off as an assembly (see illustration).
6 Clean the components and inspect for wear and damage. Excessive
chain slack and teeth that are deformed, chipped, pitted or discolored
call for replacement. Always replace the sprockets and chain as a set.
Inspect the tensioner for excessive wear and replace it, if necessary.
Note: The oil pan must be removed for timing chain tensioner replacement (see Section 17).
7 Turn the tensioner lever to the unlock position. Pull the tensioner
block toward the tensioner lever to compress the spring. Hold the block
and turn the tensioner lever to the lock position (see illustrations).
8 Install the crankshaft/camshaft sprockets and timing chain. Ensure
14.7a
The timing chain tensioner is located below the
timing chain
'INS
TENSIONER BLOCK
PULL FORWARD
14.7b
The timing chain tensioner is locked or unlocked
with the tensioner lever
14.10 With the camshaft sprocket timing mark at one
o'clock, count the chain pins between the t w o timing
marks - there must be 2 0 pins
The Motor Manual Guy
Chapter 2 Part A
the marks on the sprockets are still properly aligned (see illustration
14.3).
9 lnstall the camshaft sprocket retaining bolt and washer and tighten
to the specified torque.
10 To verify correct installation of the timing chain, turn the crankshaft
to place the camshaft sprocket timing mark at approximately the one
o'clock position. This positions the crankshaft timing mark where the
adjacent tooth meshes with the chain at the three o'clock position.
Count the number of chain pins between the timing marks of both
sprockets. There must be 2 0 pins (see illustration).
1 1 Release the tensioner by turning the lever to the unlock position.
Be sure the tensioner is released before installing the timing cover.
1 2 Install the oil slinger and the remaining parts in the reverse order
of removal. Refer to the appropriate sections for instructions.
15
Camshaft and bearings - removal, inspection and installation
Camshaft lobe lift check
Refer to illustration 15.3
1 To determine the extent of cam lobe wear, the lobe lift should be
checked prior to camshaft removal. Refer to Section 4 and remove the
rocker arm cover.
2 Position the number one piston at TDC on the compression stroke
(see Section 3).
3 Beginning with the number one cylinder valves, mount a dial indicator on the engine and position the plunger against the top surface
of the first rocker arm. The plunger should be directly above and in
line with the pushrod (see illustration).
4 Zero the dial indicator, then very slowly turn the crankshaft in the
normal direction of rotation until the indicator needle stops and begins
t o move in the opposite direction. The point at which it stops indicates
maximum cam lobe lift.
5 Record this figure for future reference, then reposition the piston
at TDC on the compression stroke.
6 Move the dial indicator to the remaining number one cylinder rocker
arm and repeat the check. Be sure t o record the results for each valve.
7 Repeat the check for the remaining valves. Since each piston must
be at TDC on the compression stroke for this procedure, work from
cylinder-to-cylinder following the firing order sequence.
8 After the check is complete, compare the results to the specifications. If camshaft lobe lift is less than specified, cam lobe wear has
occurred and a new camshaft should be installed.
Four-cylinder engine
2A-13
16 Remove the rocker arms and pushrods (see Section 5).
17 Remove the hydraulic lifters (see Section 10).
1 8 Remove the timing chain and sprockets (see Section 14). Note:
If the camshaft appears to have been rubbing against the timing chain
cover, examine the oilpressure relief holes in the rear cam journal and
ensure they are free of debris.
19 Install a bolt in the end of the camshaft to use as a handle. Carefully
slide the camshaft out of the block. Caution: TO avoid damage to the
camshaft bearings as the lobes pass over them, support the camshaft
near the block as it is withdrawn (see illustration).
Inspection
Refer to illustration 15.2 1
2 0 After the camshaft has been removed from the engine, cleaned
with solvent and dried, inspect the bearing journals for uneven wear,
pitting and evidence of seizure. If the journals are damaged, the bearing
inserts in the block are probably damaged also. Both the camshaft and
bearings will have t o be replaced.
21 If the bearing journals are in good condition, measure them with
a micrometer and record the measurements (see illustration). Measure
each journal at several locations around its circumference. If you ge
different measurements at different locations, the journal is out o
round.
2 2 Check the inside diameter of each camshaft bearing with a telescoping gauge and measure the gauge with a micrometer. Subtract
each cam journal diameter from the corresponding camshaft bearing
inside diameter to obtain the bearing oil clearance.
2 3 Compare the clearance for each bearing to the specifications. If
it is excessive, for any of the bearings, have new bearings installed
by an automotive machine shop.
Removal
Refer to illustration 15.19
9 Set the number one piston at Top Dead Center (see Section 3).
1 0 Disconnect the negative cable from the battery.
11 Remove the radiator (see Chapter 3).
12 On models equipped with air conditioning, unbolt the air conditioning compressor and set it aside without disconnecting the refrigerant
lines.
1 3 On carburetor equipped models, remove the fuel pump (see Chapter 4).
1 4 Remove the distributor (see Chapter 5).
15 If not removed already, detach the rocker arm cover (see Section
15.19
Support the camshaft near the block
15.3 When checking the camshaft lobe lift, the dial indicator
plunger must be positioned directly above the
15.21 The camshaft bearing journal diameters are checked
pinpoint excessive wear and out-of-round conditions
The Motor Manual Guy
2A-14
Chapter 2 Part A
Four-cylinder engine
SIDE RAIL
GASKETS
FRONT
SEAL
15.27 Be sure to apply moly-base grease or engine
assembly lube t o the cam lobes and bearing journals
before installing the camshaft
by an automotive machine shop.
2 4 lnspect the distributor drive gear for wear. Replace the camshaft
if the gear is worn.
25 lnspect the camshaft lobes (including the fuel pump lobe on carburetor equipped models) for heat discoloration, score marks, chipped
areas, pitting and uneven wear. If the lobes are in good condition and
if the lobe lift measurements are as specified, the camshaft can be
reused.
Bearing replacement
26 Camshaft bearing replacement requires special tools and expertise that place it outside the scope of the home mechanic. Take the
engine block (see Part D of this Chapter) to an automotive machine
shop to ensure the job is done correctly.
Installation
Refer to illustration 15.2 7
27 Lubricate the camshaft bearing journals and lobes with moly-base
grease or engine assembly lube (see illustration).
28 Slide the camshaft into the engine. Support the cam near the block
and be careful not to scrape or nick the bearings.
29 Temporarily place the camshaft sprocket onto the camshaft and
turn the camshaft until the timing mark is aligned with the centerline
of the crankshaft (see Section 14). Remove the sprocket.
3 0 Install the timing chain and sprockets and the remaining components in the reverse order of removal. Refer to the appropriate Sections for installation instructions. Note: If the original cam and lifters
are being reinstalled, be sure to install the lifters in their original locations. If a new camshaft was installed, be sure to install new lifters also.
31 Add coolant and change the oil and filter (see Chapter 1 ).
32 Start the engine and check the ignition timing. Check for leaks and
unusual noises.
16.8 Oil pan components - exploded view
the engine (see illustration).
9 Install the oil pan and tighten the mounting bolts to the specified
torque. Note that the 114-inch diameter and 5/1 6-inch diameter bolts
have different torques. Start at the center of the pan and work out
toward the ends in a spiral pattern.
10 lnstall the bellhousing dust cover and the starter, then reconnect
the exhaust pipe to the manifold and hanger brackets.
11 Lower the vehicle.
1 2 lnstall a new filter and add oil to the engine.
1 3 Reconnect the negative battery cable.
1 4 Start the engine and check for leaks.
17 Oil pump - removal and installation
Refer to illustration 17.2
1 Remove the oil pan (see Section 16).
2 Remove the t w o oil pump attaching bolts from the engine block
(see illustration).
GASKET
16 Oil pan - removal and installation
Refer to illustration 16.8
1 Disconnect the cable from the negative battery terminal.
2 Raise the vehicle and support it securely on jackstands.
3 Drain the engine oil and remove the oil filter (Chapter 1).
4 Disconnect the exhaust pipe at the manifold (see Section 8) and
hangers and tie the system aside.
5 Remove the starter (see Chapter 5) and the bellhousing dust cover.
6 Remove the bolts and detach the oil pan. Don't pry between the
block and pan or damage to the sealing surfaces may result and oil
leaks could develop. If the pan is stuck, dislodge it with a soft-face
hammer or a block of wood and a hammer.
7 Use a scraper t o remove all traces of sealant from the pan and
block, then clean the mating surfaces with lacquer thinner or acetone.
8 Using gasket adhesive, position new oil pan seals and gaskets on
STRAINER
ASSEMBLY
ATTACH! N G
BOLTS
17.2 Oil pump and components
The Motor Manual Guy
Chapter 2 Part A
3
Detach the oil pump and strainer assembly from the block.
4 If the pump is defective, replace it with a new one. If the engine
is being completely overhauled, install a new oil pump - don't reuse
the original or attempt to rebuild it.
5 To install the pump, turn the shaft so the gear tang mates with
the slot on the lower end of the distributor drive. The oil pump should
slide easily into place. If it doesn't, pull it off and turn the tang until
it's aligned with the distributor drive.
6 Install the pump attaching bolts. Tighten them to the specified
torque.
7 Reinstall the oil pan (see Section 16).
8 Add oil, run the engine and check for leaks.
18
Flywheel/driveplate -
removal and installation
Refer to illustrations 18.3, 18.4, 18.8 and 18.10
1 Raise the vehicle and support it securely on jackstands, then refer
to Chapter 7 and remove the transmission. If it's leaking, now would
be a very good time to replace the front pump seallo-ring (automatic
transmission only).
2 Remove the pressure plate and clutch disc (see Chapter 8) (manual
transmission equipped vehicles). Now is a good time to check/replace
18.3
Four-cylinder engine
2A-1 5
the clutch components and pilot bearing.
3 Use paint or a center punch to make alignment marks on the flywheel/driveplate and crankshaft to ensure correct alignment during
reinstallation (see illustration).
4 Remove the bolts that secure the flywheelldriveplate t o the crankshaft (see illustration). If the crankshaft turns, hold the flywheel with
a pry bar or wedge a screwdriver into the ring gear teeth to jam the
flywheel.
5 Remove the flywheelldriveplate from the crankshaft. Since the flywheel is fairly heavy, be sure to support it while removing the last bolt.
6 Clean the flywheel to remove grease and oil. lnspect the surface
for cracks, rivet grooves, burned areas and score marks. Light scoring
can be removed with emery cloth. Check for cracked and broken ring
gear teeth or a loose ring gear. Lay the flywheel on a flat surface and
use a straightedge t o check for warpage.
7 Clean and inspect the mating surfaces of the flywheelidriveplate
and the crankshaft. If the crankshaft rear seal is leaking, replace it before
reinstalling the flywheelldriveplate.
8 On models with a four-cylinder engine and an automatic transmission, the trigger wheel portion of the driveplate assembly provides the
timing signal for the fuel and ignition systems. If the trigger wheel
becomes damaged when removing/instail1ng the engine, transmission
or torque convertor, ignition performance will be affected. The general
result is either rough engine operation and backfire, or a no-start condition. Check for suspected trigger wheel damage as follows:
a) Check the trigger wheel radial runout on hte inner surface (A)
with a dial indicator (see illustration). Maximum allowable runout
is 0.016-inch (0.40 mm). Replace the driveplate assembly if
runout exceeds this figure.
b) Inspect the timing slot separators (Bl in the trigger wheel. Replace
the driveplate assembly if the separators are dented, distorted,
or cracked. Do not attempt t o repair the wheel as the results are
usually not satisfactory.
9 Position the flywheel/driveplate against the crankshaft. Be sure
to align the marks made during removal. Note that some engines have
an alignment dowel or staggered bolt holes to ensure correct installa-
Before removing the flywheel, index it t o the
crankshaft (arrow)
18.4 To prevent the flywheel from turning, hold a pry bar
against t w o bolts or wedge a large screwdriver into the
flywheel ring gear
18.8 The driveplate on a four-cylinder engine with an automatic
transmission has a trigger wheel - check the inner surface (Al
for excessive runout with a dial indicator - inspect the timing
slot separators (Bl for dents, distortion and cracks
2A
The Motor Manual Guy
2A-16
Chapter 2 Part A
tion. Before installing the bolts, apply thread locking compound t o the
threads.
10 Wedge a screwdriver into the ring gear teeth to keep the flywheel/
driveplate from turning as you tighten the bolts to the specified torque.
After the initial torque has been reached, turn each bolt an additional
as outlined in the specifications. Note: A 3/4-inch socket should
be marked every 60° on the outside (see illustration). After reaching
the specified torque, make a reference mark below one of the marks
on the socket. Turn the bolt until the next 60° mark is reached.
1 1 The remainder of installation is the reverse of the removal procedure.
18.10
Make marks every
on the socket t o indicate
how much you have turned the bolt
19.5 Carefully pry the oil seal out with a removal tool or a
screwdriver - don't nick or scratch the crankshaft or the
new seal will be damaged and leaks will develop
19.Sb If the special tool isn't available, tap around the
outer edge of the new seal with a hammer and punch t o
seat it squarely i n the bore
Four-cylinder engine
19
Rear main oil seal
- replacement
Refer to illustrations 9.5, 19. Ba, 19.Bb and 19.Bc
The rear main bearing oil seal can be replaced without removing
1
the oil pan or crankshaft.
2 Remove the transmission (see Chapter 7).
3 If equipped with a manual transmission, remove the pressure plate
and clutch disc (see Chapter 8).
4 Remove the flywheel or driveplate (see Section 18).
5 Using a seal removal tool or a large screwdriver, carefully pry the
seal out of the block (see illustration). Don't scratch or nick the crankshaft in the process.
6 Clean the bore in the block and the seal contact surface on the
crankshaft. Check the crankshaft surface for scratches and nicks that
could damage the new seal lip and cause oil leaks. If the crankshaft
is damaged, the only alternative is a new or different crankshaft.
7 Apply a light coat of engine oil or multi-purpose grease to the outer
edge of the new seal. Lubricate the seal lip with moly-base grease.
8 Press the new seal into place with special tool no. J36306 (if available) (see illustration). The seal lip must face toward the front of the
engine. If the special tool isn't available, carefully work the seal lip over
the end of the crankshaft and tap the seal in with a hammer and punch
until it's seated in the bore (see illustration). Note: A new rear main
oil seal (part number 8933004 143) with improved sealing characteristics is installed on engines built since December 8, 1986. The special
installation tool (J-36306) comes with a removable shim (see illustration). This shim is only used with the old style seal (part number
32416691. DO NOT use this shim with the new style seal.
19.8a
Installing the rear main oil seal with special
tool no. J39306
Alignment hole
in crankshaft
2 Dust lip
3 Dowel pin
4
5
6
7
Tool J-39306
Mandrel
Screws
Oil seal
19.Sc This special installation tool shim is ONLY used when
installing the old-style seal (part number 3241669) - w e
recommend using the new style seal
The Motor Manual Guy
Chapter 2 Part A
Four-cylinder engine
2A-17
9
Install the flywheel or driveplate.
1 0 If equipped with a manual transmission, reinstall the clutch disc
and pressure plate.
11 Reinstall the transmission as described in Chapter 7.
20 Engine mounts - check and replacement
Refer to illustration 20.8
1 Engine mounts seldom require attention, but broken or deteriorated
mounts should be replaced immediately or the added strain placed on
the driveline components may cause damage or wear.
Check
2 During the check, the engine must be raised slightly to remove
the weight from the mounts.
3 Raise the vehicle and support it securely on jackstands, then position a jack under the engine oil pan. Place a large block of wood between the jack head and the oil pan, then carefully raise the engine
just enough to take the weight off the mounts. Warning: DO NOT place
any part of your body under the engine when it's supported only by
a jack!
4 Check the mounts to see if the rubber is cracked, hardened or
separated from the metal plates. Sometimes the rubber will split right
down the center.
5 Check for relative movement between the mount plates and the
engine or frame (use a large screwdriver or pry bar to attempt to move
the mounts). If movement is noted, lower the engine and tighten the
mount fasteners.
6 Rubber preservative should be applied to the mounts to slow
deterioration.
20.8 Remove the through-bolt and nut
and mount bolt
then remove the mount nut (not visible in this photo) from
beneath the frame bracket (Cl
Replacement
7 Disconnect the negative battery cable from the battery, then raise
the vehicle and support it securely on jackstands (if not already done).
8 Loosen the nut on the through bolt and remove the bolt and nut
that secure the mount to the frame bracket (see illustration).
9 Raise the engine slightly with a jack or hoist (make sure the fan
doesn't hit the radiator or shroud). Remove the through bolt and nut
and detach the mount.
10 Installation is the reverse of removal. Use thread locking compound
on the mount bolts and be sure to tighten them securely.
2A
The Motor Manual Guy
Chapter 2 Part B
V6 engine
Contents
Oil pan - removal and installation
17
Oil pump
removal and installation . . . . . . . . . . . . . . . . . . . 18
Rear main oil seal - replacement
20
2
Repair operations possible w i t h the engine in the vehicle
Rocker arm covers
removal and installation
4
Rocker arms and pushrods - removal, inspection
and installation
5
Timing chain and sprockets
inspection, removal
and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Timing chain cover
removal and installation
13
3
Top Dead Center (TDC) for number one piston - locating . . .
Valve lash
adjustment
6
15
Valve lifters - removal, inspection and installation
Valve spring, retainer and seals - replacement
7
Vibration damper
removal and installation
11
Water pump - removal and installation
See Chapter 3
Air filter replacement.
See Chapter 1
Camshaft and bearings
removal, inspection
and installation
16
Compression check
See Chapter 2D
Crankshaft front oil seal - replacement
12
10
Cylinder heads
removal and installation.
See Chapter 1
Drivebelt check, adjustment and replacement . . .
Engine mounts - check and replacement
21
Engine oil and filter change
See Chapter 1
Engine oil level check
See Chapter 1
Engine overhaul
general information.
See Chapter 2D
Engine - removal and installation
See Chapter 2 D
Exhaust manifolds - removal and installation
9
19
Flywheel/driveplate - removal and installation
General information
I
Intake manifold
removal and installation
8
--
Specifications
General
171 cu.in. (2.8 liters)
Displacement
Cylinder numbers
Left bank (driver's side).
Right bank
Firing order
2-4-6
1-3-5
1-2-3-4-5-6
Camshaft
Lobe lift
Intake
Exhaust
Journal diameter
Journal-to-bearing (oil) clearance.
.....................
Torque specifications
Camshaft sprocket bolt
Camshaft cover (rear) bolts.
Crankshaft pulley-to-vibration damper bolts
Cylinder head bolts.
Exhaust manifold bolts
0.2311 in
0.2625 in
1.867 to 1.869 in
0.0010 to 0.0039 in
Ft-lbs (unless otherwise indicated)
15 t o 20
6 to 9
20 t o 30
70
25
Cylinder numbering
and direction distributor
rotor rotates (arrow)
The Motor Manual Guy
Chapter 2 Part B
Flywheel/driveplate bolts
Intake manifold-to-cylinder head bolts
Oil pan mounting bolts
6 x 1.0 m m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 x 1.25 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump-to-rear main bearing cap bolt
Rear main bearing cap bolts
Rockerarmstud
Rocker arm cover-to-cylinder head bolts
Withgasket
RTV only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tensioner bracket-to-engine block bolts
Timing chain cover bolts
8 X 1.25 r n m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 x 1.5 m m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing chain tensioner bolts
Vibration damper center bolt
45 to 55
23
6 to 9
14 to 22
26 to 35
70
43 to 49
43 t o 66 in-lbs
8
14
13 to 18
20 to 30
13 to 18
======~~~~~~~~~-·=·-· =·~-~mM
1
2B-1
V6 engine
General information
This Part of Chapter 2 is devoted to in-vehicle repair procedures for
the V6 engine. All information concerning engine removal and installation and engine block and cylinder head overhaul can be found in Part D
of this Chapter.
The following repair procedures are based on the assumption that
the engine is installed in the vehicle. If the engine has been removed
from the vehicle and mounted on a stand, many of the steps outlined
in this Part of Chapter 2 will not apply.
The specifications included in this Part of Chapter 2 apply only t o
the procedures contained in this Part. Part D of Chapter 2 contains the
specifications necessary for cylinder head and engine block rebuilding.
2 Repair operations possible with the engine in the vehicle
Many major repair operations can be accomplished without removing
the engine from the vehicle.
Clean the engine compartment and the exterior of the engine with
some type of degreaser before any work is done. It will make the job
easier and help keep dirt out of the internal areas of the engine.
Depending on the components involved, it may be helpful to remove
the hood to improve access to the engine as repairs are performed (refer
t o Chapter 1 1 if necessary). Cover the fenders t o prevent damage to
the paint. Special pads are available, but an old bedspread or blanket
will also work.
If vacuum, exhaust, oil or coolant leaks develop, indicating a need
for gasket or seal replacement, the repairs can generally be made with
the engine in the vehicle. The intake and exhaust manifold gaskets,
timing cover gasket, oil pan gasket, crankshaft oil seals and cylinder
head gasket are all accessible with the engine in place.
Exterior engine components, such as the intake and exhaust
manifolds, the oil pan (and the oil pump), the water pump, the starter
motor, the alternator, the distributor and the fuel system components
can be removed for repair with the engine in place.
Since the cylinder heads can be removed without pulling the engine,
valve component servicing can also be accomplished with the engine
in the vehicle. Replacement of the timing chain, sprockets and camshaft is also possible with the engine in the vehicle.
In extreme cases caused by a lack of necessary equipment, repair
or replacement of piston rings, pistons, connecting rods and rod bearings is possible with the engine in the vehicle. However, this practice
is not recommended because of the cleaning and preparation work that
must be done to the components involved.
w
a:
0
"w
ai
3.1
V 6 engine timing marks are located at the lower front
of the engine
use the firing order in the specifications in this Part of Chapter 2 for
the V6 engine.
4 Rocker arm covers - removal and installation
Refer to illustrations 4.5, 4.1I and 4.12
1 Disconnect the negative cable from the battery.
2 Remove the air cleaner assembly (see Chapter 4).
3 Label and then disconnect the wires and hoses which would interfere with removal of the rocker arm cover{s).
4 Label and then detach the spark plug wires and unclip the wire
retainers from the studs.
Right side
5 Remove the air injection diverter valve and the ignition coil (see
illustration).
3 Top Dead Center !TDC) for number one piston - locating
Refer to illustration 3. 1
See Chapter 2, Part A, Section 3 for this procedure. The timing mark
tab is attached t o the timing chain cover (see illustration). Be sure to
4.5 Remove the ignition coil (arrow) for access to the
right rocker arm cover
28
The Motor Manual Guy
Chapter 2 Part B V6 engine
4.11 Make sure the sealant is applied t o the inside of the
bolt holes or oil will leak out around the bolt threads
6
Disconnect the rubber hose from the air injection manifold (the air
injection manifold is the group of metal tubes which are screwed into
the exhaust manifold).
7 Disconnect the carburetor controls and remove them from the
bracket.
4.12 On models that use gaskets, apply RTV sealant t o
the joints between the head and intake manifold (arrows)
prior t o assembly
Left side
8
Disconnect the pipe bracket.
Both sides
9 Remove the six rocker arm cover attaching bolts and detach the
cover. Note that some of the bolts have posts attached to the ends
you'll have to use a deep socket to remove these. If the cover is
stuck, use a soft-face hammer or a block of wood and a hammer to
dislodge it. If the cover still will not come loose, pry on it carefully with
a putty knife, but do not distort the sealing flange surface.
10 Clean all dirt, oil and old gasket material from the sealing surfaces
with a scraper, solvent and clean rags.
1 1 On models that use RTV sealant in place of a gasket, apply a 3mm
(118-inch) bead of RTV to the flange of the cover. Be sure to apply
sealant on the inside of the bolt holes or oil will leak past the bolt threads
(see illustration). Caution: When applying RTV sealant, keep sealant
out o f the bolt holes as this couldresult in damage to the head casting.
12 On models that use gaskets, place a small amount of RTV sealant
on the seam area where the cylinder head and intake manifold meet
(see illustration) before installing the gasket.
13 Install the cover(s) while the RTV is still wet. Tighten the bolts
a little at a time to the specified torque.
1 4 Reinstall the remaining parts in the reverse order of removal.
15 Run the engine and check for oil leaks.
5
Rocker arms and pushrods
and installation
removal, inspection
Removal
Refer to illustration 5.4
1 Refer to Section 3 and detach the rocker arm cover(s) from the
cylinder head(s).
2 Beginning at the front of one cylinder head, loosen and remove
the rocker arm stud nuts. Store them separately in marked containers
to ensure that they will be reinstalled in their original locations. Note:
If the push rods are the only items being removed, loosen each n u t just
enough to allow the rocker arms to b e rotated to the side so the
pushrods can be lifted out.
3 Lift off the rocker arms and pivot balls and store them in the marked
containers with the nuts (they must be reinstalled in their original
locations).
4 Remove the pushrods and store them separately to make sure they
don't get mixed up during installation (see illustration).
5.4 When removing the pushrods, be sure t o store them
separately t o ensure reinstallation in their original positions
Inspection
5 Check each rocker arm for wear, cracks and other damage, especially where the pushrods and valve stems contact the rocker arm faces.
6 Make sure the hole at the pushrod end of each rocker arm is open.
7 Check each rocker arm pivot area for wear, cracks and galling. If
the rocker arms are worn or damaged, replace them with new ones
and use new pivot balls as well.
8 Inspect the pushrods for cracks and excessive wear at the ends.
Roll each pushrod across a piece of plate glass t o see if it's bent (if
it wobbles, it's bent).
Installation
Refer to illustrations 5.10 and 5.11
9 Lubricate the lower end of each pushrod with clean engine oil or
moly-base grease and install them in their original locations. Make sure
each pushrod seats completely in the lifter.
1 0 Apply moly-base grease to the ends of the valve stems and the
upper ends of the pushrods before positioning the rocker arms over
the studs (see illustration).
1 1 Set the rocker arms in place, then install the pivot balls and nuts.
Apply moly-base grease t o the pivot balls t o prevent damage to the
mating surfaces before engine oil pressure builds up (see illustration).
Be sure t o install each nut with the flat side against the pivot ball.
12 Adjust the valve lash (see Section 6).
1 3 Reinstall the rocker arm covers as described in Section 4.
The Motor Manual Guy
Chapter 2 Part B
1 Moly-base grease applied to the pivot balls will
ensure adequate lubrication until oil pressure builds up
when the engine is started
5.10 The ends of the
and the valve stems
should be lubricated with moly-base grease prior to
installation of the rocker arms
6
Valve lash - adjustment
Refer to illustration 6.5
Disconnect the cable from the negative battery terminal.
2 If the rocker arm covers are still on the engine, refer to Section 4
and remove them.
3 If the valve train components have been serviced just prior to this
procedure, make sure that the components are completely reassembled.
4 Rotate the crankshaft until the number one piston is at top dead
center (TDC) on the compression stroke (see Section 3). To make sure
you do not mix up the TDC positions of the number one and four pistons, place your fingers on the number one rocker arms as the timing
marks line up at the crankshaft pulley. If the rocker arms are not moving, the number one piston is at TDC. If they move as the timing marks
line up, the number four piston is at TDC.
5 Back off the rocker arm nut until play is felt at the pushrod, then
turn it back in until all play is removed. This can be determined by rotating the pushrod while tightening the nut. Just when drag is felt at
the pushrod, all lash has been removed (see illustration). Now turn
the nut an additional 314-turn.
6 Adjust the number one, five and six cylinder intake valves and the
number one, two and three cylinder exhaust valves, with the crankshaft
in this position, using the method just described.
7 Rotate the crankshaft until the number four piston is at TDC on the
compression stroke and adjust the number two, three and four cylinder intake valves and the number four, five and six cylinder exhaust
valves.
8 Refer to Section 4 and install the rocker arm covers.
6.5 Rotate the
and tighten the nut until you feel
resistance to rotation
V 6 engine
7
Valve spring, retainer and seals
- replacement
Refer to Chapter 2, Part A, Section 6 for this procedure. Remove
the rocker arm covers, rocker arms and pushrods; adjust the valve lash
following the procedures in this Part.
8 Intake manifold - removal and installation
Refer to illustrations 8. 7 1, 8.73, 8. 7, 8.20,8.23 and 8.25
1 Disconnect the negative cable from the battery.
2 Drain the coolant from the radiator (See Chapter 1 ).
3 Remove the carburetor (See Chapter 4).
4 Label and disconnect all wires and hoses connecting the intake
manifold to the vehicle.
5 Unbolt the air conditioning compressor and set it aside without
disconnecting the hoses (See Chapter 3).
6 Label and then disconnect the spark plug wires from the plugs,
then remove the distributor cap (See Chapter 1 ).
7 Remove the distributor (See Chapter 5).
8 Remove the EGR and diverter valves (See Chapter 6).
9 Remove the rocker arm covers (See Section 4).
10 Disconnect the upper radiator and heater hoses.
11 Unbolt the intake manifold and lift it off the engine. If it is stuck,
carefully pry against a protrusion of the manifold casting (see illustration). Do not pry between the gasket surfaces.
8.1I
Use a large screwdriver or pry bar to break the
manifold gasket seal
2B
The Motor Manual Guy
Chapter 2 Part B
2B-4
V6 engine
(
8.17
Use a 3116-inch diameter cutter to form a groove in
the manifold
rm e
UJJ
8.13 If a machined groove {arrow) is not present on the
underside of the rear of the manifold, scribe marks to
outline the area to be ground out
12 Thoroughly clean all sealing surfaces, removing all traces of oil and
old gasket material. Clean the intake manifold bolt holes in the cylinder
head by chasing them with a tap. Compressed air can be used to
remove the debris after chasing. Warning: Wear eye protection when
using compressed air.
13 Inspect the underside of the rear of the intake manifold t o see if
a machined groove (see illustration) is present. This groove was added
to later production models to improve oil sealing.
14 You may add this groove to early models yourself or take the manifold to a dealer or automotive machine shop to have it done.
15 Place tape over the intake manifold ports t o keep out metal chips.
16 Scribe marks on the intake manifold rear flange (see illustration
8.13) to outline the area to be ground out.
17 Obtain a die grinder or electric drill and a spherical cutter with a
3/1 6-inch diameter ball (see illustration). Warning: Wear eye protection!
1 8 Cut a groove 3116-inch wide by 1 /1 6 t o 118-inch deep. This provides a groove to hold RTV sealant when the manifold is installed on
the engine.
19 Thoroughly clean the intake manifold, removing all chips and tape.
2 0 Apply a 311 6-inch bead of RTV to each of the ridges between the
heads (see illustration).
21 Install new intake manifold gaskets, noting that they are marked
Right and Left. Be sure to install them as indicated.
22 Hold the gaskets in place by extending the RTV sealant bead up
8.23 The intake manifold gasket must be cut as shown before
installing it so the top can be positioned behind the pushrods
8.20
Apply RTV t o the block ridges between the heads (arrows)
114-inch onto the gasket ends.
23 The intake manifold gaskets will have t o be cut where indicated
t o position the tops behind the pushrods (see illustration). Cut only
those areas necessary to clear the pushrods.
2 4 Install the intake manifold on the engine and hand tighten the bolts.
Ensure the areas between the block ridges and intake manifold are completely sealed.
25 Working in the sequence shown (see illustration), tighten the
manifold bolts, in several steps, t o the specified torque.
26 Reinstall the remaining parts in the reverse order of removal.
27 Run the engine, adjust the ignition timing and check for oil and
vacuum leaks.
9 Exhaust manifolds - removal and installation
Refer to illustration 9.7
Warning: Allow the engine to cool to room temperature before performing this procedure.
8.25
Intake manifold bolt tightening sequence
The Motor Manual Guy
Chapter 2 Part B
V6 engine
9.7 Right-side exhaust manifold - exploded view
(left side similar)
10.13
bolts
Right side
1 Remove the cable from the negative battery terminal.
2 Raise the front of the vehicle and support it securely on jackstands.
Block the rear wheels to keep the vehicle from rolling.
3 Remove the bolts attaching the exhaust pipe to the exhaust manifold, then separate the pipe from the manifold.
4 Remove the jackstands and lower the vehicle.
5 Disconnect the air injection hose from the air injection manifold
(the air injection manifold is a group of metal tubes screwed into the
exhaust manifold).
6 Disconnect the spark plug wires from the spark plugs, labeling them
as they are disconnected to simplify installation.
7 Remove the exhaust manifold mounting bolts (see illustration) and
separate the manifold from the engine.
8 Installation is the reverse of the removal procedure. Before installing
the manifold, be sure to thoroughly clean the mating surfaces on the
manifold and cylinder head. Tighten the manifold !Dounting bolts to
the specified torque.
Left side
9 Disconnect the cable from the negative battery terminal.
10 Raise the front of the vehicle and place it securely on jackstands.
Block the rear wheels to keep the vehicle from rolling.
1 1 Remove the bolts attaching the exhaust pipe to the manifold, then
disconnect the pipe from the manifold.
12 Remove the four manifold mounting bolts accessible at the rear
of the manifold.
13 Remove the jackstands and lower the vehicle.
14 Remove the air cleaner assembly (see Chapter 4), labeling all hoses.
15 Disconnect the hoses leading to the air injection valve.
16 Disconnect and label any wires that will interfere with the removal
of the manifold.
17 Remove the power steering pump bracket from the cylinder head.
Loosen the pump adjusting bracket bolt and remove the pump drivebelt
from the pulley first. After removing the bracket from the cylinder head,
place the steering pump assembly aside, out of the way. Do not disconnect any hoses and be sure to keep the top of the pump up so that
no fluid spills.
18 Remove the remaining manifold bolts and separate the manifold
and heat shield from the engine.
19 Installation is the reverse of the removal procedure. Be sure to
thoroughly clean the cylinder head and manifold surfaces before installing the manifold. Tighten the bolts to the specified torque.
10
Cylinder heads
Tightening sequence for V6 engine cylinder head
loosen the bolts in a sequence opposite t o this
3 Locate the engine block drain plugs to the rear of the engine mounts
(the plug on the left side is just above the oil filter). Remove the plugs
and drain the block.
4 Disconnect the exhaust pipe from the exhaust manifold.
5 Unbolt and remove the oil dipstick tube assembly from the side
of the engine.
6 Remove the jackstands and lower the vehicle.
7 Note: Steps 8 through 1 are to be followed i f the head is to be
replaced with a n e w one. These Steps may be performed either before
or after the head has been removed. In the accompanying illustrations,
the procedures were performed before the head was removed.
8 Remove the exhaust manifold (refer to Section 9).
9 Remove the power steering pump bracket from the side of the
cylinder head.
1 0 Remove the air-conditioner compressor bracket from the front of
the cylinder head, if equipped.
11 Remove the coolant temperature sending unit from the front of
the cylinder head.
12 Loosen the rocker arm nuts enough to allow5).
removal of the pushrods, then remove the pushrods (see Section
1 3 Loosen the head bolts in a sequence opposite to the one used for
tightening them (see illustration).
14 Remove the cylinder head. To break the gasket seal, use a long
screwdriver or pry bar under the cast "ears" of the cylinder head. Be
sure not to damage the cylinder head sealing surface (see illustration).
15 If a new cylinder head is being installed, attach the components
previously removed from the old head. Before installing the cylinder
removal and installation
Refer to illustrations 10.13 and 10.14
Warning: Allow the engine to cool to room temperature before performing this procedure.
Left side head
1
2
Remove the intake manifold (refer to Section 8).
Raise the vehicle and place it securely on jackstands.
10.14 Be careful not t o damage the cylinder head sealing
surface when breaking the head loose with a pry bar or
large screwdriver
2B
The Motor Manual Guy
2B-6
Chapter 2 Part B
V6 engine
30 Loosen the rocker arm nuts sufficiently to allow removal of the
pushrods, then remove the pushrods (see Section 5).
31 Loosen the head bolts in a sequence opposite t o the one used for
tightening them (see illustration 10.13).
32 Remove the cylinder head. To break the gasket seal, insert a bar
into one of the exhaust ports, then carefully lift on the tool.
33 To install the head, refer to Steps 15 through 21.
11 Vibration damper - removal and installation
Refer to illustrations 1 1.5 and 1 1.8
1 Remove the bolts and separate the radiator shroud from the radiator.
2 Remove the cooling fan mounting bolts and lift off the cooling fan
and the radiator shroud.
3 Loosen the accessory drivebelt adjusting bolts as necessary, then
remove the drivebelts, tagging each one as it is removed t o simplify
reinstallation.
4 Remove the bolts from the crankshaft pulley (a screwdriver can
be used t o lock the starter ring gear on the flywheel so the crankshaft
won't rotate), then remove the pulley. Remove the damper center bolt.
5 Attach a puller to the damper. Draw the damper off the crankshaft,
being careful not to drop it as it breaks free. A common gear puller
should not be used to draw the damper off, as it may separate the
outer portion of the damper from the hub. Use only a puller which bolts
t o the hub (see illustration).
6 Before installing the damper, coat the front cover sealing surface
on the damper with moly-base grease.
7 Place the damper in position over the key on the crankshaft. Make
sure the damper keyway lines up with the key.
8 Using a damper installation tool (no. J-291 13 or equivalent), push
the damper onto the crankshaft. The special tool (see illustration)
11.5 Use a puller that applies force t o the center of the
be sure the center puller bolt doesn't damage the
hub
crankshaft threads
head, the gasket surfaces of both the head and the engine block must
be clean and free of nicks and scratches. Also, the threads in the block
and on the head bolts must be completely clean, as any dirt remaining
in the threads will affect bolt torque. You can clean the threads in the
block with a tap and the threads on the bolts with a die.
16 Place the gasket in position over the locating dowels, with the mark
This Side Up visible.
17 Position the cylinder head over the gasket.
18 Coat the cylinder head bolts with RTV sealant and install the bolts.
19 Tighten the bolts in the proper sequence (see illustration 10.13)
to the specified torque. Work up to the final torque in three steps.
20 Install the pushrods, making sure the lower ends are in the lifter
seats. Place the rocker arm ends over the pushrods and loosely install
the rocker arm nuts.
21 The remaining installation steps are the reverse of those for removal.
Before installing the rocker arm covers, adjust the valve lash (refer to
Section 6).
Right side head
22 Remove the intake manifold (refer to Section 8).
23 Raise the vehicle and place it securely on jackstands.
24 Locate the engine block drain plugs to the rear of the motor mounts
(the plug on the left side is just above the oil filter), remove the plugs
and drain the block.
25 Remove the t w o nuts and disconnect the exhaust pipe from the
exhaust manifold.
26 Remove the jackstands and lower the vehicle.
27 Remove the alternator from the alternator bracket, then remove
the bracket from the head.
28 Remove the lifting 'eye' from the rear of the head (necessary only
if the head is to be replaced with a new one).
29 Remove the exhaust manifold (if the head is to be replaced with
a new one) as described in Section 9.
11.8 A special tool is recommended t o install the
vibration damper
distributes the pressure evenly around the hub.
9 Remove the installation tool and install the damper retaining bolt.
Tighten the bolt to the specified torque.
10 To install the remaining components, reverse the removal procedure.
11 Adjust the drivebelts (refer to Chapter 1).
12 Crankshaft front oil seal - replacement
Refer to illustrations
2.3, 12.7 and 12.9
With front cover installed on engine
1 With the vibration damper removed (see Section 1 1 ), pry the old
seal out of the crankcase front cover with a large screwdriver. Be very
careful not to damage the surface of the crankshaft.
2 Place the new seal in position with the open end of the seal (seal
lip) toward the inside of the cover.
3 Drive the seal into the cover until it is seated. Tool J-23042-A (see
illustration) is recommended for this purpose. This tool is designed to
J-23042-A
12.3
A special tool is recommended for crankshaft front
seal installation
The Motor Manual Guy
Chapter 2 Part B
Driving the seal out of the front cover
V6 engine
12.9
28-7
Installing the new oil seal with a wood block
and a hammer
2B
13.6a
After the water pump (1) is removed, t w o bolts and t w o studs secure the timing chain cover (2) to the engine block
exert even pressure around the entire circumference of the seal as it
is hammered into place. A section of large-diameter pipe or a large
socket could also be used. Be careful not to distort the front cover.
4 Reinstall the remaining parts in the reverse order of removal.
With front cover removed from engine
5 This method is preferred, as the cover can be supported while the
old seal is removed and the new one is installed.
6 Remove the timing chain cover (refer to Section 13).
7 Using a large screwdriver, pry the old seal out of the bore in the
front of the cover. Alternatively, support the cover and drive the seal
out from the rear (see illustration). Be careful not to damage the cover.
8 With the front of the cover facing up, place the new seal in position
with the open end of the seal toward the inside of the cover.
9 Using a block of wood and hammer, drive the new seal into the
cover until it is completely seated (see illustration).
10 Install the timing chain cover by reversing the removal procedure
in Section 13.
13
.,
5
Disconnect the lower radiator hose at the front cover.
Remove the timing chain cover mounting bolts and separate the
cover from the engine (see illustrations).
7 Clean all oil, dirt and old gasket material from the sealing surfaces
of the cover and engine block. Replace the oil seal as described in Section 12.
8 Apply a continuous 3132-inch (2 mm) bead of anaerobic sealant
(Loctite 51 5 or equivalent) to both mating surfaces of the cover (except
6
Timing chain cover - removal and installation
Refer to illustrations 13. 6a, 13. 6b and 13.8
1 Remove the water pump as described in Chapter 3.
2 If equipped with air conditioning, remove the compressor from the
mounting bracket and secure it out of the way. Do n o t disconnect any
o f the air conditioning system hoses without having the system depressurized b y a dealer service department or air conditioning technician.
3 Remove the compressor mounting bracket.
4 Remove the vibration damper as described in Section 11.
...
and t w o bolts secure the timing chain cover
the front lip of the oil pan
The Motor Manual Guy
Chapter 2 Part B
28-8
Apply t w o types of sealant as shown
I
3132-inch bead of
anaerobic sealant
2
118-inch bead of RTV sealant
the mating surface where the cover engages the oil pan lip). Apply RTVtype sealant to the cover-to-oil pan area. Also apply anaerobic sealant
to the areas surrounding the coolant passages (see illustration).
9 Place the timing chain cover in position on the engine block and
install the mounting bolts. Tighten the bolts to the specified torque.
10 The remaining installation procedures are the reverse of removal.
1 4 Timing chain and sprockets - inspection, removal
and installation
Refer to illustrations 14.8, 14.9, 14.10 and 14.12
1
Disconnect the cable from the negative battery terminal.
2 Remove the vibration damper (refer to Section 11).
3 Remove the timing chain cover (refer to Section 13).
4 Before removing the chain and sprockets, visually inspect the teeth
on the sprockets for signs of wear and check the chain for looseness.
5 If either or both sprockets show any signs of wear (edges on the
teeth of the camshaft sprocket rounded, bright or blue areas on the
teeth of either sprocket, chipping, pitting,
they should be replaced
with new ones. Wear in these areas is very common. Failure t o replace
14.9
A screwdriver will hold the camshaft sprocket i n
place while loosening the mounting bolts
V 6 engine
14.8 The camshaft and crankshaft timing marks (arrows)
should be in exact alignment before removing the timing
sprockets and chain
a worn timing chain and sprockets may result in erratic engine performance, loss of power and lowered gas mileage.
6 If any one component (timing chain or either sprocket) requires
replacement, the other t w o components should be replaced as well.
7 If it is determined that the timing components require replacement,
proceed as follows.
8 Reinstall the vibration damper center bolt and use it to turn the
crankshaft clockwise until the marks on the camshaft and crankshaft
are in exact alignment (see illustration). At this point the number one
and four pistons will be at top dead center with the number four piston
in the firing position (verify by checking the position of the rotor in
the distributor, which should point t o the number four spark plug wire
terminal). Note: Do not attempt to remove either sprocket or the timing
chain until this is done and do not turn the crankshaft or camshaft after
the sprockets/chain are removed.
9 Remove the three camshaft sprocket retaining bolts (see illustration) and lift the camshaft sprocket and timing chain off the front of
the engine. It may be necessary to tap the sprocket with a soft-faced
hammer t o dislodge it.
10 If it is necessary to remove the crankshaft sprocket, it can be
withdrawn from the crankshaft with a special puller (see illustration).
1 1 Push the crankshaft sprocket onto the crankshaft using a bolt and
washer from the puller set.
14.10 A special puller will be needed t o remove the
crankshaft sprocket
The Motor Manual Guy
Chapter 2 Part B
V6 engine
2B-9
15.7a If the engine is factory equipped with oversize
lifters, the lifter boss will be marked with a dab of white
paint and will have 0.25 (mm) OS stamped on i t
14.12
Lubricating the thrust surface of the camshaft sprocket
2B
1 2 Lubricate the thrust (rear) surface of the camshaft sprocket with
moly-base grease or engine assembly lube (see illustration). Install the
timing chain over the camshaft sprocket with slack in the chain hanging down over the crankshaft sprocket.
13 With the timing marks aligned, slip the chain over the crankshaft
sprocket and then draw the camshaft sprocket into place with the three
retaining bolts. Do not hammer or attempt t o drive the camshaft
sprocket into place, as it could dislodge the welch plug at the rear of
the engine.
14 With the chain and both sprockets in place, check again to ensure
that the timing marks on the t w o sprockets are properly aligned. If not,
remove the camshaft sprocket and move it until the marks align.
15 Lubricate the chain with engine oil and install the remaining components in the reverse order of removal.
15
15.7b As the lifters are removed from the engine block,
they should be stored separately to ensure reinstallation in
their original positions
Valve lifters - removal, inspection and installation
Refer to illustrations 15.7a and 15. 7b
1 A noisy valve lifter can be isolated when the engine is idling. Hold
a mechanic's stethoscope or a length of hose near the position of each
valve while listening at the other end. Another method is to remove
the rocker arm cover and, with the engine idling, place a finger on each
of the valve spring retainers, one at a time. If a valve lifter is defective,
it will be evident from the shock felt at the retainer as the valve seats.
2 The most likely causes of noisy valve lifters are dirt trapped between the plunger and the lifter body or lack of oil flow, viscosity or
pressure. Before condemning the lifters, we recommend checking the
oil for fuel contamination, correct level, cleanliness and correct viscosity.
Removal
3 Remove the rocker arm cover(s) as described in Section 4.
4 Remove the intake manifold as described in Section 8.
5 Remove the rocker arms and pushrods (Section 5).
6 There are several ways to extract the lifters from the bores. A
special tool designed to grip and remove lifters is manufactured by many
tool companies and is widely available, but it may not be required in
every case. On newer engines without a lot of varnish buildup, the
lifters can often be removed with a small magnet or even with your
fingers. A machinist's scribe with a bent end can be used t o pull the
lifters out by positioning the point under the retainer ring in the top
of each lifter. Caution: Don't use pliers to remove the lifters unless
you intend to replace them with new ones (along with the camshaft).
The pliers may damage the precision machined and hardened lifters,
rendering them useless.
7 Before removing the lifters, arrange t o store them in a clearly labelled box to ensure that they're reinstalled in their original locations.
Note: Some engines may have both standard and 0.25 mm (0.0 10inch) oversize valve lifters installed at the factory. These are specially
marked (see illustration). Remove the lifters and store them where they
won't get dirty (see illustration).
Inspection and installation
8
Parts for valve lifters are not available separately. The work required to remove them from the engine again if cleaning is unsuccessful
outweighs any potential savings from repairing them. Refer to Chapter 2, Part A, for lifter and camshaft inspection procedures. If the lifters
are worn, they must be replaced with new ones and the camshaft must
be replaced as well - never install used lifters with a new camshaft
or new lifters with a used camshaft.
9 When reinstalling used lifters, make sure they're replaced in their
original bores. Soak new lifters in oil to remove trapped air. Coat all
lifters with moly-base grease or engine assembly lube prior t o installation.
1 0 The remaining installation steps are the reverse of removal.
11 Run the engine and check for oil leaks.
16
Camshaft and bearings - removal, inspection and installation
Refer to illustrations 16. 10, 16. 11 and 16. 13
Note: Before removing the camshaft, refer to Chapter 2, Part A (Section 15), and measure the lobe lift.
1 Remove the cable from the negative battery terminal.
2 Drain the oil from the crankcase (refer to Chapter 1 ).
3 Drain the coolant from the radiator (refer to Chapter 1 ).
4 Remove the radiator (refer to Chapter 3).
5 If equipped with air conditioning, remove the condenser (refer to
The Motor Manual Guy
2B-10
Chapter 2 Part B
16.10 Long bolts can be threaded into the camshaft bolt holes
to provide a handle for removal and installation of the
camshaft - support the cam near the block as it's withdrawn
Chapter 3 ) . Caution: The air conditioning system must be discharged
b y an air conditioning technician before the condenser can be removed.
Under no circumstances should this be attempted b y the home mechanic, as personal injury may result.
6 Remove the valve lifters (refer to Section 15).
7 Remove the timing chain cover (refer to Section 13).
8 Remove the fuel pump and pushrod (refer to Chapter 4).
9 Remove the timing chain and camshaft sprocket (refer to Section 14).
10 Install t w o long bolts in the camshaft bolt holes to be used as a
handle t o pull on and support the camshaft (see illustration).
11 Carefully draw the camshaft out of the engine block. Do this very
slowly t o avoid damage to the camshaft bearings as the lobes pass
over the bearing surfaces. Always support the camshaft with one hand
on the camshaft near the engine block and the other holding a wire
to support the camshaft from above (see illustration).
12 Refer to Chapter 2, Part A, for camshaft and bearing inspection
procedures.
13 Prior to installing the camshaft, coat each of the lobes and journals
with engine assembly lube or moly-base grease (see illustration).
14 Slide the camshaft into the engine block, again taking extra care
not to damage the bearings.
15 lnstall the camshaft sprocket and timing chain as described in Section 14.
16 Install the remaining components in the reverse order of removal
by referring to the appropriate Chapter or Section.
17 Adjust the valve lash (refer t o Section 6).
18 Have the air conditioning system (if equipped) evacuated and recharged.
17 Oil pan - removal and installation
Refer to illustrations 17.9, 17.1 and 17. 13
Note: The following procedure is based on the assumption that the
engine is in place i n the vehicle. If it's been removed, merely unbolt
the oil pan and detach it from the block.
V6 engine
16.11 A length of wire with a hook on it can be used t o
support the camshaft as you guide it out of the block
16.13 Be sure t o apply moly-base grease or engine
assembly lube to the cam lobes and bearing journals before
installing the camshaft
Installation
6 Clean the gasket sealing surfaces with lacquer thinner or acetone.
Make sure the bolt holes in the block are clean.
7 Due to oil leakage problems, the factory has provided updated procedures for oil pan sealing.
1984 models
8 Check the oil pan flanges for distortion, particularly around the bolt
holes and corners. If necessary, place the pan on a block of wood and
use a hammer to flatten and restore the gasket surface.
9 Apply RTV sealant at the rear cradle corners (see illustration) and
use oil pan gasket kit no. 8983500853 (or equivalent).
1 0 Install the oil pan as described in Steps 16 through 18.
Removal
1 Disconnect the negative battery cable from the battery, then refer
to Chapter 1 and drain the oil.
2 Refer t o Chapter 5 and remove the starter motor.
3 Separate the exhaust pipes from the manifolds.
4 Remove the oil pan mounting bolts.
5 Carefully separate the pan from the block. Don't pry between the
block and pan or damage to the sealing surfaces may result and oil
leaks could develop. You may have to turn the crankshaft slightly to
maneuver the front of the pan past the crankshaft counterweights.
17.9
On 1984 models, apply RTV sealant at the rear
cradle corners (arrows)
The Motor Manual Guy
Chapter 2 Part B
17.11
V6 engine
1
Using a straightedge, check for distortion at the
corners (arrows)
1 9 8 5 and 1986 models
1 1 Inspect the oil pan cradle corners for deformation using a straightedge across the cradle opening (see illustration).
12 Replace the oil pan with part no. 895301 1840 (or equivalent) if
any deformations are found during inspection.
1 3 These models have stand-offs (see illustration) on the oil pan side
rails for use with RTV sealant. To use a gasket with these pans, the
raised stand-offs must be filed or ground off.
1 4 Using oil pan gasket kit no. 8983500853 (or equivalent), place
the cradle seal into the groove in the rear main bearing cap. Apply a
small amount of RTV sealant to the corners of the seal where it contacts
the block.
15 Using gasket sealing compound. position the oil pan gasket on the
oil pan side rails.
17.13
The raised stand-offs (arrows) must be filed or
ground off before a gasket can be used
All models
16 Carefully position the pan against the block and install the bolts
finger tight. Tighten the bolts in three steps t o the specified torque.
Note that there are t w o bolt sizes which require different torques. Start
at the center of the pan and work out toward the ends in a spiral pattern.
17 The remaining steps are the reverse of removal. Caution: Don't
forget to refill the engine with oil before starting it (see Chapter 1).
18 Start the engine and check carefully for oil leaks at the oil pan.
18 Oil pump - removal and installation
Refer to illustration 18.2
1 Remove the oil pan (refer t o Section 17).
2 Remove the pump-to-rear main bearing cap bolt (see illustration)
and separate the pump and extension shaft from the engine.
3 To install the pump, move it into position and align the top end
of the hexagonal extension shaft with the hexagonal socket in the lower
end of the distributor drive gear. The distributor drives the oil pump,
so it is essential that this alignment is correct.
4 Install the oil pump-to-rear main bearing cap bolt and tighten it to
the specified torque.
5 Reinstall the oil pan.
19 Flywheel/driveplate - removal and installation
Refer t o Chapter 2, Part A, Section 2 0 for this procedure. Be sure
to use the torque specifications in this Part of Chapter 2 for the V6
engine.
20
Rear main oil seal
replacement (engine i n vehicle)
Identifying the seal type
V6 engines covered by this manual may be equipped with four types
of rear main oil seals. To avoid unnecessary work, it is important to
determine which type of seal your vehicle has before attempting
replacement.
18.2
Remove the oil pump-to-rear main bearing cap bolt
Most 1984 models have two-piece neoprene or rope-type seals. You
may service these seals without removing the crankshaft. Some 1984
models have been updated with a new design one-piece neoprene seal
which fits in the same groove as the old type seal it replaces. This type
is less prone to leaking, but the crankshaft must be removed to replace
it.
To determine which type seal you have on 1984 models, remove
the oil pan and rear main bearing cap. If you have a two-piece oil seal
(the lower portion comes off with the cap), follow the procedure outlined here. If you have an updated one-piece seal, the engine and crankshaft must be removed. Follow the procedures outlined in Section 23
of Part D of this Chapter.
On 1985 and later models, check for an oval cast on the left rear
surface of the engine block next to the transmission bellhousing. This
signifies the engine has a one-piece seal which may be accessed by
removing the flyw h ee 1/driveplate.
1984 models with rope-type seals
Refer to illustrations 20.3 and 20.7
Note: Special tools, as noted in the Steps which follow, are required
for this procedure. They are available from your dealer or may in some
cases be rented from an auto parts store or tool rental shop.
1 Although the crankshaft must be removed to install a new seal,
the upper portion of the seal can be repaired with the crankshaft in place.
2 Remove the oil pan and oil pump (Sections 17 and 181.
The Motor Manual Guy
2B-1 2
20.3
Chapter 2 Part B
Using a packing tool to pack the old rear main oil
seal into the groove - rope-type seal engines
V6 engine
20.7 Using guide tools t o install short pieces of seal cut
from the old main seal in the upper seal groove - ropetype seal engines
•
,
FLYWHEEL SIDEt
FRON T ENGINE
DUST LIP
APPLY GASKET SEALING
COMPOUND TO THIS AREA
END VIEW OF SEAL
20.20 A very thin coat of RTV sealant should be applied
to the area shown on two-piece neoprene seals
20.17
Tap i n one side of the seal and pull the seal out
from the other side with pliers
3 Using tool J-291 14-2, drive the old seal gently back into the
groove, packing it tight (see illustration). It will pack in t o a depth of
1 /4 to 314-inch.
4 Repeat the procedure on the other end of the seal.
5 Measure the amount that the seal was driven up into the groove
on one side and add 1 /1 6-inch. Remove the old seal from the main
bearing cap. Use the main bearing cap as a fixture and cut off a piece
of the old seal to the predetermined length. Repeat this process for
the other side.
6 Install the guide tool J-291 14-1 on the block.
7 Using the packing tool J-29114-2, work the short pieces of the
previously cut seal into the guide tool J-29114-1 and pack them into
the block groove on each side (see illustration). The guide and packing
tools have been machined to provide a built-in stop. Use of oil on the
seal pieces will ease installation.
8 Remove the guide tool.
9 Install a new seal in the main bearing cap.
10 Apply a thin, even coat of anaerobic-type gasket sealant to the
areas of the rear main bearing cap indicated in the illustration in Chapter 2, Part D (Section 23). Caution: Do notget any sealant on the bearing or seal faces.
11 Tighten the rear main bearing cap bolts to the specified torque.
12 Install the oil pump and oil pan.
1984 models with two-piece neoprene seals
Refer to illustrations 20. 17, 20.20 and 20.21
13 Always service both halves of the rear main oil seal. While replacement of this seal is much easier with the engine removed from the ve-
f-i; 2 -J
....
! j
1
,004 SHIM STOCK
___
/ _
__,
-~-
t
11/64
20.21
A protective tool used for installing the upper seal
half of a two-piece neoprene seal
hicle, the job can be done with the engine in place.
1 4 Remove the oil pan and oil pump as described previously in Sections 17 and 18.
15 Remove the rear main bearing cap from the engine.
16 Using a screwdriver, pry the lower half of the oil seal from the bearing cap.
1 7 To remove the upper half of the seal, use a small hammer and a
brass pin punch to roll the seal around the crankshaft journal. Tap one
end of the seal with the hammer and punch (be careful not to strike
the crankshaft) until the other end of the seal protrudes enough to pull
the seal out with pliers (see illustration).
18 Remove all sealant and foreign material from the main bearing cap.
Do not use an abrasive cleaner for this.
19 Inspect the components for nicks, scratches and burrs at all sealing
surfaces. Remove any defects with a fine file or deburring tool.
2 0 Apply a very thin coat of RTV gasket sealant to the outer surface
of the upper seal as shown (see illustration). Do not get any sealant
on the seal lips.
21 Included in the purchase of the rear main oil seal should be a small
The Motor Manual Guy
Chapter 2 Part B
V6 engine
2B-13
ALIGNMENT HOLE
DUST LIP
ATTACHING SCREWS
20.31 Using a screwdriver, pry the rear main seal from
the bore
be careful not t o scratch the crankshaft seal
surface or the edge of the seal bore
"
COLLAR
20.32 Using the rear main oil seal installation
tool
1985 and later models
the rear main oil seal end and oil pan rear seal groove. Be sure to keep
the sealant off the rear main oil seal and bearing and out of the drain sJot.
25 Just before installing the cap, apply a light coat of moly-base grease
or engine assembly lube to the crankshaft surface that will contact
the seal.
2 6 Install the rear main bearing cap and tighten the bolts to the
specified torque.
27 Install the oil pump and oil pan.
1985 and later models with one-piece seals
21 .1
V6 engine mounts - exploded view
plastic installation tool; if not, a tool may be fashioned from an old
feeler gauge blade (see illustration).
22 With the upper half of the seal positioned so that the seal lip faces
toward the front of the engine and the small dust lip faces toward the
flywheel, install the seal by rolling it around the crankshaft using the
installation tool as a "shoehorn" for protection.
23 Apply sealant as described in Step 2 0 to the other half of the seal
and install it in the bearing cap.
2 4 Apply a 1132-inch bead of anaerobic sealant to the cap between
Refer to illustrations 20.3 1 and 20.32
Note: Special tools, as noted in the Steps which follow, are required
for this procedure. They are available from your dealer or may, in some
cases, be rented from an auto parts store or tool rental shop.
28 Beginning in 1985, a 360-degree lip-type seal is utilized, which
allows the oil pan to remain in place when performing this procedure.
29 Remove the transmission (refer to Chapter 7).
3 0 Remove the flywheel or driveplate (see Section 19).
31 Pry out the old seal, taking care not to mar the crankshaft surface
(see illustration). Inspect the crankshaft for scratches, burrs and nicks
on the sealing surfaces.
32 A special seal installation tool (no. J-34686) is required to properly
seat the seal in the bore without damaging it (see illustration). Lubricate
the seal bore, seal lip and sealing surface on the crankshaft with engine
oil. Slide the seal over the mandril on the tool until the dust lip on the
seal bottoms squarely against the collar of the tool.
3 3 Position the dowel pin on the tool in the dowel pin hole in the crankshaft and secure the tool to the crankshaft.
3 4 Turn the T-handle of the tool until the collar pushes the seal into
the bore completely. Make sure the seal is installed squarely.
3 5 To complete the operation install the flywheel (or driveplate) and
transmission, then start the engine and check for leaks.
21 Engine mounts - check and replacement
Refer t o illustration 2 1.1
Refer t o Chapter 2, Part A, Section 22 for this procedure, but note
that the V6 mounts are slightly different (see illustration) in ways that
don't affect the check and replacement procedures.
28
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
Contents
See Chapter 1
Air filter and PCV filter replacement
Camshaft. bearings and lifters
removal. inspection
and installation
14
Compression check
See Chapter 2 D
9
Cylinder head
removal and installation
See Chapter 1
Drivebelt check, adjustment and replacement . . .
Engine
removal and installation
See Chapter 2 D
Engine mounts
check and replacement
19
Engine oil and filter change
See Chapter 1
Engine oil level check
See Chapter 1
See Chapter 2 D
Engine overhaul
general information
8
Exhaust manifold
removal and installation
Flywheelldriveplate
removal and installation
17
Front crankshaft oil seal
replacement
11
General information
1
7
Intake manifold
removal and installation
Oil pan.removal and installation
15
Oil pump
removal and installation
16
Rear crankshaft oil seal
replacement
18
2
Repair operations possible w i t h the engine in the vehicle
4
Rocker arm cover
removal and installation
Rocker arms and pushrods - removal, inspection
and installation
5
Timing chain and sprockets
inspection, removal
and installation
13
12
removal and installation
Timing chain cover
3
Top Dead Center (TDC) for number one piston
locating . . .
replacement
6
Valve spring, retainer and seals
Vibration damper
removal and installation
10
Water pump
removal and installation
See Chapter 3
Specifications
General
r
2 4 3 c u. in (4.0 liters)
1-2-3-4-5-6
1-5-3-6-2-4
Displacement
Cylinder numbers (front-to-rear)
Firing order
Camshaft
Lobe lift (intake and exhaust)
End play
Journal diameter
No. 1
No. 2
No. 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No. 4
Journal-to-bearing (oil) clearance
®®©@@CD
0.253 in
None
ENGINE FRONT
2.029
2.01 9
2.009
1.999
0.001
to
to
to
to
to
2.030
2.020
2.010
2.000
0.003
in
in
in
in
in
Torque specifications
Ft-lbs (unless otherwise indicated)
Camshaft sprocket bolt
Crankshaft pulley-to-vibration damper bolts
Cylinder head bolts
Step A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step C
Bolt no . 11
All other bolts
Flywheelldriveplate bolts
Intake and exhaust manifold retaining bolts and nuts
No. 1 exhaust manifold nut
All other bolts/nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pan mounting bolts
1/4 X 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5/16 X 1 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
50
20
.
.
22
45
100
11 0
105
.
.
.
30
23
7
11
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
Oil pump mounting bolt
Short
Long
Rear main bearing cap bolts
Rocker arm bolts
Rocker arm cover-to-cylinder head bolts
With RTV
With permanent gasket
Tensioner bracket-to-block bolts
Timing chain cover-to-block
Bolts
Studs
Vibration damper center bolt (lubricated)
1
2C-1
10
17
80
19
28 in-lbs
55 in-lbs
14
5
16
80
General information
This Part of Chapter 2 is devoted to in-vehicle repair procedures for
the inline six-cylinder engine. All information concerning engine removal
and installation and engine block and cylinder head overhaul can be
found in Part D of this Chapter.
The following repair procedures are based on the assumption that
the engine is installed in the vehicle. If the engine has been removed
from the vehicle and mounted on a stand, many of the steps outlined
in this Part of Chapter 2 will not apply.
The Specifications included in this Part of Chapter 2 apply only t o
the procedures contained in this Part. Part D of Chapter 2 contains the
Specifications necessary for cylinder head and engine block rebuilding.
in the vehicle. Replacement of the camshaft and timing chain and
sprockets is also possible with the engine in the vehicle.
In extreme cases caused by a lack of necessary equipment, repair
or replacement of piston rings, pistons, connecting rods and rod bearings is possible with the engine in the vehicle. However, this practice
is not recommended because of the cleaning and preparation work that
must be done to the components involved.
3
Top Dead Center (TDC) for number one piston
locating
Refer to illustrations 3. la, 3. 1b and 3. 1c
See Chapter 2, Part A, Section 3 for this procedure, but refer to the
illustrations and specifications included in this Section.
2 Repair operations possible with the engine in the vehicle
Many major repair operations can be accomplished without removing
the engine from the vehicle.
Clean the engine compartment and the exterior of the engine with
some type of pressure washer before any work is done. It will make
the job easier and help keep dirt out of the internal areas of the engine.
Remove the hood, if necessary, to improve access to the engine as
repairs are performed (refer t o Chapter 11 if necessary).
If vacuum, exhaust, oil or coolant leaks develop, indicating a need
for gasket or seal replacement, the repairs can generally be made with
the engine in the vehicle. The intake and exhaust manifold gaskets,
timing cover gasket, oil pan gasket, crankshaft oil seals and cylinder
head gaskets are all accessible with the engine in place.
Exterior engine components, such as the intake and exhaust
manifolds, the oil pan (and the oil pump), the water pump, the starter
motor, the alternator, the distributor and the fuel system components
can be removed for repair with the engine in place.
Since the cylinder heads can be removed without pulling the engine,
valve component servicing can also be accomplished with the engine
b Locate the number one spark plug terminal on the
distributor cap, make a mark on the distributor housing,
directly under the number one plug terminal, . . .
Align the notch (arrow) on the vibration damper with
on the timing chain cover
the
3.1c
...
then remove the distributor cap and verify that the
rotor is pointing at the mark (arrow)
2C
The Motor Manual Guy
2C-2
Chapter 2 Part C
lnline six-cylinder engine
4.3
4
4.1
View from above shows locations of crankcase breather
tube and hose (arrows)
Use a soft-face mallet t o break the cover loose - DO
NOT pry between the cover and head
- removal and installation
Refer to illustrations 4.1, 4.3 and 4.4
1 Pull the crankcase breather tube and hose off the rocker arm cover
(see illustration).
2 Remove the cruise control servo, if equipped.
3 Remove the wire loom clips (see illustration), noting the locations
of their studs for reinstallation.
4 Remove the rocker arm cover retaining bolts and lift the cover off.
If the cover is stuck, tap on it gently with a soft-face mallet (see illustration). Do not pry on the gasket flange. Note: These covers have
a reusable pre-cured RTV gasket that is attached to the cover.
5 Clean the sealing surfaces, removing any traces of oil with lacquer
thinner or acetone and a clean rag.
6 Small cracks in the pre-cured gasket are allowable and can be
repaired by applying RTV sealer to the cracked area before the cover
is installed.
7 Install the cover and bolts. Tighten the bolts to the specified torque.
8 Reinstall the crankcase breather hoses and cruise control servo,
if equipped.
9 Run the engine and check for oil leaks.
5
4.4
Rocker arm cover
Pull off the wire loom clips
Rocker arms and
and installation
pushrods _ _ _ _ _ _ _ __
- removal, inspection
---Refer to illustrations 5.2, 5.3 and 5.4
Removal
1 Remove the rocker arm cover (see Section 4).
2 Beginning at the front of the cylinder head, loosen and remove the
rocker arm mounting bolts in pairs (see illustration).
A
d
5.3 Rocker arm components - exploded view
5.2 Go back and forth between the intake and exhaust
rocker arms, loosening each bolt 114-turn at a time
A Bolt
B Bridge
C Fulcrum
D Rocker arm
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
2C-3
Installation
8 Lubricate the lower end of each pushrod with clean engine oil or
moly-base grease and install it in its original location. Make sure each
pushrod seats completely in the lifter socket.
9 Bring the number one piston to top dead center on the compression
stroke (Section 3).
1 0 Apply moly-base grease t o the ends of the valve stems and the
upper ends of the pushrods before placing the rocker arms in position.
1 1 Apply moly-base grease t o the fulcrums to prevent damage to the
mating surfaces before engine oil pressure builds up. Install the rocker
arms, fulcrums, bridges and bolts in their original locations. Tighten
the bolts to the specified torque.
1 2 Install the rocker arm cover (see Section 4).
13 Start the engine, listen for unusual valvetrain noises and check
for oil leaks at the rocker arm cover joint.
6
Valve spring, retainer and seals - replacement
See Chapter 2, Part A, Section 6 for this procedure, but be sure to
follow the rocker arm cover and rocker arm/push rod procedures outlined
in this Part.
5.4
Store the pushrods in a box like this to ensure
reinstallation in the same location
3 Remove the rocker arms, bridges and fulcrums (see illustration)
and store them with their respective mounting bolts. Store each set
of rocker arm components separately in a marked plastic bag to ensure they are reinstalled in their original locations. The bridges may
be reinstalled in any location.
4 Remove the pushrods and store them separately to make sure they
don't get mixed up during installation (see illustration).
Inspection
5 Check each rocker arm for wear, cracks and other damage, especially where the pushrods and valve stems contact the rocker arm faces.
Check the fulcrum seat in each rocker arm and the fulcrum faces. Look
for galling, stress cracks and unusual wear patterns. If the rocker arms
are worn or damaged, replace them with new ones and install new
fulcrums as well.
6 Make sure the oil hole at the pushrod end of each rocker arm is
open.
7 Inspect the push rods for cracks and excessive wear at the ends.
Roll each pushrod across a piece of plate glass t o see if it's bent (if
it wobbles, it's bent).
7.5
Lift the vacuum connector from its bracket and pull it apart
7
Intake manifold - removal and installation
Refer to illustrations 7.5, 7.6, 7. 1 1, 7. 12 and 7.20
Note: Since the intake and exhaust manifolds share a common gasket,
they must be removed and replaced at the same time.
1 Disconnect the negative cable from the battery.
2 Remove the air cleaner assembly and the throttle cable (see Chapter 4).
3 On automatic transmission equipped models, disconnect the transmission line pressure (TV) cable (see Chapter 7, Part B).
4 Detach the cruise control cable, if equipped.
5 Disconnect the vacuum connector on the intake manifold by lifting
the connector assembly up and out of the bracket and then pulling it
apart (see illustration).
6 Label and then disconnect all vacuum and electrical connectors
on the intake manifold (see illustration).
7 Relieve the fuel pressure and then disconnect the fuel supply and
return lines from the fuel rail assembly (see Chapter 4). Cap the open
ends.
8 Loosen the serpentine drivebelt (see Chapter 1 ).
9 Remove the power steering pump and bracket from the intake manifold and set it aside without disconnecting the hoses. Be sure t o leave
the pump in an upright position so fluid won't spill.
1 0 Remove the fuel rail and injectors (see Chapter 4).
7.6
Label the connections before detaching them
2C
The Motor Manual Guy
2C-4
Chapter 2 Part C
lnline six-cylinder engine
7.1 1 Remove the bolts (arrows) and lift the heat shield off
7.12 Four of the intake manifold mounting bolts (arrows) can be
accessed from the top - you must reach below the manifold to
remove the remaining four, which are visible in illustration 7.20
11 Remove the intake manifold heat shield (see illustration).
12 Unbolt the intake manifold, referring to the accompanying illustration and illustration 7.20.
1 3 Remove the EGR tube from the intake manifold (see Chapter 6).
Pull the manifold away from the engine slightly to disengage it from
the locating dowels in the cylinder head, then lift the manifold out of
the engine compartment.
1 4 Remove the exhaust manifold (see Section 8). This is necessary
because the intake and exhaust manifolds share a common gasket.
1 5 Thoroughly clean the gasket mating surfaces, removing all traces
of old gasket material.
1 6 If the manifold is being replaced, make sure all the fittings, etc.
are transferred t o the replacement manifold.
17 Position a new gasket on the cylinder head, using the locating
dowels to hold it in place. Install the exhaust manifold and hand tighten
the nuts.
18 Position the intake manifold loosely on the cylinder head.
19 Install the EGR tube between the manifolds.
2 0 Install the manifold retaining bolts and tighten all fasteners in sequence (see illustration) to the specified torque. Note that nut number
one (1) requires a greater torque than the others.
21 Reinstall the remaining parts in the reverse order of removal.
Caution: Before connecting the fuel lines to the fuel rail, replace the
O-rings in the quick-connect fuel line couplings (see Chapter 4).
22 Run the engine and checl for fuel, vacuum and exhaust leaks.
8 Exhaust manifold
- removal and installation
Warning: Allow the engine to cool completely before following this
procedure.
1 Remove the intake manifold (see Section 7).
2 Apply penetrating oil to the threads of the exhaust manifold attaching studs and the exhaust pipe-to-manifold attaching bolts.
3 Remove the t w o bolts and nuts that secure the exhaust manifold
to the exhaust pipe and detach the pipe from the manifold.
4 Remove the three nuts that secure the exhaust manifold t o the
cylinder head and pull the manifold off the engine.
5 Remove all traces of old gasket material from the mating surfaces.
6 If the manifold gasket was blown out, have the manifold checked
for warpage by an automotive machine shop and repaired as necessary.
7.20 Intake/exhaust manifold bolt/nut tightening sequence
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
7 Position a new gasket on the locating dowels and slide the manifold
over the studs.
8 Install the attaching nuts on the studs finger tight.
9 Reinstall the intake manifold (see Section 7) and tighten all fasteners, in the sequence shown in illustration 7.20, t o the specified torque.
1 0 Reconnect the exhaust pipe, run the engine and check for exhaust
leaks.
2C-5
1 0 Loosen the alternator drivebelt and remove the alternator bracketto-cylinder head mounting bolt.
1 1 Unplug the wiring and unbolt the air conditioning compressor (see
Chapter 3) without disconnecting the refrigerant hoses. Set the compressor aside and remove the upper t w o bolts from the bracket (see
illustration).
All models
9
Cylinder head - removal and installation
Refer to illustrations 9. 11, 9.15, 9.19 and 9.21
Caution: Allow the engine to cool completely before following this
procedure.
1 Disconnect the negative cable from the battery.
2 Drain the coolant from the radiator and the engine block (see Chapter 1).
3 Remove the air cleaner assembly (see Chapter 4).
4 Detach the fuel pipe and vacuum advance hose.
5 Remove the rocker arm cover (see Section 4).
6 Remove the rocker arms and pushrods (see Section 5).
7 Unbolt the power steering pump bracket (if equipped) and set the
pump aside without disconnecting the hoses. Leave the pump upright
so fluid doesn't spill.
8 Remove the intake and exhaust manifolds (see Sections 7 and 8).
Air conditioned models
9 Remove the bracket on the cylinder head that supports the idler
pulley for the air conditioning compressor drivebelt (see Chapter 1 ).
9.1 1 Set the compressor aside with the refrigerant lines still
attached
then remove the upper bracket bolts (arrows)
1 2 Label the spark plug wires and remove the distributor cap with the
wires attached to it. Remove the spark plugs as described in Chapter 1.
1 3 Disconnect the wire from the temperature sending unit, which is
on the top left rear corner of the cylinder head. Also disconnect the
battery ground cable, which is on the right side of the engine.
1 4 Remove the ignition coil and bracket assembly (see Chapter 5).
15 Remove the heater hose bracket (see illustration).
16 Remove the 1 4 cylinder head bolts and lift the head off the engine.
If the head sticks to the engine, insert a prybar into an exhaust port
and pry gently to break the seal.
1 7 Thoroughly clean the gasket mating surfaces, removing all traces
of old gasket material. Stuff shop towels into each cylinder so scraped
material doesn't fall in.
18 Inspect the head for cracks and warpage. See Chapter 2, Part D,
for cylinder head servicing information. If you are replacing the cylinder
head, be sure to transfer all fittings, etc. to the new head.
1 9 Apply an even coat of Perfect Seal sealing compound (or equivalent) to both sides of the replacement head gasket. Position the new
head gasket on the engine block with the word TOP facing up (see
illustration).
2 0 Install the cylinder head on the engine block.
21 Coat the threads of bolt number 1 1 (see illustration) with Loctite
9.15
Remove the two bolts (arrows) to disconnect the
heater hose bracket
...
--- ---- -9.19
lnstall the head gasket with the TOP mark facing up
9 . 2 1 Cylinder head bolt tightening sequence - be sure to
coat the threads of bolt no. 11 (arrow) with Locktite 5 9 2
sealant (or 'equivalent)
The Motor Manual Guy
Chapter 2 Part C
2C-6
--
lnline six-cylinder engine
592 sealant (or equivalent) and install the head bolts hand tight. Note:
Clean each bolt and mark it with a dab of paint. Replace any bolts which
were painted and reused during an earlier servicing operation.
22 Tighten the cylinder head bolts in sequence (see illustration 9.21),
according to the following procedure:
Step A
tighten all bolts (1 through 14) in sequence to the specified
torque for Step A.
Step B - tighten all bolts in sequence to the specified torque for
Step B.
Step C -tighten all bolts except no. 11 to the specified torque for
Step C.
Caution: In Step C, bolt no. I I is tightened to a lower torque than the
rest of the bolts. Do not overtighten it. Tighten bolt no. I I to the
specified torque for Step C.
23 Reinstall the remaining components in the reverse order of removal.
2 4 Add coolant and run the engine, checking for proper operation and
coolant and oil leaks.
--
10
Vibration damper - removal and installation
Refer to illustrations 10.6 and 10.7
I Disconnect the negative cable from the battery.
2 Raise the front of the vehicle and support it securely on jackstands.
3 -Remove the belly pan which is mounted below the front of the
engine.
4 Remove the drivebelts (see Chapter 1 ).
5 Remove the radiator and cooling tan(s) as described in Chapter 3.
6 Remove the vibration damper retaining bolt and washer. Note: To
prevent the crankshaft from rotating, place two 5/16 x I - 1/2-inch long
bolts into the damper holes and hold a pry bar between them (see
illustration). Rotate the crankshaft until the bar contacts the frame.
7 Using a vibration damper removal tool (see illustration), pull the
damper off the crankshaft.
8 Clean and inspect the area on the center hub of the damper where
the front crankshaft oil seal contacts it. Minor imperfections can be
cleaned up with emery cloth. If there is a groove worn in the hub.
replace the vibration damper or have a special sleeve installed on the
hub to restore the contact surface.
9 Apply clean engine oil to the seal contact surface of the damper hub.
1 0 Align the key slot of the vibration damper hub with the crankshaft
key and tap the damper onto the crankshaft with a soft-face mallet.
11 lnstall the vibration damper bolt and tighten it t o the specified
torque.
12 Reinstall the remaining parts in the reverse order of removal.
10.7 Use a vibration damper removal tool such as this
one - do not use a gear puller with jaws; i t will damage
the damper
11
Front crankshaft oil seal - replacement
Refer to illustrations 1.2 and 1.3
1 Remove the vibration damper (Section 10).
2 Carefully pry the oil seal out of the timing chain cover with a seal
removal tool or screwdriver (see illustration). Don't scratch the cover
bore or damage the crankshaft in the process (if the crankshaft is
damaged the new seal will end up leaking).
3 Clean the bore in the cover and coat the outer edge of the new
seal with engine oil or multi-purpose grease. Using a socket with an
outside diameter slightly smaller than the outside diameter of the seal,
carefully drive the new seal into place with a hammer (see illustration).
If a socket isn't available, a short section of large diameter pipe will
work. Check the seal after installation to be sure that the spring didn't
pop out of place.
4 Reinstall the vibration damper.
5 The parts removed to gain access to the damper can now be reinstalled.
6 Run the engine and check for leaks.
10.6
11.2
Install t w o bolts in the damper and use them t o keep
the crankshaft from rotating
Pry the old seal out with a seal removal tool (shown
here) or a screwdriver
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
1 1 . 3 Gently drive the new seal into place with a hammer
and large socket
12
Timing chain cover
removal and installation
Refer to illustrations 12.4, 12.7 and 12.13
1 Disconnect the negative cable from the battery.
2 Remove the fan, fan shroud, radiator and water pump pulley (see
Chapter 3).
3 Remove the vibration damper (see Section 10).
4 Unbolt the alternator and bracket assembly (see illustration).
5 Remove the oil pan-to-timing chain cover bolts and timing chain
cover-to-engine block bolts.
6 Separate the timing chain cover from the engine. If necessary, tap
on it gently with a soft-face mallet to break the seal. Temporarily stuff
a rag into the oil pan opening to prevent entry of debris.
7 Cut off the oil pan side gasket end tabs flush with the front face
of the engine block (see illustration). Save the cut off gasket tabs for
reference later.
8 Clean the mating surfaces of the timing chain cover, oil pan and
engine block, removing all traces of oil and old gasket material.
9 Apply RTV sealer to both sides of the new timing chain cover-to-
12.7
Cut off the end tabs at both sides where the oil pan
and engine block meet
2C-7
1 2 . 4 Once the alternator has been removed, remove the
bracket retaining nuts (arrows), then unbolt the timing
chain cover
engine block gasket and position the gasket on the engine.
1 0 Using the end tabs you cut off as guides, trim the replacement
oil pan side gasket ends to the appropriate sizes. Apply cement to the
gasket ends and install them on the exposed portions of the oil pan
side rails.
1 1 Using RTV sealant, generously coat the timing chain cover end
tab recesses of the new timing chain cover-to-oil pan seal. Position
the seal on the timing chain cover. Apply engine oil to the seal-to-oil
pan contact surface.
12 Position the timing chain cover on the engine block.
1 3 Use the vibration damper t o center the timing chain cover (see illustration). Be sure the old oil seal (not the new one) is in place, as
it may be damaged.
1 4 Install the timing chain cover-to-block and oil pan-to-cover bolts
and tighten them to the specified torque.
15 Replace the front crankshaft oil seal (see Section 11 ).
16 With the key inserted in the crankshaft, install the vibration damper
as described in Section 10.
17 Reinstall the remaining components in the reverse order of removal.
1 8 Run the engine and check for oil leaks.
12.13
Use the vibration damper to center the timing chain
cover during installation
2C
The Motor Manual Guy
Chapter 2 Part C
2C-8
13.3 Slip the oil slinger off the
crankshaft, noting that the cupped side
faces away from the engine
lnline six-cylinder engine
13.7 With the number one piston at
Top Dead Center, the timing chain
sprocket index dots (arrows) are
directly opposite each other
Removal
1 3 Timing chain and sprockets - inspection, removal
and installation
7
Refer to illustrations 13.3, 13.7, 13.8, 13.9, 13. Oa, 13. 10b
and 13.13
1 Set the number one piston at Top Dead Center (see Section 3).
2 Remove the timing chain cover (see Section 12).
Inspection
3 Slip the oil slinger off the crankshaft (see illustration) and reinstall
the vibration damper bolt. Using this bolt, rotate the crankshaft clockwise just enough t o take up the slack on one side of the chain.
4 Count the pins on the timing chain. The correct timing chain has 48
pins. A chain with more pins will cause excessive slack.
5 Establish a reference point on the block. Move the slack side of
the chain from side-to-side with your fingers and measure the movement. The difference between the t w o measurements is the deflection.
6 If the deflection exceeds 112-inch, replace the timing chain and
sprockets.
CAMSHAFT
SPROCKET
\
13.8 Remove the thrust pin and spring
(arrow), then remove the bolt in the
center of the camshaft sprocket - put
a large screwdriver through one of
the holes in the sprocket t o keep
it from turning
Align the sprocket timing marks (see illustration).
8 Remove the camshaft thrust pin and spring and the sprocket retaining bolt and washer (see illustration).
9 Pull the crankshaft sprocket, camshaft sprocket and timing chain
off as an assembly (see illustration). Caution: Do not turn the crankshaft
or camshaft while the timing chain is removed.
Installation
1 0 Be sure the crankshaft key is still pointing up. Note the locations
of the locating dowel on the camshaft and the corresponding hole in
the cam sprocket (see illustrations).
1 1 Pre-assemble the timing chain, crankshaft sprocket and camshaft
sprocket with the timing marks aligned and facing out. Slip the assembly onto the engine in such a way that a line drawn through the
timing marks will also pass through the centers of the sprockets.
12 Install the camshaft sprocket bolt and tighten it t o the specified
torque. Reinstall the thrust pin and spring.
13 To verify the correct installation of the timing chain, turn the crankshaft clockwise until the camshaft sprocket timing mark is at the one
CRANKSHAFT
KET
CHAIN
13.9
Remove and install the chain and sprockets
as an assembly
13.10a
Note that the engine side of the camshaft
sprocket has a hole (arrow) . . .
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
2C-9
CAMSHAFT
SPROCKET
CRANKSHAFT
SPROCKET
...
for the camshaft locating dowel (arrow)
13.1 Ob
sure they are aligned properly during installation
- be
o'clock position. This positions the crankshaft sprocket timing mark
where the adjacent tooth meshes with the chain at the three o'clock
position. There must be 15 chain pins between the sprocket timing
marks (see illustration).
14 Install the crankshaft oil slinger on the crankshaft with the cupped
side facing out.
15 Install the timing chain cover and vibration damper as described
in Sections 10 and 12.
16 Reinstall the remaining parts in the reverse order of removal.
17 Run the engine and check for oil leaks and proper operation.
14 Camshaft, bearings and lifters
and installation
- removal,
inspection
Refer to illustrations 14.9 and 14. 1 1
1 The extent of camshaft wear can be determined by measuring the
lobe lift. This procedure does not involve removing the camshaft. Refer
t o Chapter 2, Part A, Section 16 for the lobe lift measuring procedure,
13.13 To verify correct installation. turn the crankshaft
clockwise until the timing marks are positioned as shown
and count the pins between the marks
but use the specifications provided in this Part of Chaoter 2.
2 To remove the lifters only, follow steps 7 through 9, 12, 16 and
17 of this procedure.
3 Remove the radiator, fan and fan shroud (see Chapter 3).
4 On air conditioned models, unbolt the condenser assembly as a
charged unit (see Chapter 3) without disconnecting the refrigerant lines.
Set the condenser aside. It may be necessary to remove the battery
case (see Chapter 5).
5 Remove the distributor (see Chapter 5).
6 Remove the front bumper and/or grille as necessary for the camshaft t o be slid out the front of the engine (see Chapter 1 1 ).
7 Label and then remove the spark plug wires from the spark plugs.
8 Remove the cylinder head (see Section 9).
9 Remove the valve lifters (see illustration) and store them separately
so they can be reinstalled in the same bores.
10 Remove the timing chain and sprockets (see Section 13).
1 1 Carefully pull the camshaft out. Temporarily install the sprocket
bolt, if necessary, to use as a handle. Support the cam so the lobes
don't nick or gouge the bearings as it's withdrawn (see illustration).
12 See Chapter 2, Part A, Section 1 1 for the lifter inspection pro-
14.9 Remove the lifters with a magnetic pick-up tool
14.11 Support the camshaft as you slowly withdraw it
(shown here) or a special lifter removal tool
from the block
The Motor Manual Guy
Chapter 2 Part C
2C-10
lnline six-cylinder engine
cedure. Camshaft and bearing inspection are covered in Chapter 2,
Part A, Section 16. Be sure to use the specifications provided in this
Part of Chapter 2.
13 Camshaft bearing replacement requires special tools and expertise
that place it outside the scope of the home mechanic. Remove the
engine and take the block to an automotive machine shop to ensure
the job is done correctly. Note: If the camshaft appears to have been
rubbing hard against the timing chain cover, first check the camshaft
thrust pin and spring and then examine the oil pressure relief holes in
the rear cam journal to make sure they are open.
1 4 Lubricate the camshaft journals and lobes with moly-base grease
or engine assembly lube.
15 Slide the camshaft into the engine. Support the cam near the block
and be careful not to scrape or nick the bearings.
16 The rest of the installation procedure is the reverse of removal.
17 Before starting and running the engine, change the oil and filter
(see Chapter 1 ).
15
Oil pan
-
removal and installation
Refer to illustrations 15.10, 15.12, 15.13 and 15.16
1 Disconnect the negative cable from the battery.
2 Raise the vehicle and support it securely on jackstands.
3 Remove the belly pan from under the front of the engine.
4 Drain the oil and replace the oil filter (see Chapter 1 ).
5 Remove the starter motor (see Chapter 5).
6 Remove the bellhousing inspection cover from the front of the
transmission.
7 Detach the steering damper from the center steering link (see
Chapter 10, Section 16).
8 Support the front axle with a jack and remove the lower shock
absorber bolts.
9 Lower the jack and allow the axle to hang free.
1 0 Mark the locations of the oil pan mounting studs (see illustration).
11 Remove the oil pan mounting bolts/studs and carefully separate
the pan from the engine block, If the pan sticks to the block, tap the
side of the pan gently with a soft-face mallet.
12 Set the oil pan on the axle and remove the oil pump and pickup
tube (see illustration).
1 3 Remove the oil pan by sliding it out to t o the rear (see illustration).
1 4 Thoroughly clean the mating surfaces, removing all traces of oil
and old gasket material.
15 Check the oil pan flange for distortion and warpage. Straighten
the flange by placing the distorted area on a block of wood and pounding it flat with a hammer.
16 Position new gaskets (see illustration) on the pan with Jeep Spraya-Gasket (or equivalent). Apply a generous amount of RTV sealant at
15.10
Mark the locations of the studs with paint to
ensure proper reassembly
15.12 The oil pickup tube interferes with pan
removal - remove the two attaching bolts and detach
the oil pump (arrow), . . .
OIL PAN-TO-BEARING
CAP SEAL
15.13 . . . then remove the oil pan from the rear by
sliding it out between the axle and bellhousing
15.1 6
OIL PAN
GASKET SET
OIL PAN
TIMING
CASE COVER
Oil pan gaskets - exploded view
The Motor Manual Guy
Chapter 2 Part C
lnline six-cylinder engine
2C-1 1
the corners where the gaskets join. Coat the inside curved surface of
the replacement rear gasket section (where it contacts the bearing cap)
with soap.
17 Slide the oil pan up under the engine and reinstall the oil pump
and pickup tube, tighening the oil pump mounting bolts to the specified
torque. Install the oil pan and tighten the bolts to the specified torque,
working from the center out in several steps.
18 Reinstall the remaining parts in the reverse order of removal.
19 Check that the drain plug is tight and then add the amount of oil
specified in Chapter 1.
2 0 Run the engine and check for oil leaks.
16
Oil pump - removal and installation
See Chapter 2, Part A, Section 19 for this procedure, but be sure
to use the torque specifications and illustration 15.1 2 in this Part of
Chapter 2.
17
18.3a
Drive one side of the upper seal i n
...
Flywheel/driveplate - removal and installation
Refer t o Chapter 2, Part A, Section 2 0 for this procedure, but be
sure to use the torque specifications in this Part of Chapter 2.
1 8 Rear crankshaft oil seal
- replacement
Refer to illustrations 18.3a, 18.3b and 18.5
1 Remove the oil pan (see Section 15).
2 Remove the rear main bearing cap and pry the old seal half out
of the bearing cap with a small screwdriver.
3 Carefully drive the old upper main seal out with a small brass punch
and a hammer until it protrudes sufficiently from the engine block to
be gripped with needle-nose pliers and removed (see illustrations). Use
great care t o avoid damaging the crankshaft.
4 Thoroughly clean the main bearing cap and the rear of the block/
crankshaft, removing all traces of oil and old sealer.
5 Coat the lip of the new upper seal with engine oil; coat the outside
surface with liquid soap (see illustration).
6 Insert the seal into the groove in the engine block with the lip facing
forward.
7 Coat both sides of the lower seal ends with RTV sealer and put
liquid soap on the outside of the seal (see illustration 18.5). Do not
apply RTV or soap to the seal lip. Press the seal into place in the cap
and apply a film of engine oil to the seal lip. Caution: Do not apply
sealant to the cylinder block mating surfaces of the rear main bearing
cap. Doing this would alter the bearing-to-journal clearance.
8 Apply RTV sealer to the chamfered edges of the rear main bearing
cap (see illustration 18.5) and install the cap. Tighten the bolts to the
specified torque.
9 Reinstall the remaining components in the reverse order of removal.
1 0 Add the amount of oil specified in Chapter 1, run the engine and
check for oil leaks.
1 9 Engine mounts - check and replacement
Refer to Chapter 2, Part A, Section 22. The inline six-cylinder engine
mounts are slightly different, but this doesn't affect the check and
replacement procedures.
2C
18.3b . . . until the other side protrudes far enough to
grasp it with needle-nose pliers and pull it out
ENGINE OIL ON LIP
LIQUID SOAP
ON OUTSIDE
I
RTV SEALER ON
TOP AND
OF BOTH
OF SEAL
- RTV SEALER ON
. CHAMFERED
EDGES
RTV SEALER ON
CHAMFERED EDGES
18.5
Rear main seal components
exploded view
The Motor Manual Guy
Chapter 2 Part D
General engine overhaul procedures
Contents
Crankshaft - inspection.
Crankshaft - installation and main bearing oil
clearancecheck . . . . . . . . . . . . . . . . . . . . .
Crankshaft - removal
Cylinder compression check
Cylinder head - cleaning and inspection.
Cylinder head - disassembly
Cylinder head
reassembly.
Cylinder honing
Engine block - cleaning..
Engine block - inspection
Engine overhaul - disassembly sequence
Engine overhaul - general information
Engine overhaul - reassembly sequence.
18
. . . . . . . . . . . 22
13
3
9
8
11
16
14
15
7
2
20
Engine rebuilding alternatives . . . . . . . . . . . . . . . . . . . . . . . .
Engine - removal and installation. . . . . . . . . . . . . . . . . . . . .
Engine removal - methods and precautions
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initial start-up and break-in after overhaul
Main and connecting rod bearings - inspection
Pistons/connecting rods - inspection
Pistonslconnecting rods - installation and rod bearing
oil clearance check
removal
Piston/connecting rods
Piston rings
installation . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear main oil seal installation
Valves - servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications
Four-cylinder engine
General
Cylinder compression pressure
Maximum allowable variation between cylinders
Oil pressure
At idle (800 rpm)
Above 1600 rpm
155 to 185 psi
30 psi
25 t o 35 psi
37 to 75 psi
Engine block
Cylinder bore diameter (standard)
Maximum allowable taper and out-of-round
Warpage limit.
Valve lifter bore diameter
3.8751 to 3.8775 in
0.001 in
0.002 in per 6 inches
0.9055 to 0.9065 in
Cylinder head and valves
Cylinder head warpage limit
Minimum valve margin
Valve stem diameter.
Valve stem-to-guide clearance
Valve spring pressure
Valve closed
Valve open
Valve spring free length
Valve spring installed height
Valve lifter
Diameter.
Lifter-to-bore clearance
0.002 in per 6 in (0.006in overall)
1132-in
0.311 to 0.312 in
0.001 to 0.003 in
80 t o 90 Ibs at 1.64 in
200 Ibs at 1.216 in
1.967 in
Not available
0.904 to 0.9045 in
0.001 to 0.0025 in
6
5
4
1
25
19
17
24
12
21
23
10
The Motor Manual Guy
Chapter 2 Part D
General engine overhaul procedures
Crankshaft and connecting rods
Connecting rod journal
Diameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bearing oil clearance
Desired
Allowable
Connecting rod side clearance (end play).
Main bearing journal
Diameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bearing oil clearance
Desired
Allowable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft end play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum taper and out-of-round (all journals) . . . . . . . . . . . .
2.0934 to 2.0955 in
0.001 5 to 0.0020 in
0.001 to 0.0025 in
0.0010 to 0.0019 in
2.4996 to 2.5001 in
0.002 in
0.001 to 0.0025 in
0.0015 to 0.0065 in
0.0005 in
Pistons and rings
Piston-to-bore clearance
Piston ring end gap
Compression rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring (steel rail) . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring side clearance
Compression rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque specifications
*
0.0013 to 0.0021 in
0.0010 to 0.020 in
0.015 to 0.055 in
0.001 to 0.0032 in
0.001 to 0.0095 in
Ft-lbs
Connecting rod cap nuts. . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing cap bolts
* Note: Refer to Part A for additional torque specifications.
..
33
80
V 6 engine
General
Cylinder compression pressure . . . . . . . . . . . . . . . . . . . . . . .
Maximum allowable variation between cylinders
Oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine block
Cylinder bore diameter (standard) . . . . . . . .
Maximum allowable taper and out-of-round .
.............
.............
Not available
3 0 psi
Not available
3.503 to 3.506 in
0.001 in
Cylinder head and valves
Warpage limit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum valve margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve stem-to-guide clearance . . . . . . . . . . . . . . . . . . . . . . .
Valve spring pressure
Valve closed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valveopen
Valve spring free length . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve spring installed height . . . . . . . . . . . . . . . . . . . . . . . . .
0.002 in per 6 in (0.006 in overall)
1132-in
0.001 t o 0.002 in
8 8 Ibs at 1.57 in
1 9 5 Ibs at 1.18 in
1.909 in
1 . 5 7 in
Crankshaft and connecting rods
Connecting rod journal
Diameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bearing oil clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting rod side clearance (end play). . . . . . . . . . . . . . . .
Main bearing journal diameter
1984
Journals 1, 2 and 4
Journal3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1985 and 1986 (all journals) . . . . . . . . . . . . . . . . . . . . . . .
Main bearing oil clearance . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft end play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum taper and out-of-round (all journals) . . . . . . . . . . . .
1 .999 to 1 .998 in
0.001 to 0.003 in
0.006 to 0.01 7 in
2.493 to 2.494 in
2.492 to 2.494 in
2.647 to 2.648 in
0.0016 to 0.003 in
0.002 to 0.006 in
0.001 in
Pistons and rings
Piston-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring end gap
Compression rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring (steel rail) . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring side clearance
Top compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Second compression ring. . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque specifications *
Connecting rod cap nuts. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note: Refer to Part B for additional torque specifications.
*
0.0006 to 0.0016 in
0.0098 to 0.0196 in
0.020 to 0.055 in
0.001 t o 0.0027 in
0.001 5 t o 0 . 0 0 3 7 i n
0 . 0 0 7 8 in maximum
Ft-lbs
37
70
20-1
The Motor Manual Guy
Chapter 2 Part D
2D-2
General engine overhaul procedures
lnline six-cylinder engine
General
Cylinder compression pressure
Maximum variation between cylinders
Oil pressure
A t idle ( 6 0 0 rpm)
Above 1600 rpm
Cylinder head and valves
Warpage limit.
Minimum valve margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve stem diameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve stem-to-guide clearance
Valve spring pressure
Valveopen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve closed
Valve lifter
Diameter.
Lifter-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 2 0 t o 150 psi
3 0 psi
1 3 psi
3 7 t o 7 5 psi
0.002 in per 6 in
1/32 in
0.312 i n
0.001 t o 0 . 0 0 3 in
2 0 5 t o 2 2 0 Ibs at 1.2 in
6 4 t o 7 4 Ibs at 1.625 in
0.904 to 0.9045 in
0.001 to 0.0025 in
Crankshaft and connecting rods
Connecting rod journal
Diameter.
Bearing oil clearance
Desired
Allowable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting rod side clearance (end play).
Main bearing
Journal diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bearing oil clearance
Desired
Allowable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft end play (at thrust bearing)
Maximum taper and out-of-round (all journals) . . . . . . . . . . . .
2.0934 to 2.0955 in
0.001 5 to 0.002 in
0.001 to 0.003 in
0.010 to 0.019 in
2.4996 to 2.5001 in
0.002 in
0.001 to 0.0025 in
0.001 5 to 0.0065 in
0.0005 in
Pistons and rings
Piston-to-bore clearance
Desired
Allowable
Piston ring end gap
Compression rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring (steel rails).
Piston ring side clearance
Compression rings
Desired
...........
Allowable . . . . . . . . . . . . . . . . . . . . . .
Oil control ring
Desired
Allowable
Engine block
Maximum warpage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder bore diameter (standard)
Maximum taper and out-of-round
Torque specifications
*
Main bearing cap bolts
Connecting rod cap n u t s . . . . . . . . . . . . . . . . . . . . . . . . . . . .
* Note: Refer to Part C for additional torque specifications.
General information
Included in this portion of Chapter 2 are the general overhaul procedures for the cylinder head(s) and internal engine components.
The information ranges from advice concerning preparation for an
overhaul and the purchase of replacement parts t o detailed, step-bystep procedures covering removal and installation of internal engine
components and the inspection of parts.
The following Sections have been written based o n the assumption
that the engine has been removed from the vehicle. For information
concerning in-vehicle engine repair, as well as removal and installation
of the external components necessary for the overhaul, see Part A,
B or C of this Chapter and Section 7 of this Part.
The Specifications included in this Part are only those necessary for
0.001 2 to 0.0013 in
0.0009 to 0.0017 in
0.010 to 0.020 in
0.010 to 0.025 in
0.0017 in
0.0017 to 0.0032 in
0.003 in
0.001 to 0.008 in
0.002 in per 6 in (0.008 in overall)
3.8751 t o 3.8775 in
0.001 in
Ft-lbs
80
33
the inspection and overhaul procedures which follow. Refer t o Parts
A, B and C for additional Specifications.
--
2 Engine overhaul - general information
Refer to illustrations 2.4a and 2.4b
It's not always easy t o determine when, or if, an engine should be
completely overhauled, as a number o f factors must be considered.
High mileage is not necessarily an indication that an overhaul is
needed, while l o w mileage doesn't preclude the need for an overhaul.
Frequency of servicing is probably the most important consideration.
A n engine that's had reguiar and frequent oil and filter changes, as
well as other required maintenance, will most likely give many thou-
The Motor Manual Guy
Chapter 2 Part D
2.4a
General engine overhaul procedures
Remove the oil pressure sending unit (arrow)
2.4b
2D-3
...
and connect a gauge to check oil pressure
- the sending unit is
located near the oil filter on all models
(inline six-cylinder engine shown)
sands of miles of reliable service. Conversely, a neglected engine may
require an overhaul very early in its life.
Excessive oil consumption is an indication that piston rings, valve
seals and/or valve guides are in need of attention. Make sure that oil
leaks aren't responsible before deciding that the rings andior guides
are bad. Perform a cylinder compression check to determine the extent of the work required (see Section 3).
Check the oil pressure with a gauge installed in place of the oil
pressure sending unit (see illustrations) and compare it to the Specifications. If it's extremely low, the bearings and/or oil pump are probably
worn out.
Loss of power, rough running, knocking or metallic engine noises,
excessive valve train noise and high fuel consumption rates may also
point to the need for an overhaul, especially if they're all present at
the same time. If a complete tune-up doesn't remedy the situation,
major mechanical work is the only solution.
An engine overhaul involves restoring the internal parts to the specifications of a new engine. During an overhaul, the piston rings are replaced and the cylinder walls are reconditioned (rebored and/or honed).
If a rebore is done by an automotive machine shop, new oversize
pistons will also be installed. The main bearings, connecting rod bearings and camshaft bearings are generally replaced with new ones and,
if necessary, the crankshaft may be reground to restore the journals.
Generally, the valves are serviced as well, since they're usually in lessthan-perfect condition at this point. While the engine is being overhauled, other components, such as the distributor, starter and alternator, can be rebuilt as well. The end result should be a like new engine
that will give many thousands of trouble free miles. Note: Critical cooling system components such as the hoses, drivebelts, thermostat and
water pump MUST be replaced with new parts when an engine is
overhauled. The radiator should be checked carefully to ensure that
i t isn't clogged or leaking (see Chapter 3). Also, we don't recommend
overhauling the oil pump - always install a new one when an engine
is rebuilt.
Before beginning the engine overhaul, read through the entire procedure to familiarize yourself with the scope and requirements of the
job. Overhauling an engine isn't difficult if you have the right equipment
and follow the instructions carefully, but it is time consuming. Plan
on the vehicle being tied up for a minimum of t w o weeks, especially
if parts must be taken t o an automotive machine shop for repair or
reconditioning. Check on availability of parts and make sure that any
necessary special tools and equipment are obtained in advance. Most
work can be done with typical hand tools, although a number of precision measuring tools are required for inspecting parts t o determine if
they must be replaced. Often an automotive machine shop will handle
the inspection of parts and offer advice concerning reconditioning and
replacement. Note: Always wait until the engine has been completely
disassembled and all components, especially the engine block, have
been inspected before deciding what service and repair operations must
be performed by an automotive machine shop. Since the block's condition will be the major factor to consider when determining whether
to overhaul the original engine or buy a rebuilt one, never purchase
parts or have machine work done on other components until the block
has been thoroughly inspected. As a general rule, time is the primary
cost of an overhaul, so it doesn't pay to install worn or substandard
parts.
As a final note, to ensure maximum life and minimum trouble from
a rebuilt engine, everything must be assembled with care in a spotlessly
clean environment.
3 Cylinder compression check
Refer to illustration 3.6
1
A compression check will tell you what mechanical condition the
upper end (pistons, rings, valves, head gaskets) of your engine is in.
Specifically, it can tell you if the compression is down due to leakage
caused by worn piston rings, defective valves and seats or a blown
head gasket. Note: The engine must be at normal operating temperature
and the battery must be fully charged for this check. Also, if the engine
is equipped with a carburetor, the choke valve must be all the way
open to get an accurate compression reading (if the engine's warm,
the choke should be open).
2 Begin by cleaning the area around the spark plugs before you
remove them (compressed air should be used, if available, otherwise
a small brush or even a bicycle tire pump will work). The idea is to
prevent dirt from getting into the cylinders as the compression check
is being done.
3 Remove all of the spark plugs from the engine (see Chapter 1 ).
4 Block the throttle wide open.
5 Detach the coil wire from the center of the distributor cap and
ground it on the engine block. Use a jumper wire with alligator clips
on each end to ensure a good ground. On fuel-injected vehicles, the
fuel pump circuit should also be disabled (see Chapter 4).
6 Install the compression gauge in the number one spark plug hole
(see illustration).
3.6 A compression gauge with a threaded fitting for the
spark plug hole is preferred over the type that requires
hand pressure to maintain the seal
2D
The Motor Manual Guy
2D-4
Chapter 2 Part D General engine overhaul procedures
7
Crank the engine over at least seven compression strokes and
watch the gauge. The compression should build up quickly in a healthy
engine. Low compression on the first stroke, followed by gradually increasing pressure on successive strokes, indicates worn piston rings.
A low compression reading on the first stroke, which doesn't build up
during successive strokes, indicates leaking valves or a blown head
gasket (a cracked head could also be the cause). Deposits on the undersides of the valve heads can also cause low compression. Record the
highest gauge reading obtained.
8 Repeat the procedure for the remaining cylinders and compare the
results to the Specifications.
9 Add some engine oil (about three squirts from a plunger-type oil
can) to each cylinder, through the spark plug hole, and repeat the test.
1 0 If the compression increases after the oil is added, the piston rings
are definitely worn. If the compression doesn't increase significantly,
the leakage is occurring at the valves or head gasket. Leakage past
the valves may be caused by burned valve seats and/or faces or
warped, cracked or bent valves.
1 1 If t w o adjacent cylinders have equally low compression, there's
a strong possibility that the head gasket between them is blown. The
appearance of coolant in the combustion chambers or the crankcase
would verify this condition.
12 If one cylinder is about 2 0 percent lower than the others, and the
engine has a slightly rough idle, a worn exhaust lobe on the camshaft
could be the cause.
1 3 If the compression is unusually high, the combustion chambers
are probably coated with carbon deposits. If that's the case, the cylinder
head(s) should be removed and decarbonized.
1 4 If compression is way down or varies greatly between cylinders,
it would be a good idea to have a leak-down test performed by an
automotive repair shop. This test will pinpoint exactly where the leakage
is occurring and how severe it is.
5
Engine
- removal and installation
Refer to illustrations 5.5a, 5.5b, 5.5c, 5. 1 1, 5. 12, 5.20, 5.24a
and 5.24b
Warning: The air conditioning system is under high pressure! Have a
dealer service department or service station discharge the system
before disconnecting any system hoses or fittings.
Removal
1 Refer t o Chapter 4 and relieve the fuel system pressure (fuelinjected vehicles only), then disconnect the negative cable from the
battery.
2 Cover the fenders and cowl and remove the hood (see Chapter 11 ).
Special pads are available to protect the fenders, but an old bedspread
or blanket will also work.
3 Remove the air cleaner assembly (see Chapter 4).
4 Drain the cooling system (see Chapter 1).
5 Label the vacuum lines, emissions system hoses, wiring connectors,
ground strap and fuel lines, to ensure correct reinstallation (see illustration), then detach them (see illustrations). If there's any possibility of
4 Engine removal - methods and precautions
If you've decided that an engine must be removed for overhaul or
major repair work, several preliminary steps should be taken.
Locating a suitable place to work is extremely important. Adequate
work space, along with storage space for the vehicle, will be needed.
If a shop or garage isn't available, at the very least a flat, level, clean
work surface made of concrete or asphalt is required.
Cleaning the engine compartment and engine before beginning the
removal procedure will help keep your tools and your hands clean.
An engine hoist or A-frame will also be necessary. Make sure the
equipment is rated in excess of the combined weight of the engine
and accessories. Safety is of primary importance, considering the potential hazards involved i n lifting the engine out of the vehicle.
If the engine is being removed by a novice, a helper should be
available. Advice and aid from someone more experienced would also
be helpful. There are many instances when one person cannot simultaneously perform all of the operations required when lifting the engine
out of the vehicle.
Plan the operation ahead of time. Arrange for or obtain all of the tools
and equipment you'll need prior to beginning the job. Some of the equipment necessary to perform engine removal and installation safely and
with relative ease are (in addition to an engine hoist) a heavy duty floor
jack, complete sets of wrenches and sockets as described in the front
of this manual, wooden blocks and plenty of rags and cleaning solvent
for mopping up spilled oil, coolant and gasoline. If the hoist must be
rented, make sure that you arrange for it in advance and perform all
of the operations possible without it beforehand. This will save you
money and time.
Plan for the vehicle to be out of use for quite a while. A machine
shop will be required to perform some of the work which the do-ityourselfer can't accomplish without special equipment. These shops
often have a busy schedule, so it would be a good idea to consult them
before removing the engine in order to accurately estimate the amount
of time required to rebuild or repair components that may need work.
Always be extremely careful when removing and installing the
engine. Serious injury can result from careless actions. Plan ahead, take
your time and a job of this nature, although major, can be accomplished
successfully.
5.5a
Label both ends of each wire before unplugging
the connector
confusion, make a sketch of the engine compartment and clearly label
the lines, hoses and wires.
6 Label and detach all coolant hoses from the engine.
7 Remove the cooling fan, shroud and radiator (see Chapter 3).
8 Remove the drivebelt(s) (see Chapter 1 ).
9 Warning: Gasoline is extremely flammable, so extra precautions
must be taken when working on any part of the fuel system. DO NOT
smoke or allow open flames or bare light bulbs near the vehicle. Also,
don't work in a garage if a natural gas appliance with a pilot light is
present. Disconnect the fuel lines running from the engine t o the chassis
(see Chapter 4). Plug or cap all open fittings/lines.
1 0 Disconnect the throttle linkage (and TV linkage/cruise control cable,
if equipped) from the engine (see Chapter 4).
11 On power steering equipped vehicles, unbolt the power steering
pump (see Chapter 10). Leave the lineslhoses attached (see illustration)
and make sure the pump is kept in an upright position in the engine
compartment (use wire or rope to restrain it out of the way).
12 On air conditioned vehicles, unbolt the compressor (see Chapter 3)
and set it aside. Do not disconnect the hoses (see illustration).
13 Drain the engine oil (see Chapter 1) and remove the oil filter.
1 4 Remove the starter motor (see Chapter 5).
1 5 Remove the alternator (see Chapter 5).
The Motor Manual Guy
Chapter 2 Part D
5.56
General engine overhaul procedures
Remove the attaching screw and unplug the firewall
electrical connector
5.5c Remove the nut on the engine stud and disconnect
the ground strap (arrow)
16 Unbolt the exhaust system from the engine (see Chapter 4).
17 If you're working on a vehicle with an automatic transmission, refer
to Chapter 7 and remove the torque converter-to-driveplate fasteners.
18 Support the transmission with a jack. Position a block of wood
between the jack and transmission to prevent damage to the transmission. Special transmission jacks with safety chains are available - use
one if possible.
19 Attach an engine sling or a length of chain to the lifting brackets
on the engine.
20 Roll the hoist into position and connect the sling to it (see illustration). Take up the slack in the sling or chain, but don't lift the engine.
Warning: DO NOT place any part of your body under the engine when
it's supported only by a hoist or other lifting device.
21 Remove the transmission-to-engine block bolts.
22 Remove the engine mount-to-frame bolts.
23 Recheck to be sure nothing is still connecting the engine to the
transmission or vehicle. Disconnect anything still remaining.
24 Raise the engine slightly. Carefully work it forward t o separate it
from the transmission. If you're working on a vehicle with an automatic
transmission, be sure the torque converter stays in the transmission
(clamp a pair of vise-grips t o the housing to keep the converter from
sliding out). If you're working on a vehicle with a manual transmission, the input shaft must be completely disengaged from the clutch.
5.12
Unbolt the air conditioning compressor and set it out
of the way
2D-5
ao
5.1 1 Set the power steering pump aside with the lines
still connected - be sure it's upright so fluid won't spill
5.20
Connect the lifting sling to the hoist and take up the slack
The Motor Manual Guy
Chapter 2 Part D
2D-6
5.24a
General engine overhaul procedures
5.24b
Pull the engine forward as far as possible t o clear
the transmission, . . .
...
then lift the engine high enough to clear the body
Slowly raise the engine out of the engine compartment (see illustrations). Check carefully to make sure nothing is hanging up.
25 Remove the flywheelidriveplate and mount the engine on an engine
stand.
lnstallatian
26 Check the engine and transmission mounts. If they're worn or
damaged, replace them.
27 If you're working on a vehicle with a manual transmission, install
the clutch and pressure plate (Chapter 7). Now is a good time to install
a new clutch.
28 Carefully lower the engine into the engine compartment - make
sure the engine mounts line up.
29 If you're working on a vehicle with an automatic transmission,
guide the torque converter into the crankshaft following the procedure
outlined in Chapter 7.
3 0 If you're working on a vehicle with a manual transmission, apply
a dab of high-temperature grease to the input shaft and guide it into
the crankshaft pilot bearing until the bellhousing is flush with the engine
block.
31 Install the transmission-to-engine bolts and tighten them securely.
Caution: DO NOT use the bolts to force the transmission and engine
together!
32 Reinstall the remaining components in the reverse order of removal.
3 3 Add coolant, oil, power steering and transmission fluid as needed.
3 4 Run the engine and check for leaks and proper operation of all accessories, then install the hood and test drive the vehicle.
3 5 Have the air conditioning system recharged and leak tested.
7.3b
lnline six-cylinder engine
left side view
7.3a
6
lnline six-cylinder engine - front view
Engine rebuilding alternatives
The do-it-yourselfer is faced with a number of options when performing an engine overhaul. The decision to replace the engine block,
piston/connecting rod assemblies and crankshaft depends on a number
of factors, with the number one consideration being the condition of
7.3c
lnline six-cylinder engine
right side view
The Motor Manual Guy
Chapter 2 Part D
General engine overhaul procedures
~I, BJ:;·
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2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
2D-7
Internal engine components - exploded view
(inline six-cylinder engine)
Engine oil dipstick and tube
Oil filter b y-pass plug
Build date code location
Ring set
Piston
Pin set
Plug
Engine block
Oil channel plug
Camshaft
Connecting rod
Pin
Camshaft sprocket
Keys
Washer
Timing chain
Oil shedder (slinger)
Crankshaft sprocket
Crankshaft
Connecting rod bearing
Connecting rod
bearing cap
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
Main bearings
Vibration damper pulley
Washer
Vibration damper
Seal
Timing chain cover
Gasket
Main bearing cap (rear)
Main bearing cap seal
kit (rear)
Pilot bushing (with
manual transmission)
Bushing oil wick (with
manual transmission)
Flywheel and ring gear
(with manual transmission)
Bearing set
Dowel
Plug
2D
27
25
t h e block. Other considerations are cost, access t o machine shop
facilities, parts availability, time required t o complete the project and the
extent of prior mechanical experience on the part of the do-it-yourselfer.
Some of the rebuilding alternatives include:
Individual parts - If the inspection procedures reveal that the engine
block and most engine components are in reusable condition, purchasing individual parts may be the most economical alternative. The block,
crankshaft and pistonlconnecting rod assemblies should all be inspected
carefully. Even if the block shows little wear, the cylinder bores should
be surface honed.
Short block - A short block consists of an engine block with a crankshaft, camshaft and pistonlconnecting rod assemblies already installed.
All new bearings are incorporated and all clearances will be correct.
The existing valve train components, cylinder head(s) and external parts
can be bolted t o the short block w i t h little or no machine shop work
necessary.
Long block - A long block consists of a short block plus an oil pump,
oil pan, cylinder head(s), rocker arm cover(s) and valve train components, timing sprockets and chain or gears and timing cover. All components are installed w i t h new bearings, seals and gaskets incorporated
throughout. The installation of manifolds and external parts is all that's
necessary.
Give careful thought t o which alternative is best for you and discuss
the situation w i t h local automotive machine shops, auto parts dealers
and experienced rebuilders before ordering or purchasing replacement
parts.
-
7
Engine overhaul - disassembly sequence
Refer t o illustrations 7.3a, 7.3b, 7.3c and 7.5
It's much easier t o disassemble and work on the engine if it's
mounted on a portable engine stand. A stand can often be rented quite
cheaply from an equipment rental yard. Before t h e engine is mounted
on a stand, the flywheel/driveplate should be removed from the engine.
2 If a stand isn't available, it's possible t o disassemble the engine
w i t h it blocked up on the floor. Be extra careful not t o tip or drop the
engine w h e n working without a stand.
3 If you're going t o obtain a rebuilt engine, all external components
must come off first (see illustrations),t o be transferred t o the replacement engine, just as they will if you're doing a complete engine overhaul
yourself. These include:
Alternator and brackets
Emissions control components
Distributor, spark plug wires and spark plugs
Thermostat and housing cover
Water pump
Fuel injection components or carburetor
Intake/exhaust manifolds
Oil filter
Engine mounts
Clutch and flywheel/driveplate
Engine rear plate
Note: When removing the external components from the engine, pay
close attention t o details that may be helpful or important during installation. Note the installed position o f gaskets, seals, spacers, pins,
brackets, washers, bolts and other small items.
4 If you're obtaining a short block, which consists of the engine
block, crankshaft, pistons and connecting rods all assembled, then the
cylinder head(s), oil pan and oil pump will have t o be removed as well.
See Engine rebuilding alternatives for additional information regarding
t h e different possibilities t o be considered.
5 If you're planning a complete overhaul, the engine must be disassembled and the internal components (see illustration) removed in the
following order:
Rocker arm cover(s)
Intake and exhaust manifolds
Rocker arms and pushrods
Cylinder head(s)
Valve lifters
Timing cover
Timing chain and sprockets
Camshaft
Oil pan
Oil pump
Piston/connecting rod assemblies
Crankshaft and main bearings
The Motor Manual Guy
2D-8
Chapter 2 Part D
General engine overhaul procedures
6 Before beginning the disassembly and overhaul procedures, make
sure the following items are available. Also, refer to Engine overhaul reassembly sequence for a list of tools and materials needed for engine
reassembly.
Common hand tools
Small cardboard boxes or plastic bags for storing parts
Gasket scraper
Ridge reamer
Vibration damper puller
Micrometers
Telescoping gauges
Dial indicator set
Valve spring compressor
Cylinder surfacing hone
Piston ring groove cleaning tool
Electric dri(( motor
Tap and die set
Wire brushes
Oil gallery brushes
Cleaning solvent
8 Cylinder head - disassembly
Refer to illustrations 8.2, 8 . 3 and 8 . 4
Note: New and rebuilt cylinder heads are commonly available for most
engines a t dealerships and auto parts stores. Due to the fact that some
specialized tools are necessary for the disassembly and inspection procedures, and replacement parts may n o t b e readily available, i t may
be more practical and economical for the home mechanic t o purchase
replacement head(s} rather than taking the time to disassemble, inspect
and recondition the original(s).
1 Cylinder head disassembly involves removal of the intake and exhaust valves and related components. If they're still in place, remove
t h e rocker arm bolts or nuts, pivot and rocker arms from the cylinder
head studs. Label the parts or store them separately so they can be
reinstalled in their original locations.
2 Before the valves are removed, arrange t o label and store them,
along w i t h their related components, so they can be kept separate and
reinstalled in the same valve guides they were removed from (see illustration).
3 Compress the springs on the first valve w i t h a spring compressor
and remove the keepers (see illustration). Carefully release the valve
spring compressor and remove the retainer, the spring and the spring
seat (if used).
4 Pull the valve out of the head, then remove the oil seal from the
guide. If t h e valve binds in the guide (won't pull through), push it back
into the head and deburr the area around the keeper groove w i t h a fine
file or whetstone (see illustration).
5 Repeat the procedure for the remaining valves. Remember t o keep
all t h e parts for each valve together so they can be reinstalled tn the
same locations.
6 Once the valves and related components have been removed and
stored in an organized manner, the head should be thoroughly cleaned
and inspected. If a complete engine overhaul is being done, finish the
engine disassembly procedures before beginning the cylinder head
cleaning and inspection process.
--
9 Cylinder head
- cleaning and
inspection
Refer to illustrations 9.12, 9 . 14, 9 . ,5a, 9.15b, 9.16, 9.17, 9 . 1 8
and 9 . 1 9
1 Thorough cleaning of the cylinder head(s) and related valve train
components, followed by a detailed inspection, will enable you t o
decide how much valve service work must be done during the engine
overhaul. Note: If the engine was severely overheated, the cylinder
head is probably warped (see Step 12).
Cleaning
8.2
A small plastic bag, w i t h an appropriate label, can be
used t o store the valve train components so they can be
kept together and reinstalled in t h e correct guide
2 Scrape all traces of old gasket material and sealing compound off
the head gasket, intake manifold and exhaust manifold sealing surfaces.
Be very careful not t o gouge the cylinder head. Special gasket removal
solvents that soften gaskets and make removal much easier are
available at auto parts stores.
3 Remove all built u p scale from the coolant passages.
4 Run a stiff wire brush through the various holes t o remove deposits
8.3 Use a valve spring compressor t o compress t h e
8.4 If t h e valve w o n ' t pull through t h e guide, deburr t h e
spring, then remove t h e keepers from the valve stem
edge of t h e stem end and the area around t h e t o p of t h e
keeper groove w i t h a file
The Motor Manual Guy
Chapter 2 Part D
2D-9
General engine overhaul procedures
9.12 Check the cylinder head gasket surface for warpage
by trying t o slip a feeler gauge under the straightedge
(see the Specifications for the maximum warpage allowed
and use a feeler gauge of that thickness)
that may have formed in them.
5 Run an appropriate size tap into each of the threaded holes to
remove corrosion and thread sealant that may be present. If compressed air is available, use it t o clear the holes of debris produced
by this operation. Warning: Wear eye protection when using compressed air!
6 Clean the rocker arm pivot bolt or stud threads with a wire brush.
7 Clean the cylinder head with solvent and dry it thoroughly. Compressed air will speed the drying process and ensure that all holes and
recessed areas are clean. Note: Decarbonizing chemicals are available
and may prove very useful when cleaning cylinder heads and valve
train components. They are very caustic and should be used with caution. Be sure to follow the instructions on the container.
8 Clean the rocker arms, pivot balls or fulcrums, nuts or bolts and
pushrods with solvent and dry them thoroughly (don't mix them up
during the cleaning process). Compressed air will speed the drying process and can be used t o clean out the oil passages.
9 Clean all the valve springs, spring seats, keepers and retainers (or
rotators) with solvent and dry them thoroughly. Do the components
from one valve at a time t o avoid mixing up the parts.
10 Scrape off any heavy deposits that may have formed on the valves,
then use a motorized wire brush to remove deposits from the valve
heads and stems. Again, make sure the valves don't get mixed up.
9.14 A dial indicator can be used t o determine the valve
stem-to-guide clearance (move the valve stem as
indicated by the arrows)
Valves
15 Carefully inspect each valve for uneven wear, deformation, cracks,
pits and burned areas (see illustrations). Check the valve stem for
scuffing and galling and the neck for cracks. Rotate the valve and check
for any obvious indication that it's bent. Look for pits and excessive
wear on the end of the stem. The presence of any of these conditio ns
indicates the need for valve service by an automotive machine sho•P-
CD_
<D
<D{
Inspection
Note: Be sure to perform all o f the following inspection procedures
before concluding that machine shop work is required. Make a list of
the items that need attention.
Cylinder head
1 1 Inspect the head very carefully for cracks, evidence of coolant
leakage and other damage. If cracks are found, check with an automotive machine shop concerning repair. If repair isn't possible, a new
cylinder head should be obtained.
12 Using a straightedge and feeler gauge, check the head gasket
mating surface for warpage (see illustration). If the warpage exceeds
the specified limit, it can be resurfaced at an automotive machine shop.
Note: If the V6 engine heads are resurfaced, the intake manifold flanges
will also require machining.
13 Examine the valve seats in each of the combustion chambers. If
they're pitted, cracked or burned, the head will require valve service
that's beyond the scope of the home mechanic.
14 Check the valve stem-to-guide clearance by measuring the lateral
movement of the valve stem with a dial indicator attached securely
to the head (see illustration). The valve must be in the guide and approximately 1 /1 6-inch off the seat. The total valve stem movement indicated
by the gauge needle must be divided by t w o to obtain the actual
clearance. After this is done, if there's still some doubt regarding the
condition of the valve guides they should be checked by an automotive
machine shop (the cost should be minimal).
NEW VALVE
9.15a
WORN VALVE
Check for valve wear at the points shown here
1 Valve tip
2 Keeper groove
3 Stem (least worn area)
9.15b
4 Stem (most worn areal
5 Valve face
6 Margin
Valve stem tip wear patterns
Proper tip pattern {rotator
functioning properly)
2 No rotation pattern (replace
rotator and check rotation)
3 Partial rotation pattern
(replace rotator and
check rotation)
2D
The Motor Manual Guy
Chapter 2 Part D
2D-10
General engine overhaul procedures
VALVE MARGIN WIDTH
NO MARGIN
9.16 The margin width on each valve must be as
specified (if no margin exists, the valve cannnot be reused)
9.17 Measure the free length of each valve spring with a
dial or vernier caliper
16 Measure the margin width on each valve (see illustration). Any
valve with a margin narrower than specified will have to be replaced
with a new one.
Valve components
17 Check each valve spring for wear (on the ends) and pits. Measure
the free length and compare it t o the Specifications (see illustration).
Any springs that are shorter than specified have sagged and should
not be reused. The tension of all springs should be checked with a
special fixture before deciding that they're suitable for use in a rebuilt
engine (take the springs to an automotive machine shop for this check).
18 Stand each spring on a flat surface and check it for squareness
(see illustration). If any of the springs are distorted or sagged, replace
all of them with new parts.
19 Check the spring retainers (or rotators) and keepers for obvious
wear and cracks. Any questionable parts should be replaced with new
ones, as extensive damage will occur if they fail during engine operation. Make sure the rotators operate smoothly with no binding or excessive play (see illustration).
Rocker arm components
2 0 Check the rocker arm faces (the areas that contact the pushrod
ends and valve stems) for pits, wear, galling, score marks and rough
spots. Check the rocker arm pivot contact areas and pivot balls or
fulcrums as well. Look for cracks in each rocker arm and nut or bolt.
21 Inspect the pushrod ends for scuffing and excessive wear. Roll
each pushrod on a flat surface, like a piece of plate glass, to determine
if it's bent.
22 Check the rocker arm bolt holes or studs in the cylinder heads for
damaged threads and secure installation.
23 Any damaged or excessively worn parts must be replaced with
new ones.
24 If the inspection process indicates that the valve components are
in generally poor condition and worn beyond the limits specified, which
is usually the case in an engine that's being overhauled, reassemble
the valves in the cylinder head and refer to Section 10 for valve servicing
recommendations.
10
Valves
9.18 Check each valve spring for squareness
servicing
1 Because of the complex nature of the job and the special tools and
equipment needed, servicing of the valves, the valve seats and the
valve guides, commonly known as a valve job, should be done by a
professional.
2 The home mechanic can remove and disassemble the head(s), do
the initial cleaning and inspection, then reassemble and deliver it (or
them) to a dealer service department or an automotive machine shop
for the actual service work. Doing the inspection will enable you to
see what condition the head and valvetrain components are in and will
ensure that you know what work and new parts are required when
dealing with an automotive machine shop.
3 The dealer service department, or automotive machine shop, will
remove the valves and springs, recondition or replace the valves and
valve seats, recondition the valve guides, check and replace the valve
9.19 The exhaust valve rotators can be checked by
turning the inner and outer sections in opposite directions
t o check for smooth movement and excessive play
springs, spring retainers or rotators and keepers (as necessary), replace
the valve seals with new ones, reassemble the valve components and
make sure the installed spring height is correct. The cylinder head
gasket surface will also be resurfaced if it's warped.
4 After the valve job has been performed by a professional, the head
will be in like-new condition. When the head is returned, be sure to
clean it again before installation on the engine to remove any metal
particles and abrasive grit that may still be present from the valve service or head resurfacing operations. Use compressed air, if available,
to blow out all the oil holes and passages.
The Motor Manual Guy
Chapter 2 Part D
11.3
General engine overhaul procedures
2D-I 1
Make sure the new valve stem seals are seated
against the tops of the valve guides
1 Valve seated in tool
be sure
2 End of valve stem
to deburr this area before
installing the seal
3 Seal
4 Valve seal installation tool
(if you don't have this tool, a
deep socket also will work)
11.5a
00
_5
~
00
~
Valves and related components for inline four and
six-cylinder engines
exploded view
I Keepers
2 Retainers
3 Springs
~
:~
4 Umbrella-type oil seals
5 Valves
2D
1-4-1
~1
B
A
1 1.5b V 6 engine valves and related
components - exploded view
A Intake valve
B Exhaust valve
11
I Unbrella seal (intake only)
2 Oil shedder (exhaust only)
3 Rotator/retainer
4 Spring
5 O-ring seal
Cylinder head - reassembly
Refer to illustrations 1 1.3, 1 1.5a, 11.5b, 1 1.5c, I 1.6a, 11.6b, 1 1.8
and 11.9
1 Regardless of whether or not a head was sent t o an automotive
repair shop for valve servicing, make sure it's clean before beginning
reassembly.
2 If a head was sent out for valve servicing, the valves and related
components will already be in place. Begin the reassembly procedure
with Step 8.
3 Install new seals on each of the intake valve guides. Using a hammer and a deep socket or seal installation tool, gently tap each seal
into place until it's completely seated on the guide (see illustration).
Don't twist or cock the seals during installation or they won't seal properly on the valve stems. The umbrella-type seals (if used) are installed
over the valves after the valves are in place.
4 Beginning at one end of the head, lubricate and install the first
valve. Apply moly-base grease or clean engine oil t o the valve stem.
5 Drop the spring seat or shim(s) over the valve guide and set the
valve springs, shield and retainer (or rotator) in place (see illustrations).
6 Compress the springs with a valve spring compressor and carefully
install the O-ring oil seal ( V 6 only) in the lower groove of the valve
stem. Make sure the seal isn't twisted
it must lie perfectly flat in
the groove (see illustration). Position the keepers in the upper groove,
1 1.5c Later model four-cylinder engines have
progressively wound valve springs - install them with the
closely wound coils toward the cylinder head
Make sure the O-ring seal (arrow) under the
retainer is seated in the groove and not twisted before
installing the keepers (V6 engine only)
The Motor Manual Guy
2D-12
Chapter 2 Part D
General engine overhaul procedures
11.6b Apply a small dab of grease t o each keeper as
shown here before installation
it will hold them i n place
on the valve stem as the spring is released
11.8
11.9 Be sure t o check the valve spring installed height
(the distance from the top of the seat/shims t o the top of
the shield or the bottom of the retainer)
A special adapter and vacuum pump are required t o
check the O-ring valve stem seals for leaks
then slowly release the compressor and make sure the keepers seat
properly. Apply a small dab of grease to each keeper to hold it in place
if necessary (see illustration).
7 Repeat the procedure for the remaining valves. Be sure to return
the components to their original locations - don't mix them up!
8 On V 6 engines, when all the valves are in place in both heads, the
valve stem O-ring seals must be checked to make sure they don't leak.
This procedure requires a vacuum pump and special adapter (tool no.
J-23994), so it may be a good idea t o have it done by a dealer service
department, repair shop or automotive machine shop. The adapter is
positioned on each valve retainer or rotator and vacuum is applied with
the hand pump (see illustration). If the vacuum can't be maintained,
the seal is leaking and must be checked/replaced before the head is
installed on the engine.
9 Check the installed valve spring height with a ruler graduated in
1132-inch increments or a dial caliper. If the head was sent out for service work, the installed height should be correct (but don't automatically
assume that it is). The measurement is taken from the top of each spring
seat or shim(s) to the top of the oil shield (or the bottom of the retainer1
rotator, the t w o points are the same) (see illustration). If the height
is greater than specified, shims can be added under the springs to correct it. Caution: Don't, under any circumstances, shim the springs to
the point where the installed height is less than specified.
10 Apply moly-base grease t o the rocker arm faces and the pivots,
then install the rocker arms and pivots on the cylinder head. Thread
the bolts/nuts on three or four turns only (when the heads are installed
on a V 6 engine, the nuts will be tightened following a specific procedure).
12 Pistonslconnecting rods - removal
12.1
A ridge reamer is required t o remove the ridge from
the top of each cylinder - do this before
removing the pistons!
Refer to illustrations 12.1, 12.3 and 12.6
Note: Prior to removing the piston/connecting rod assemblies, remove
the cylinder head(s), the oil pan and the oil pump by referring to the
appropriate Sections in Chapter 2.
1 Use your fingernail to feel if a ridge has formed at the upper limit
of ring travel (about 114-inch down from the top of each cylinder). If
carbon deposits or cylinder wear have produced ridges, they must be
completely removed with a special tool (see illustration). Follow the
manufacturer's instructions provided with the tool. Failure to remove
the ridges before attempting to remove the piston/connecting rod
assemblies may result in piston breakage.
2 After the cylinder ridges have been removed, turn the engine upside-down so the crankshaft is facing up.
3 Before the connecting rods are removed, check the end play with
feeler gauges. Slide them between the first connecting rod and the
crankshaft throw until the play is removed (see illustration). The end
play is equal to the thickness of the feeler gauge(s). If the end play
The Motor Manual Guy
Chapter 2 Part D
12.3
General engine overhaul procedures
Check the connecting rod side clearance with a
feeler gauge as shown
exceeds the service limit, new connecting rods will be required. If new
rods (or a new crankshaft) are installed, the end play may fall under
the specified minimum (if it does, the rods will have to be machined
to restore it - consult an automotive machine shop for advice if
necessary). Repeat the procedure for the remaining connecting rods.
4 Check the connecting rods and caps for identification marks. If
they aren't plainly marked, use a small center punch to make the appropriate number of indentations on each rod and cap ( 1' 2, 3, etc.,
depending on the engine type and cylinder they're associated with).
5 Loosen each of the connecting rod cap nuts 112-turn at a time until
they can be removed by hand. Remove the number one connecting
rod cap and bearing insert. Don't drop the bearing insert out of the cap.
6 Slip a short length of plastic or rubber hose over each connecting
rod cap bolt to protect the crankshaft journal and cylinder wall as the
piston is removed (see illustration).
7 Remove the bearing insert and push the connecting rodlpiston
assembly out through the top of the engine. Use a wooden hammer
handle to push on the upper bearing surface in the connecting rod.
If resistance is felt, double-check t o make sure that all of the ridge was
removed from the cylinder.
8 Repeat the procedure for the remaining cylinders.
9 After removal, reassemble the connecting rod caps and bearing
inserts in their respective connecting rods and install the cap nuts finger
tight. Leaving the old bearing inserts in place until reassembly will help
prevent the connecting rod bearing surfaces from being accidentally
nicked or gouged.
10 Don't separate the pistons from the connecting rods (see Section 17 for additional information).
2D-13
12.6 To prevent damage t o the crankshaft journals and
cylinder walls, slip sections of hose over the rod bolts
before removing the pistons
2D
BEARING
13.1
Checking crankshaft end play with a dial indicator
13 Crankshaft - removal
Refer to illustrations 13. 1, 13.3, 13.4a, 13.4b and 13.4c
Note: The crankshaft can be removed only after the engine has been
removed from the vehicle. It's assumed that the flywheel or driveplate,
vibration damper, timing chain, oil pan, oil pump and piston/connecting
rod assemblies have already been removed.
1 Before the crankshaft is removed, check the end play. Mount a
dial indicator with the stem in line with the crankshaft and just touching
one of the crank throws (see illustration).
2 Push the crankshaft all the way to the rear and zero the dial indicator. Next, pry the crankshaft to the front as far as possible and check
the reading on the dial indicator. The distance that it moves is the end
play. If it's greater than specified, check the crankshaft thrust surfaces
for wear. If no wear is evident, new main bearings should correct the
end play.
3 If a dial indicator isn't available, feeler gauges can be used. Gently
pry or push the crankshaft all the way to the front of the engine. Slip
feeler gauges between the crankshaft and the front face of the thrust
main bearing t o determine the clearance (see illustration).
13.3 Checking crankshaft end play with a feeler gauge
The Motor Manual Guy
2D-14
Chapter 2 Part D
General engine overhaul procedures
13.4a Use a center punch or number stamping dies t o
mark the main bearing caps t o ensure that they're
reinstalled in their original locations on the block
(make the punch marks near one of the bolt heads)
13.4b Mark the caps in order from the front of the engine
t o the rear (one mark for the front cap, t w o for the second
one and so on) - the rear cap doesn't have t o be marked
since it cannot be installed in any other location
4 Check the main bearing caps to see if they're marked to indicate
their locations. They should be numbered consecutively from the front
of the engine to the rear. If they aren't, mark them with number stamping dies or a center punch (see illustrations). Main bearing caps generally have a cast-in arrow, which points to the front of the engine (see
illustration). Loosen the main bearing cap bolts 114-turn at a time each,
until they can be removed by hand. Note if any stud bolts are used
and make sure they're returned t o their original locations when the
crankshaft is reinstalled.
5 Gently tap the caps with a soft-face hammer, then separate them
from the engine block. If necessary, use the bolts as levers to remove
the caps. Try not to drop the bearing inserts if they come out with the
caps.
6 Carefully lift the crankshaft out of the engine. It may be a good
idea to have an assistant available, since the crankshaft is quite heavy.
With the bearing inserts in place in the engine block and main bearing
caps, return the caps to their respective locations on the engine block
and tighten the bolts finger tight.
13.4c
The arrow on the main bearing cap indicates the
front of the engine
14. l a The core plugs should be removed with a puller - if
they're driven into the block, they may be impossible to retrieve
1 4 Engine block - cleaning
Refer to illustrations 14. la, 14. 1b, 14.8 and 14.10
Caution: The core plugs (also known as freeze or soft plugs} may be
difficult or impossible to retrieve if they 're driven into the block coolant
passages.
1 Drill a small hole in the center of each core plug and pull them out
with an auto body type dent puller (see illustration). On V6 engines,
also remove the rear camshaft cover plate (see illustration).
2 Using a gasket scraper, remove all traces of gasket material from
the engine block. Be very careful not to nick or gouge the gasket sealing
surfaces.
3 Remove the main bearing caps and separate the bearing inserts
from the caps and the engine block. Tag the bearings, indicating which
cylinder they were removed from and whether they were in the cap
or the block, then set them aside.
4 Remove all of the threaded oil gallery plugs from the block. The
plugs are usually very tight - they may have to be drilled out and the
holes retapped. Use new plugs when the engine is reassembled.
5 If the engine is extremely dirty it should be taken to an automotive
machine shop to be steam cleaned or hot tanked.
6 After the block is returned, clean all oil holes and oil galleries one
more time. Brushes specifically designed for this purpose are available
at most auto parts stores. Flush the passages with warm water until
the water runs clear, dry the block thoroughly and wipe all machined
The Motor Manual Guy
'Chapter 2 Part D
b On V6 engines. remove the rear
camshaft cover plate (arrow)
General engine overhaul procedures
14.8 All bolt holes in the block particularly the main bearing cap and
head bolt holes - should be cleaned
and restored with a tap (be sure t o
remove debris from the holes after
this is done)
surfaces with a light, rust preventive oil. If you have access to compressed air, use it to speed the drying process and to blow out all the
oil holes and galleries. Warning: Wear eye protection when using compressed air!
7 If the block isn't extremely dirty or sludged up, you can do an adequate cleaning job with hot soapy water and a stiff brush. Take plenty
of time and do a thorough job. Regardless of the cleaning method used,
be sure to clean all oil holes and galleries very thoroughly, dry the block
completely and coat all machined surfaces with light oil.
8 The threaded holes in the block must be clean t o ensure accurate
torque readings during reassembly. Run the proper size tap into each
of the holes to remove rust, corrosion, thread sealant or sludge and
restore damaged threads (see illustration). If possible, use compressed
air to clear the holes of debris produced by this operation. Now is a
good time to clean the threads on the head bolts and the main bearing
cap bolts as well.
9 Reinstall the main bearing caps and tighten the bolts finger tight.
1 0 After coating the sealing surfaces of the new core plugs with Permatex no. 2 sealant, install them in the engine block (see illustration).
Make sure they're driven in straight and seated properly or leakage
could result. Special tools are available for this purpose, but a large
socket, with an outside diameter that will just slip into the core plug,
a 112-inch drive extension and a hammer will work just as well.
1 1 Apply non-hardening sealant (such as Permatex no. 2 or Teflon
pipe sealant) to the new oil gallery plugs and thread them into the holes
in the block. Make sure they're tightened securely.
12 If the engine isn't going to be reassembled right away, cover it
with a large plastic trash bag to keep it clean.
15
20-15
14.10 A large socket on an extension
can be used to drive the new soft plugs
into the bores
2D
15.4a Measure the diameter of each cylinder just under
the wear ridge (Al, at the center (Bl and at the bottom (CJ
Engine block - inspection
Refer t o illustrations 15.4a, 15.4b, 15.4c, 15.14a, 15.14b, 15. 14c
and 15.14d
1 Before the block is inspected, it should be cleaned as described
in Section 14.
2 Visually check the block for cracks, rust and corrosion. Look for
stripped threads in the threaded holes. It's also a good idea to have
the block checked for hidden cracks by an automotive machine shop
that has the special equipment to do this type of work. If defects are
found, have the block repaired, if possible, or replaced.
3 Check the cylinder bores for scuffing and scoring.
4 Measure the diameter of each cylinder at the top (just under the
ridge area), center and bottom of the cylinder bore, parallel to the
crankshaft axis (see illustrations).
The ability to "feel" when the telescoping gauge is
at the correct point will be developed over time, so work
slowly and repeat the check until you are satisfied that the
bore measurement is accurate
The Motor Manual Guy
Chapter 2 Part D
2D-16
General engine overhaul procedures
5 Next, measure each cylinder's diameter at the same three locations
across the crankshaft axis. Compare the results to the specifications.
6 If the required precision measuring tools aren't available, the pistonto-cylinder clearances can be obtained, though not quite as accurately,
using feeler gauge stock. Feeler gauge stock comes in 12-inch lengths
and various thicknesses and is generally available at auto parts stores.
7
To check the clearance, select a feeler gauge and slip it into the
cylinder along with the matching piston. The piston must be positioned
exactly as it normally would be. The feeler gauge must be between
the piston and cylinder on one of the thrust faces (90° to the piston
pin bore).
8 The piston should slip through the cylinder (with the feeler gauge
I
LETTER
CODE
OIL
FILTER
BOSS
15.4c
15.14a The engine component letter code for fourcylinder engines is located on the oil filter boss
between the fuel pump and distributor
The gauge is then measured with a micrometer t o
determine the bore size
COMPONENT
CODE
UNDERSIZE
p
One or more connecting rod bearing journals
.254 mm
(.010 in)
M
All crankshaft main bearing journals
.254 mm
(.010 in)
PM
All crankshaft main bearing journals and one or more
connecting rod journals
.254 mm
(.010 in)
B
All cylinder bores
.254 mm
(.010 in)
C
All camshaft bearing bores
.254 mm
(.010 in)
I
15.14b Four-cylinder engine component codes
I Letter
Code
B
All cylinder bores
M
All crankshaft main bearing
journals
P
C
15.14c lnline six-cylinder component codes, (A) if any,
are stamped on the boss (B) between the ignition coil (Cl
and distributor (D)
Definition
I
All connecting rod bearing
journals
All camshaft bearing bores
I
0.01 0-inch
(0.254 mm) oversize
0.010-inch
(0.254 mm) undersize
0.010-inch
(0.254 mm) undersize
0.010-inch
(0.254 mm) oversize
I
I
EXAMPLE: The code letters PM mean that the crankshaft main
bearing journals and connecting rod journals are 0.010-inch
undersize.
15.14d
lnline six-cylinder engine component codes
II
I
I
J
The Motor Manual Guy
Chapter 2 Part D
General engine overhaul procedures
2D-17
in place) with moderate pressure.
9 If it falls through or slides through easily, the clearance is excessive
and a new piston will be required. If the piston binds at the lower end
of the cylinder and is loose toward the top, the cylinder is tapered.
If tight spots are encountered as the piston/feeler gauge is rotated in
the cylinder, the cylinder is out-of-round.
10 Repeat the procedure for the remaining pistons and cylinders.
11 If the cylinder walls are badly scuffed or scored, or if they're outof-round or tapered beyond the limits given in the specifications, have
the engine block rebored and honed at an automotive machine shop.
If a rebore is done, oversize pistons and rings will be required.
12 If the cylinders are in reasonably good condition and not worn to
the outside of the limits, and if the piston-to-cylinder clearances can
be maintained properly, then they don't have t o be rebored. Honing
is all that's necessary (see Section 16).
13 Some four-cylinder and inline six-cylinder engines are produced
with oversize or undersize components, such as oversize cylinder bores,
undersize main bearing and connecting rod journals, or oversize camshaft bearing bores.
1 4 These engines are identified by a letter code stamped on the engine
block (see illustrations).
1 6 Cylinder honing
Refer to illustrations 16.3a and 16.3b
1 Prior t o engine reassembly, the cylinder bores must be honed so
the new piston rings will seat correctly and provide the best possible
combustion chamber seal. Note: If you don't have the tools or don't
want to tackle the honing operation, most automotive machine shops
will do it for a reasonable fee.
2 Before honing the cylinders, install the main bearing caps and
tighten the bolts to the specified torque.
3 Two types of cylinder hones are commonly available
the flex
hone or "bottle brush" type and the more traditional surfacing hone
with spring-loaded stones. Both will do the job, but for the less experienced mechanic the "bottle brush" hone will probably be easier to
use. You'll also need some kerosene or honing oil, rags and an electric drill motor. Proceed as follows:
a) Mount the hone in the drill motor, compress the stones (if applicable) and slip it into the first cylinder (see illustration). Be sure
to wear safety goggles or a face shield!
b) Lubricate the cylinder with plenty of honing oil or kerosene, turn
on the drill and move the hone up-and-down in the cylinder at
a pace that will produce a fine crosshatch pattern on the cylinder
walls. Ideally, the crosshatch lines should intersect at approximately a 60° angle (see illustration). Be sure to use plenty of
lubricant and don't take off any more material than is absolutely
necessary to produce the desired finish. Note: Piston ring
manufacturers may specify a smaller crosshatch angle than the
traditional 60 0 - read and follow any instructions included with
the new rings.
c) Don't withdraw the hone from the cylinder while it's running.
Instead, shut off the drill and continue moving the hone up-anddown in the cylinder until it comes to a complete stop, then compress the stones and withdraw the hone. If you're using a "bottle
brush" type hone, stop the drill motor, then turn the chuck in
the normal direction of rotation while withdrawing the hone from
the cylinder.
d) Wipe the oil out of the cylinder and repeat the procedure for the
remainina cvlinders.
4 After the honing job is complete, chamfer the top edges of the
cylinder bores with a small file so the rings won't catch when the
pistons are installed. Be very careful not to nick the cylinder walls with
the end of the file.
5 The entire engine block must be washed again very thoroughly
with warm, soapy water t o remove all traces of the abrasive grit produced during the honing operation. Note: The bores can be considered
dampened with clean engine oil
clean when a lint-free white cloth
used to wipe them out doesn't pick up any more honing residue,
which will show up as gray areas on the cloth. Be sure to run a brush
through all oil holes and galleries and flush them with running water.
6 After rinsing, dry the block and apply a coat of light rust preventive
oil to all machined surfaces. Wrap the block in a plastic trash bag to
keep it clean and set it aside until reassembly.
16.3a
A "bottle brush" hone will produce better results if
you have never done cylinder honing before
CROSSHATCH
PATTERN
16.3b The cylinder hone should leave a smooth,
crosshatch pattern with the lines intersecting at
approximately a 60-degree angle
17
Pistonslconnecting rods - inspection
Refer to illustrations 1 7.4a, 1 7.4b, 17. 10, 17. 1 ta and 17. 1 1b
1 Before the inspection process can be carried out, the piston/connecting rod assemblies must be cleaned and the original piston rings
removed from the pistons. Note: Always use new piston rings when
the engine is reassembled.
2 Using a piston ring installation tool, carefully remove the rings from
the pistons. Be careful not to nick or gouge the pistons in the process.
3 Scrape all traces of carbon from the top of the piston. A handheld wire brush or a piece of fine emery cloth can be used once the
majority of the deposits have been scraped away. Do not, under any
circumstances, use a wire brush mounted in a drill motor to remove
deposits from the pistons. The piston material is soft and may be eroded
away by the wire brush.
4 Use a piston ring groove cleaning tool to remove carbon deposits
from the ring grooves. If a tool isn't available, a piece broken off the
old ring will do the job. Be very careful to remove only the carbon
deposits
don't remove any metal and do not nick or scratch the sides
2D
The Motor Manual Guy
2D-18
17.4a
Chapter 2 Part D
General engine overhaul procedures
The piston ring grooves can be cleaned with a
special tool, as shown here, . . .
of the ring grooves (see illustrations).
5 Once the deposits have been removed, clean the pistonlrod
assemblies with solvent and dry them with compressed air (if available).
Make sure the oil return holes in the back sides of the ring grooves
are clear.
6 If the pistons and cylinder walls aren't damaged or worn excessively, and if the engine block is not rebored, new pistons won't be
necessary. Normal piston wear appears as even vertical wear on the
piston thrust surfaces and slight looseness of the top ring in its groove.
New piston rings, however, should always be used when an engine
is rebuilt.
7 Carefully inspect each piston for cracks around the skirt, at the
pin bosses and at the ring lands.
8 Look for scoring and scuffing on the thrust faces of the skirt, holes
in the piston crown and burned areas at the edge of the crown. If the
skirt is scored or scuffed, the engine may have been suffering from
overheating and/or abnormal combustion, which caused excessively
high operating temperatures. The cooling and lubrication systems
should be checked thoroughly. A hole in the piston crown is an indication that abnormal combustion (preignition) was occurring. Burned
areas at the edge of the piston crown are usually evidence of spark
17.10
Check the ring side clearance with a feeler gauge
at several points around the groove
17.4b
...
or a section of a broken ring
knock (detonation). If any of the above problems exist, the causes must
be corrected or the damage will occur again. The causes may include
intake air leaks, incorrect fuel/air mixture, incorrect ignition timing and
EGR system malfunctions.
9 Corrosion of the piston, in the form of small pits, indicates that
coolant is leaking into the combustion chamber and/or the crankcase.
Again, the cause must be corrected or the problem may persist in the
rebuilt engine.
1 0 Measure the piston ring side clearance by laying a new piston ring
in each ring groove and slipping a feeler gauge in beside it (see illustration). Check the clearance at three or four locations around each groove.
Be sure t o use the correct ring for each groove - they are different.
If the side clearance is greater than specified, new pistons will have
to be used.
1 1 Check the piston-to-bore clearance by measuring the bore (see Section 15) and the piston diameter. Make sure the pistons and bores are
correctly matched. Measure the piston across the skirt, at a 90° angle
t o and in line with the piston pin (see illustration). Subtract the piston
diameter from the bore diameter t o obtain the clearance. If it's greater
than specified, the block will have t o be rebored and new pistons and
rings installed (see illustration).
17.1
Measure the piston diameter at a
piston pin and in line with it
angle t o the
The Motor Manual Guy
Chapter 2 Part D
2D-19
General engine overhaul procedures
2.8 LITER V-6
SERVICE PISTONS
CODE
TYPE
STD.
HI
LIMIT
.50
o.s.
S4
89.001-89.014 mm
3.5039-3.5044 in
S5
S6
S7
1
2
3
89.014-89.027 mm
89.027-89.040 mm
89.040-89.053 mm
3.5044-3.5049 in
3.5049-3.5055 in
3.5055-3.5060 in
an cn-t1·u.::1.w
on c-t,..,
.t - uv.wu
111111
v.'"'c::vo-v.;:,..:&+
89.514-89.527 mm
89.527-89.540 mm
89.540-89.553 mm
90.001-90.014 mm
90.014-90.027 mm
--------·90.027-90.040
I- · - - · - - · - ·- mm
......
Inn I'\"'",.._,.._ ,.,.,..,..
-~
90.040-90.053 mm
,, cn,,l:"
~-
I
o.s.
SIZE
I
,_I
0.040 In
17.1 1b
--
4.
~
I'\
c,,,.,. :_
1 111
3.5241-3.5246 in
3.5246-3.5251 in
3.5251-3.5257 i n
3.5435-3.5438 in
3.5438-3.5443 in
- - 3.5443-3.5448
in
-·-. ·.........
3.5448-3.5453 i.n
-·----
I
Hi-limit pistons for V6 engines are available to
compensate for slight cylinder bore wear
12 Check the piston-to-rod clearance by twisting the piston and rod
in opposite directions. Any noticeable play indicates excessive wear,
which must be corrected. The piston/connecting rod assemblies should
be taken to an automotive machine shop t o have the pistons and rods
resized and new pins installed.
13 If the pistons must be removed from the connecting rods for any
reason, they should be taken to an automotive machine shop. While
they are there have the connecting rods checked for bend and twist,
since automotive machine shops have special equipment for this purpose. Note: Unless new pistons and/or connecting rods must be installed, do not disassemble the pistons and connecting rods.
14 Check the connecting rods for cracks and other damage. Temporarily remove the rod caps, lift out the old bearing inserts, wipe the
rod and cap bearing surfaces clean and inspect them for nicks, gouges
and scratches. After checking the rods, replace the old bearings, slip
the caps into place and tighten the nuts finger tight. Note: If the engine
is being rebuilt because of a connecting rod knock, be sure to install
new rods.
18.6
Measure the diameter of each crankshaft journal at
several points to detect taper and out-of-round conditions
2D
FATIGUE FAILURE
ll\lll'ROl'EA SEATING
D!RT IMBEDDED
INTO BEARING MATERIAL
18 Crankshaft
inspection
Refer to illustration 18.6
1 Clean the crankshaft with solvent and dry it with compressed air
(if available). Be sure to clean the oil holes with a stiff brush and flush
them with solvent.
2 Check the main and connecting rod bearing journals for uneven
wear, scoring, pits and cracks.
3 Rub a penny accross each journal several times. If a journal picks
up copper from the penny, it's too rough and must be reground.
4 Remove all burrs from the crankshaft oil holes with a stone, file
or scraper.
5 Check the rest of the crankshaft for cracks and other damage. It
should be magnafluxed to reveal hidden cracks - an automotive
machine shop will handle the procedure.
6 Using a micrometer, measure the diameter of the main and connecting rod journals and compare the results to the specifications (see
illustration). By measuring the diameter at a number of points around
each journal's circumference, you'll be able to determine whether or
not the journal is out-of-round. Take the measurement at each end of
the journal, near the crank throws, to determine if the journal is tapered.
7 If the crankshaft journals are damaged, tapered, out-of-round or
worn beyond the limits given in the specifications, have the crankshaft
reground by an automotive machine shop. Be sure t o use the correct
size bearing inserts if the crankshaft is reconditioned.
8 Check the oil seal journals at each end of the crankshaft for wear
and damage. If the seal has worn a groove in the journal, or if it's nicked
or scratched, the new seal may leak when the engine is reassembled.
In some cases, an automotive machine shop may be able to repair the
SCRATCHED BY OIRT
LACK OF OIL
····,;:
i·
·7-··---
0VERLAY GONE
FROM ENTIRE SURFACE
TAl'liREO JOURNAL
19.1
RADIUS RIDE
Typical bearing failures
journal by pressing on a thin sleeve. If repair isn't feasible, a new or
different crankshaft should be installed.
9 Refer to Section 19 and examine the main and rod bearing inserts.
19 Main and connecting rod bearings - inspection
Inspection
Refer to illustration 19. 1
1 Even though the main and connecting rod bearings should be
replaced with new ones during the engine overhaul, the old bearings
should be retained for close examination, as they may reveal valuable
information about the condition of the engine (see illustration).
The Motor Manual Guy
Chapter 2 Part D General engine overhaul procedures
2D-20
related causes. Excessive heat (which thins the oil), overloading (which
squeezes the oil from the bearing face) and oil leakage or throw off
(from excessive bearing clearances, worn oil pump or high engine
speeds) all contribute to lubrication breakdown. Blocked oil passages,
which usually are the result of misaligned oil holes in a bearing shell,
will also oil starve a bearing and destroy it. When lack of lubrication
is the cause of bearing failure, the bearing material is wiped or extruded
from the steel backing of the bearing. Temperatures may increase to
the point where the steel backing turns blue from overheating.
6 Driving habits can have a definite effect on bearing life. Full throttle,
low speed operation (lugging the engine) puts very high loads on bearings, which tends t o squeeze out the oil film. These loads cause the
bearings to flex, which produces fine cracks in the bearing face (fatigue
failure). Eventually the bearing material will loosen in pieces and tear
away from the steel backing. Short trip driving leads to corrosion of
bearings because insufficient engine heat is produced t o drive off the
condensed water and corrosive gases. These products collect in the
engine oil, forming acid and sludge. As the oil is carried t o the engine
bearings, the acid attacks and corrodes the bearing material.
7 Incorrect bearing installation during engine assembly will lead to
bearing failure as well. Tight fitting bearings leave insufficient bearing
oil clearance and will result in oil starvation. Dirt or foreign particles
trapped behind a bearing insert result in high spots on the bearing which
lead to failure.
2 Bearing failure occurs because of lack of lubrication, the presence
of dirt or other foreign particles, overloading the engine and corrosion.
Regardless of the cause of bearing failure, it must be corrected before
the engine is reassembled to prevent it from happening again.
3 When examining the bearings, remove them from the engine block,
the main bearing caps, the connecting rods and the rod caps and lay
them out on a clean surface in the same general position as their location in the engine. This will enable you to match any bearing problems
with the corresponding crankshaft journal.
4 Dirt and other foreign particles get into the engine in a variety of
ways. It may be left in the engine during assembly, or it may pass
through filters or the PCV system. It may get into the oil, and from
there into the bearings. Metal chips from machining operations and
normal engine wear are often present. Abrasives are sometimes left
in engine components after reconditioning, especially when parts are
not thoroughly cleaned using the proper cleaning methods. Whatever
the source, these foreign objects often end up embedded in the soft
bearing material and are easily recognized. Large particles will not embed in the bearing and will score or gouge the bearing and journal. The
best prevention for this cause of bearing failure is to clean all parts
thoroughly and keep everything spotlessly clean during engine
assembly. Frequent and regular engine oil and filter changes are also
recommended.
5 Lack of lubrication (or lubrication breakdown) has a number of inter-
Yellow - 2.0955 to 2.0948
(53.2257 53.2079 mm) (Standard)
Orange -2.0948 to 2.0941
(53.2079 . 53.1901 mm) (0.0007 Underslze)
2.0941 to 2.0943
Black
(53.1801 to 53.1723 mm) (0.0014 Underslze)
2.0855 to 2.08-48
Red (53.9717 to 53.9539 mm) (0.010 Underslze)
;
Bearing Insert Color Code
Crankshaft Main Bearing Journal 2-3-4-5
Color Code and Diameter In
Inches (Journal Size)
Lower Insert Size
Upper Insert Size
Yellow Yellow
Black
Red -
-
-
-
.
Standard
Standard
0.001-Inch (0.025 mm) Undersize
0.010.lnch (0.254 rnm) Undersize
-
Yellow
Black
Black Red
-
-
Standard
0.001-Inch (0.025 mm) Undersize
0.001-inch (0.025 mm) Underslze
0.010.lnch (0.245 mrn) Underslze
Connecting rod bearing selection chart - four-cylinder engines
19.8a
Connecting Rod Bearing Journal
Color Code and Diameter
(Journal Size)
Bearing Insert Color Code
Lower lnsert Size
Upper lnsert Size
Yellow - Standard
Yellow - 53.2257 53.2079 mm
(2.0955 - 2.0948 in.)
(Standard)
Yellow - Standard
Orange - 53.2079 - 53.1901 mm
(2.0948 - 2.0941 in.)
(0.0007 Undersize)
Yellow
Black - 53.1901 - 53.1 723 mm
(2.0941 2.0943 in.)
(0.0014 Undersize)
Black - 0.025 mm (0.001 in.)
Undersize
Black - 0.025 mm (0.001 in.)
Undersize
Red - 53.971 7 - 53.9539 mm
(2.0855 - 2.0848 in.)
(0.010 Undersize)
Red - 0.254 mm (0.010 in.)
Undersize
Red - 0.245 mm (0.010 in.)
Undersize
19.8b
- Standard
Connecting rod bearing selection chart
Black - 0.025 mm (0.001 in.)
Undersize
- inline
six-cylinder engines
l
The Motor Manual Guy
Chapter 2 Part D
General engine overhaul procedures
Bearing selection (four and inline six-cylinder engines)
Refer to illustrations 19.Ba, 19.Bb, 19.Bc and 19.Bd
8 If you have a four or inline six-cylinder engine and the oil clearances
are incorrect (see Section 22) or you are replacing the original bearings,
refer to the accompanying charts t o select the correct new bearings
(see illustrations),
9 If the crankshaft has been reground, new undersize bearings must
be installed. Disregard steps 1 1 through 13 and consult the automotive
machine shop that reground the crankshaft. They will provide or help
you select the correct size bearings.
1 0 Regardless of how the bearing sizes are determined, use the oil
clearance measured with Plastigage (see Section 22) as a guide t o ensure the proper size bearings are installed.
Yellow
Yellow-
2.5001 to 2.4996 (Standard)
(63.5025 to 63.4698 mm)
-
Orange
2.4996 to 2.4991 (0.0005 Undersize)
(63.4898 to 63.4771 mm)
-
Black
2.4991 to 2.4966 (0.001 Underslze)
(63.4771 to 63.4644 mm)
-
Green
2.4986 to 2.4961 (0.0015 Underslze)
(63.4644 tc83.4517 mm)
-
Red
2.4901 to 2.4896 (0.010·Underslze)
(63.2485 to 63.2358 mm)
-
-
Black
I
11 Four and inline six-cylinder engines are assembled at the factory
with various sizes of color-coded bearing inserts as listed in illustrations 19.8a through 19.8d. The color code appears on the edge of the
bearing insert.
12 The journal size codes are generally painted on the adjacent cheek
toward the flanged end (rear) of the crankshaft, except for the rear
main bearing journal, which is marked on the crankshaft rear flange.
13 To obtain a select fit, upper and lower bearing inserts of different
sizes may be used as a pair, For example, a standard insert is sometimes
used in combination with a 0.001-inch undersize insert to reduce
clearance by 0.0005-inch. Caution: Never use apair o f bearing inserts
with a greater size difference than 0.001 -inch. When replacing inserts,
the odd sizedinserts must be either all on the top or all on the bottom.
Bearing ln11rt Color
_____ Code
Cyllnder Block No. 1 Main B11rlna
Bore Color Code and
Size In 1nch11 (mm)
Crankshaft No. 1 Main B11rlna
Journal Color Cod11 and
Dlamrtrr In lnch11(mm)
Yellow
-
Black
G l o w -
-
Black
Yellow
-
Yellow
-
Upper ln11rt Size
2.6910 to_2.6915
(66.3514 to 66.3641 mm)
Yellow - Standard
2.6915 to 2.6920
Yellow
- Standard
2.6910 to 2.6915
(66.3514 to 68.3641 mm)
Yellow
- Standard
2.6915 to 2.6920
(66.3461 to 66.3768 mm)
0.001-Inch
Black
Underslze (0.025 mm)
2.6910 to 2.6915
(66.3514 to 66.3641 mm)
Black
0.001-lnch
Underslze (0.025 mm)
2.6915 to 2.6920
(68.3461 to 68.3788 mm)
Black
-·--··
2.6910 to 2.6915
(66.3514 to 68.3641 mm)
Black - 0.001-lnch
Underslze - (0.025 mm)
2.6910 to 2.6915
(88.3514 to 68.3641 mm)
Red 0.010-Inch
Underslze (0.254 mm)
(68.3641 to 68.3768 mm)
-
2D-21
-
0.001-lnch
Black
Underslze (0,025 mm)
-
-
- 0.001-lnch
Underslze (0.025 mm)
-
Lower ln11rt Size
Yellow - Standard
I
I
-
Black
0,001-Inch
Underslze (0.001 mm)
-
Black - 0.001-lnch
Underslze (0,025 mm)
Black - 0.001-Inch
I Underslze
- (0.025 mm)
I
Green
-· --··
- 0.002-Inch
----···-··
I
I
I
Ii
Underslze (0.051 mm)
Green - 0.002-lnch
Underslze - (0.051 mm)
-
Red
0.010-lnch
Underslze (0.254 mm)
-
NOTE: Wlth Green and Red Coded Crankshaft Journals, Use Yellow Coded Cylinder Block Bores Only.
Crankshaft Main B11rln9 Journal 2·3·4-5
Color Code and Dlamrtrr In
lnch11 (Journal Size)
Yellow
- 2.5001 to 2.4996 (Standard)
(63.5025 to 83.4898 mm)
Orange
- 2.4996 to 2.4991 (0.0005 Underslze)
(63.4896 to 63.4771 mm)
Black
-
Green
-
Red
-
B11rtn9 ln11rt Color Code
Lowrr Insert Size
Upper Insert Size
Yellow
I
Yellow
2.4991 to 2.4988 (0.001 Underslze)
(63.4771 to 63.4844 mm)
Black
2.4986 to 2.4961 (0.0015 Underslze)
(63.4644 to 63.4517 mm)
Black
2.4901 to 2.4896 (0.010 Underslze)
(63.2485 to 63.2358 mm)
Red
- Standard
Yellow
- Standard
Black
- Standard
-
0.001-Inch Underslze (0.025mm)
-
Black
-
-
0.001-Inch Underslze (0.025 mm)
Green
- 0.002-Inch Underslze (0.051 mm)
0.010-Inch Underslze (0.054 mm)
Red
-
19.Sc Main bearing selection chart
-
-
four-cylinder engines
I
I
0.001-Inch Underslze (0.025 mm)
0.001-Inch Underslze (0.025 mm)
0.010-lnch Underslze (0.254 mm)
2D
The Motor Manual Guy
20-22------------------------------------...
I I.
.
II
I
I
II
I
Crankshaft No. 1 Main Bearing
Journal Color Code and
Diameter
-
I.
Yellow - 63.5025-63.4898 mm
(2.5001-2.4996 in.)
(Standard)
I
I
Orange - 63.4898-63.4771 mm
(2.4996-2.4991 in.)
(0.0005 Undersize)
Black - 63.4771-63.4644 mm
(2.4991-2.4986 in.)
(0.001 Undersize)
Upper Insert Size
Lower Insert Size
Yellow - 68.3514-68.3641 mm
(2.6910-2.6915 in.)
Yellow - Standard
Yellow - Standard
Black - 68.3641-68.3768 mm
12.6915-2.6920 in.)
Yellow - Standard
Black - 0.025 mm
Undersize (0.001 in.)
Yellow - 68.3514-68.3641 mm
(2.6910-2.6915 in.)
Yellow - Standard
Black - 0.025 mm
Undersize (0.001 in.)
Black - 68.3641-68.3768 mm
(2.6915-2.6920 in.)
Black - '0.025 mm
Undersize (0.001 in.)
Black 0.025 mm
Undersize (0001· in.)
Yellow - 68.3514-68.3641 mm
(2.6910-2.6915 in.)
Black 0.025 mm
Undersize (0.001 in.)
Black - 0.025 mm
Undersize (0.001 In.)
Black - 68.3641 -68.3768 mm
(2.6915-2.6920 in.)
Black - 0.025 mm
Undersize (0.001 in.)
Green - 0.051 mm
Undersize (0.002 in.)
Yellow - 68.3514-68.3641 mm
(2.6910-2.6915 in.)
Black - 0.025 mm
Undersize (0.001· in.)
I
I
Green - 63.4644-63.4517 mm
(2.4986-2.4981 in.)
(0.0015 Undersize)
I
I
I
Red - 63.2485-63.2358 mm
(2.4901-2.4986 in.)
(0.010 Undersize)
-
Yellow - 68.3514-68.3641 mm
(2.6910-2.6915 in.)
'
Red 0.254 mm
Undersize (0.010· in.)
I
I
I
I
Red - 0.254 mm
Undersize (0.010 in.)
I
-
-
Bearing Insert Color Code
Crankshaft Main Bearina Journals 2-6
Color Code and Diameter
(Journal Size)
Upper Insert Size
Lower Insert Size
Yellow - 63.5025-63.4898 mm
(2.5001-2.4996 in.)
(Standard)
Yellow - Standard
Yellow - Standard
Orange - 63.4898-63.4771 mm
(2.4996-2.4991 in.)
(0.0005 Undersize)
Yellow - Standard
Black - 0.025 mm
Undersize (0.001 in.)
Black - 63.4771-63.4644 mm
(2.4991-2.4986 in.)
(0.001 Undersize)
Black - 0.025 mm
Undersize (0.001 in.)
Black - 0.025 mm
Undersize (0.001 in.)
Green - 63.4644-63.4517 mm
(2.4986-2.4981 in.)
(0.0015 Undersize)
Black - 0.025 mm
Undersize (0.001 in.)
Green - 0.051 mm
Undersize (0.002 in.)
I
I
Red - 63.2485-63.2358 mm
(2.4901-2.4966 in.)
(0.010 Undersize)
I
Crankshaft Main Bearing Journal 7
Color Code and Diameter
(Journal Size)
I
I.
Green - 0.051 mm
Undersize (0.002 in.)
-
-
NOTE: With Green and Red Coded Crankshaft Journals, Use Yellow Coded Cylinder
- Block Bores Only.
I
-
I
I
I
II
Bearing Insert Color Code
Cylinder Block No. 1 Main Bearing
Bore Color Code and
Size
I
Red - 0.254 mm
Undersize (0.010 in.)
I
I
Bearing Insert Color Code
I
Yellow - 63.4873-63.4746 mm
(2.4995-2.4990 in.)
(Standard)
I
Red - 0.054 mm
Undersize (0.010 in.)
Upper Insert Size
Lower Insert Size
- Standard
Yellow - Standard
Yellow
I
I
Yellow - Standard
Black - 0.025 mm
Undersize (0.001 in.)
Black - 63.4619-63.4492 mm
(2.4985-2.4980 in.)
(0.001 Undersize)
Black - 0.025 mm
Undersize (0.001 in.)
Black - 0.025 mm
Undersize (0.001 in.)
Green - 63.4492-63.4365 mm
(2.4980-2.4975 in.)
(0.0015 Undersize)
Black - 0.025 mm
Undersize (0.001 in.)
Green - 0.051 mm
Undersize (0.002 in.)
Red - 63.2333-63.2206 mm
(2.4895-2.4890 in.)
(0.010 Undersize)
Red - 0.254 mm
Undersize (0.010 in.)
Red - 0.254 mm
Undersize (0.010 in.)
Orange - 63.4746-63.4619 mm
(2.4990-2.4985 in.)
0.0005 u11ut\'1t.1£t:I')
Undersize
(u.uuuo
19.8d
Main bearing selection chart
- inline
six-cylinder engines
I
The Motor Manual Guy
Chapter 2 Part D General engine overhaul proce~iures
20 Engine overhaul - reassembly sequence
Before beginning engine reassembly, make sure you have all the
necessary new parts, gaskets and seals as well as the following items
on hand:
Common hand tools
3/8-inch and 1/2-inch drive torque wrenches
Piston ring installation tool
Piston ring compressor
Vibration damper installation tool
Short lengths of rubber or plastic hose
to fit over connecting rod bolts
Plastigage
Feeler gauges
A fine-tooth file
New engine oil
Engine assembly lube or moly-base grease
Gasket sealant
Thread locking compound
2 In order to save time and avoid problems, engine reassembly must
be done in the following general order:
New camshaft bearings (must be done by automotive machine shop)
Piston rings
Crankshaft and main bearings
Piston/connecting rod assemblies
Oil pump
Camshaft and lifters
Oil pan
Timing chain and sprockets
Cylinder head(s), pushrods and rocker arms
Timing cover
Intake and exhaust manifolds
Rocker arm cover{s)
Engine rear plate
Fly wheel/drivep/ate
21 Piston rings
-
during the end gap measuremen,t a~d engine assembly.
3 Insert the top (number one) rin 9 into the first cylinder and square
it up with the cylinder walls by pushing it in with the top of the piston
(see illustration). The ring should be near ;:,':;~ bottom of the cylinder,
at the lower limit of ring travel.
4 To measure the end gap, slip feeler gauges between' th? ends of
the ring until a gauge equal to the gap width is found (see illustration).
The feeler gauge should slide between the ring ends with a slight
amount of drag. Compare the measurement t o the Specifications. If
the gap is larger or smaller than specified, double-check t o make sure
you have the correct rings before proceeding.
5 If the gap is too small, it must be enlarged or the ring ends may
come in contact with each other during engine operation, which can
cause serious damage to the engine. The end gap can be increased
by filing the ring ends very carefully with a fine file. Mount the file in
a vise equipped with soft jaws, slip the ring over the file with the ends
contacting the file face and slowly move the ring t o remove material
from the ends. When performing this operation, file only from the outside in (see illustration).
6 Excess end gap isn't critical unless it's greater than 0.040-inch.
Again, double-check to make sure you have the correct rings for your
engine.
installation
Refer to illustrations 2 1.3, 2 1.4, 2 1.5, 2 1.9a, 2 1.9b and 2 1. 12
1 Before installing the new piston rings, the ring end gaps must be
checked. It's assumed that the piston ring side clearance has been
checked and verified correct (Section 17).
2 Lay out the pistoniconnecting rod assemblies and the new ring
sets so the ring sets will be matched with the same piston and cylinder
21.4
2D-23
With the ring square i n the cylinder, measure the
end gap with a feeler gauge
21.3 When checking piston ring end gap, the ring must
be square i n the cylinder bore (this is done by pushing the
ring down with a piston as shown)
21.5 I f the end gap is too small. clamp a file i n a vise and
file the ring ends (from the outside i n only) t o enlarge the
gap slightly
2D-24
21.9a
The Motor Manual Guy
Chapter 2 Part D General engine overhaul procedures
lnstalling the spacerlexpander in the oil control
ring groove
21.9b
DO NOT use a piston ring installation tool when
installing the oil ring side rails
7
Repeat the procedure for each ring that will be installed in the first
cylinder and for each ring in the remaining cylinders. Remember to keep
rings, pistons and cylinders matched up.
8 Once the ring end gaps have been checked/corrected, the rings
can be installed on the pistons.
9 The oil control ring (lowest one on the piston) is usually installed
first. It's normally composed of three separate components. Slip the
spacer/expander into the groove (see illustration). If an anti-rotation
tang is used, make sure it's inserted into the drilled hole in the ring
groove. Next, install the lower side rail. Don't use a piston ring installation tool on the oil ring side rails, as they may be damaged. Instead,
place one end of the side rail into the groove between the spacer/
expander and the ring land, hold i t firmly in place and slide a finger
around the piston while pushing the rail into the groove (see illustration).
Next, install the upper side rail in the same manner.
1 0 After the three oil ring components have been installed, check to
make sure that both the upper and lower side rails can be turned
smoothly in the ring groove.
1 1 The number t w o (middle) ring is installed next. It's usually stamped
with a mark which must face up, toward the top of the piston. Note:
Always follow the instructions printed on the ring package or box different manufacturers may require different approaches. Do n o t mix
up the top and middle rings, as they have different cross sections.
1 2 Use a piston ring installation tool and make sure the identification
mark is facing the top of the piston, then slip the ring into the middle
groove on the piston (see illustration). Don't expand the ring any more
than necessary to slide it over the piston.
13 Install the number one (top) ring in the same manner. Make sure
the mark is facing up. Be careful not to confuse the number one and
number t w o rings.
1 4 Repeat the procedure for the remaining pistons and rings.
22
Crankshaft - installation and main
bearing oil clearance check
Refer to illustrations 22.6, 22.11, 22.15 and 22.22
1 Crankshaft installation is the first step in engine reassembly. It's
assumed at this point that the engine block and crankshaft have been
cleaned, inspected and repaired or reconditioned.
2 Position the engine with the bottom facing up.
3 Remove the main bearing cap bolts and lift out the caps. Lay them
out in the proper order t o ensure correct installation.
4 If they're still in place, remove the original bearing inserts from
the block and the main bearing caps. Wipe the bearing surfaces of the
block and caps with a clean, lint-free cloth. They must be kept spotlessly clean.
2 1 .12 Installing the compression rings with a ring
expander - the mark (arrow) must face up
Main bearing oil clearance check
5 Clean the back sides of the new main bearing inserts and lay one
in each main bearing saddle in the block. If one of the bearing inserts
from each set has a large groove in it, make sure the grooved insert
is installed in the block. Lay the other bearing from each set in the corresponding main bearing cap. Make sure the tab on the bearing insert
fits into the recess in the block or cap. Caution: The oil holes i n the
block must line up with the oilholes i n the bearing insert. Do n o t hammer the bearing into place and don't nick or gouge the bearing faces.
No lubrication should be used a t this time.
6 The flanged thrust bearing must be installed in the proper cap and
saddle. On four-cylinder engines it is number t w o (counting from the
front of the engine); on allsix-cylinder engines it's number three (see
illustration).
7 Clean the faces of the bearings in the block and the crankshaft main
bearing journals with a clean, lint-free cloth.
8 Check or clean the oil holes in the crankshaft, as any dirt here can
go only one way - straight through the new bearings.
9 Once you're certain the crankshaft is clean, carefully lay it in position i n the main bearings.
10 Before the crankshaft can be permanently installed, the main bearing oil clearance must be checked.
1 1 Cut several pieces of the appropriate size Plastigage (they must
be slightly shorter than the width of the main bearings) and place one
The Motor Manual Guy
Chapter 2 Part D General engine overhaul procedures
22.6 Be sure the thrust bearings (arrows) are installed i n
the proper location - number three (counting from the
front of the engine) on all six-cylinder engines and number
t w o on four-cylinder engines (V6 shown)
2D-25
22.1 1 Lay the Plastigage strips (arrow) on the main
bearing journals, parallel t o the crankshaft centerline
2D,
22.22 On four-cylinder and V 6 engines, apply a thin coat
of sealer t o the chamfered areas (arrows) of the rear main
bearing cap
22.15 Compare the width of the crushed Plastigage t o
the scale on the envelope t o determine the main bearing
oil clearance (always take the measurement at the widest
point of the Plastigage); be sure t o use the correct
scale - standard and metric scales are included
piece on each crankshaft main bearing journal, parallel with the journal
axis (see illustration).
12 Clean the faces of the bearings in the caps and install the caps
in their respective positions (don't mix them up) with the arrows pointing toward the front of the engine. Don't disturb the Plastigage.
1 3 Starting with the center main and working out toward the ends,
tighten the main bearing cap bolts, in three steps, to the specified
torque. Don't rotate the crankshaft at any time during this operation.
1 4 Remove the bolts and carefully lift off the main bearing caps. Keep
them in order. Don't disturb the Plastigage or rotate the crankshaft.
If any of the main bearing caps are difficult to remove, tap them gently
from side-to-side with a soft-face hammer to loosen them.
15 Compare the width of the crushed Plastigage on each journal to
the scale printed on the Plastigage envelope to obtain the main bearing
oil clearance (see illustration). Check the Specifications to make sure
it's correct.
16 If the clearance is not as specified, the bearing inserts may be the
wrong size (which means different ones will be required). Before
deciding that different inserts are needed, make sure that no dirt or
oil was between the bearing inserts and the caps or block when the
clearance was measured. If the Plastigage was wider at one end than
the other, the journal may be tapered (refer to Section 18).
17 Carefully scrape all traces of the Plastigage material off the main
bearing journals and/or the bearing faces. Use your fingernail or the
edge of a credit card - don't nick or scratch the bearing faces.
Final crankshaft installation
18 Carefully lift the crankshaft out of the engine.
1 9 Clean the bearing faces in the block, then apply a thin, uniform
layer of moly-base grease or engine assembly lube to each of the bearing
surfaces. Be sure to coat the thrust faces as well as the journal face
of the thrust bearing. On inline six-cylinder and 1984 V6 engines, install
the rear main oil seal sections in the block and rear main bearing cap
(see Section 23).
2 0 Make sure the crankshaft journals are clean, then lay the crankshaft
back in place in the block.
21 Clean the faces of the bearings in the caps, then apply lubricant
to them.
2 2 On four-cylinder and V6 engines, apply a thin coat of sealer (Loetite 51 5 or equivalent) to the chamfered area of the rear main bearing
cap (see illustration). Install the caps in their respective positions with
the arrows pointing toward the front of the engine.
23 Install the bolts.
2 4 Tighten all except the thrust bearing cap bolts t o the specified
torque (work from the center out and approach the final torque in three
steps).
25 Tighten the thrust bearing cap bolts to 10-to-1 2 ft-lbs.
26 Tap the ends of the crankshaft forward and backward with a lead
or brass hammer t o line up the main bearing and crankshaft thrust
surfaces.
The Motor Manual Guy
2D-26
Chapter 2 Part D
General engine overhaul procedures
2 7 Retighten all main bearing cap bolts t o the specified torque, starting with the center main and working out toward the ends.
2 8 On manual transmission equipped models, install a n e w pilot bearing in the end of the crankshaft (see Chapter 8).
2 9 Rotate the crankshaft a number of times by hand t o check for any
obvious binding.
3 0 The final step is t o check the crankshaft end play w i t h a feeler
gauge or a dial indicator as described in Section 13. The end play should
be correct if the crankshaft thrust faces aren't worn or damaged and
n e w bearings have been installed.
3 1 If you are working on an engine with a one-piece rear main oil seal,
refer t o Section 2 3 and install the n e w seal.
23 Rear main oil seal installation
Four-cylinder and 1985 and later V6 engines
Refer to illustration 23.3
Note: 1985 and later V6 engines with 1 1mm thick one-piece rear main
oil seals are externally identified b y an oval cast into the left rear surface
of the engine block next to the bellhousing.
1 Clean the bore i n the block/cap and the seal contact surface on
the crankshaft. Check the crankshaft surface for scratches and nicks
that could damage the new seal lip and cause oil leaks. If the crankshaft
is damaged, the only alternative is a n e w or different crankshaft.
2 Apply a light coat of engine oil or multi-purpose grease t o the outer
edge of the n e w seal. Lubricate the seal lip with moly-base grease or
engine assembly lube.
3 On V 6 engines, press the new seal into place with the special tool
(if available)
see Part B, Section 2 0 . The seal lip must face toward
the front of the engine. If the special tool isn't available or if you have
a four-cylinder engine, carefully work the seal lip over the end of the
crankshaft and tap the seal in with a hammer and punch until it's seated
in the bore (see illustration).
lips. Also,lubricate the seal lips with moly-base grease or engine
assembly lube.
1984 V6 engine
Refer to illustration 23.9
8 1 9 8 4 V 6 engines were originally equipped w i t h two-piece seals.
They have been superceded b y a specially designed one-piece seal
which slips over the end of the crankshaft and fits in the original seal
grooves. This type of seal must be installed prior t o final crankshaft
installation. A two-piece neoprene seal is available from aftermarket
manufacturers; however, this is recommended only for in-vehicle repair.
9 The replacement seal is lubricated and pre-mounted on an installation tool (see illustration). Do not remove the seal from the tool prior
t o installation.
1 0 Apply a thin coat of Loctite 51 5 sealer (or equivalent) t o the outside
diameter of the replacement seal. The sealer bead should be n o more
than 1 m m (0.040-inch) thick.
1 1 Carefully push the replacement rear main seal and the tool onto
the rear o f the crankshaft as far as possible. Position the alignment
arrow on the seal tool so it will be pointing d o w n when installed.
1 2 Align the replacement seal w i t h the seal groove in the block as
you carefully install the crankshaft. Make sure the crankshaft is properly
lubricated.
1 3 Remove the seal installation tool by rotating i t t o the left and pulling
it off the crankshaft.
1 4 Apply a 1mm (0.040-inch) bead of Loctite 5 1 5 sealer (or equivalent) t o the end surfaces of the rear main bearing cap (see illustration
23.7).Do not get any sealer on the seal lips or on the crankshaft.
1 5 Install the main bearing caps (see Section 22).
REAR MAIN BEARING SEAL
CAP
23.5 Rear main oil seal installation details - inline sixcylinder engine
SEALER
23.3 Tap around the outer edge o f the n e w oil seal w i t h a
hammer and a blunt punch t o seat i t squarely i n the bore
lnline six-c ylinder engines
Refer to illustrations 23.5 and 23. 7
4 Inspect the rear main bearing cap and engine block mating surfaces,
as well as the seal grooves, for nicks, burrs and scratches. Remove
any defects with a fine file or deburring tool.
5 lnstall the semi-circular seal section in the block with the lip facing
the front of the engine (see illustration).
6 Repeat the procedure t o install the other seal half in the rear main
bearing cap.
7 During final installation o f the crankshaft (after the main bearing
oil clearances have been checked with Plastigage) as described in Section 22, apply a thin, even coat of anaerobic type gasket sealant t o
the chamfered areas of the cap or block (see illustration). Don't get
any sealant on the bearing face, crankshaft journal, seal ends or seal
23.7 Apply anaerobic sealant t o the areas shown o n the
rear main bearing cap prior t o installation (don't get sealant
i n the grooves or o n the seal)
The Motor Manual Guy
Chapter 2 Part D
General engine overhaul procedures
CRANKSHAFT
OIL PAN
GASKET SURFACE
\
FRONT
Q
ENGINE LEFT
C
ENGINE FRONT
2D-27
ENGINE RIGHT ~
'C
s24.5 Position the piston ring gaps as shown here before
installing the pistonlconnecting rod assemblies in the engine
A Oil ring rail gaps
B Second compression
ring gap
C Notch in piston
A
D Oil ring spacer gap (tang
in hole or slot with arc)
E Top compression ring gap
REAR FACE
OF ENGINE BLOCK
ENGINE
BLOCK
23.9
installing the rear main oil seal - 1 9 8 4 V6 engine
A Tool
B Seal
C Rear of crankshaft
D Alignment arrow
{points do wn)
2D
2 4 Pistonslconnecting rods
installation and
rod bearing oil clearance check
Refer to illustrations 24.5, 24.9, 24. 1 1, 24.13 and 24.17
1 Before installing the pistonlconnecting rod assemblies, the cylinder
walls must be perfectly clean, the top edge of each cylinder must be
chamfered, and the crankshaft must be in place.
2 Remove the cap from the end of the number one connecting rod
(refer to the marks made during removal). Remove the original bearing inserts and wipe the bearing surfaces of the connecting rod and
cap with a clean, lint-free cloth. They must be kept spotlessly clean.
24.9
The arrow must point towards the front of the engine
Connecting rod bearing oil clearance check
3 Clean the back side of the new upper bearing insert, then lay it
in place in the connecting rod. Make sure the tab on the bearing fits
into the recess in the rod. Don't hammer the bearing insert into place
and be very careful not to nick or gouge the bearing face. Don't lubricate
the bearing at this time.
4 Clean the back side of the other bearing insert and install it in the
rod cap. Again, make sure the tab on the bearing fits into the recess
in the cap, and don't apply any lubricant. It's critically important that
the mating surfaces of the bearing and connecting rod are perfectly
clean and oil free when they're assembled.
5 Position the piston ring gaps at intervals around the piston (see
illustration).
6 Slip a section of plastic or rubber hose over each connecting rod
cap bolt.
7 Lubricate the piston and rings with clean engine oil and attach a
piston ring compressor to the piston. Leave the skirt protruding about
114-inch to guide the piston into the cylinder. The rings must be compressed until they're flush with the piston.
8 Rotate the crankshaft until the number one connecting rod journal
is at BDC (bottom dead center) and apply a coat of engine oil to the
cylinder walls.
9 With the arrow or notch on top of the piston (see illustration) facing
the front of the engine, gently insert the pistonlconnecting rod assembly
into the number one cylinder bore and rest the bottom edge of the ring
compressor on the engine block.
10 Tap the top edge of the ring compressor to make sure it's contacting the block around its entire circumference.
1 1 Gently tap on the top of the piston with the end of a wooden hammer handle (see illustration) while guiding the end of the connecting
rod into place on the crankshaft journal. The piston rings may try t o
24.1 1 The piston can be driven (gently) into the cylinder
bore with the end of a wooden hammer handle
pop out of the ring compressor just before entering the cylinder bore,
so keep some downward pressure on the ring compressor. Work
slowly, and if any resistance is felt as the piston enters the cylinder,
stop immediately. Find out what's hanging up and fix it before proceeding. Do not, for any reason, force the piston into the cylinder you might break a ring and/or the piston.
12 Once the pistonlconnecting rod assembly is installed, the connecting rod bearing oil clearance must be checked before the rod cap is
The Motor Manual Guy
2D-28
Chapter 2 Part D
General engine overhaul procedures
24.13 Lay the Plastigage strips on each rod bearing
journal, parallel t o the crankshaft centerline
permanently bolted in place.
1 3 Cut a piece of the appropriate size Plastigage slightly shorter than
the width of the connecting rod bearing and lay it in place on the number
one connecting rod journal, parallel with the journal axis (see illustration).
1 4 Clean the connecting rod cap bearing face, remove the protective
hoses from the connecting rod bolts and install the rod cap. Make sure
the mating mark on the cap is on the same side as the mark on the
connecting rod.
1 5 Install the nuts and tighten them to the specified torque, working
up to it in three steps. Note: Use a thin-wallsocket to avoiderroneous
torque readings that can result if the socket is wedged between the
rod cap and nut. If the socket tends to wedge itself between the nut
and the cap, lift up on i t slighty until it no longer contacts the cap.
Do not rotate the crankshaft at any time during this operation.
16 Remove the nuts and detach the rod cap, being very careful not
to disturb the Plastigage.
17 Compare the width of the crushed Plastigage t o the scale printed
on the Plastigage envelope to obtain the oil clearance (see illustration).
Compare it to the Specifications to make sure the clearance is correct.
18 If the clearance is not as specified, the bearing inserts may be the
wrong size (which means different ones will be required). Before
deciding that different inserts are needed, make sure that no dirt or
oil was between the bearing inserts and the connecting rod or cap when
the clearance was measured. Also, recheck the journal diameter. If the
Plastigage was wider at one end than the other, the journal may be
tapered (refer to Section 18).
Final connecting rod installation
19 Carefully scrape all traces of the Plastigage material off the rod
journal and/or bearing face. Be very careful not to scratch the bearing use your fingernail or the edge of a credit card.
2 0 Make sure the bearing faces are perfectly clean, then apply a
uniform layer of clean moly-base grease or engine assembly lube t o
both of them. You'll have t o push the piston into the cylinder to expose the face of the bearing insert in the cbnnecting rod - be sure
to slip the protective hoses over the rod bolts first.
21 Slide the connecting rod back into place on the journal, remove
the protective hoses from the rod cap bolts, install the rod cap and
tighten the nuts t o the specified torque. Again, work up to the torque
in three steps.
2 2 Repeat the entire procedure for the remaining pistonslconnecting
rods.
23 The important points to remember are . . .
a) Keep the back sides of the bearing inserts and the insides of the
connecting rods and caps perfectly clean when assembling them.
b) Make sure you have the correct pistonlrod assembly for each
cylinder.
c) The notch or mark on the piston must face the front of the engine.
d) Lubricate the cylinder walls with clean oil.
24.1 7 Measuring the width of the crushed Plastigage t o
determine the rod bearing oil clearance (be sure t o use the
correct scale - standard and metric scales are included)
Lubricate the bearing faces when installing the rod caps after the
oil clearance has been checked.
2 4 After all the piston/connecting rod assemblies have been properly
installed, rotate the crankshaft a number of times by hand to check
for any obvious binding.
25 As a final step, the connecting rod end play must be checked. Refer
to Section 12 for this procedure.
26 Compare the measured end play to the Specifications to make sure
it's correct. If it was correct before disassembly and the original
crankshaft and rods were reinstalled, it should still be right. If new rods
or a new crankshaft were installed, the end play may be inadequate.
If so, the rods will have t o be removed and taken to an automotive
machine shop for resizing.
e)
25 Initial start-up and break-in after overhaul
Warning: Have a fire extinguisher handy when starting the engine for
the first time.
1 Once the engine has been installed in the vehicle, double-check
the engine oil and coolant levels.
2 With the spark plugs out of the engine and the ignition system
disabled (see Section 3), crank the engine until oil pressure registers
on the gauge or the light goes out.
3 Install the spark plugs, hook up the plug wires and restore the ignition system functions (Section 3).
4 Start the engine. It may take a few moments for the fuel system
to build up pressure, but the engine should start without a great deal
of effort. Note: If backfiring occurs through the carburetor or throttle
body, recheck the valve timing and ignition timing.
5 After the engine starts, it should be allowed to warm up to normal
operating temperature. While the engine is warming up, make a thorough check for fuel, oil and coolant leaks.
6 Shut the engine off and recheck the engine oil and coolant levels.
7 Drive the vehicle to an area with minimum traffic, accelerate at
full throttle from 3 0 to 50 mph, then allow the vehicle to slow to 3 0
mph with the throttle closed. Repeat the procedure 1 0 or 12 times.
This will load the piston rings and cause them t o seat properly against
the cylinder walls. Check again for oil and coolant leaks.
8 Drive the vehicle gently for the first 500 miles (no sustained high
speeds) and keep a constant check on the oil level. It is not unusual
for an engine to use oil during the break-in period.
9 A t approximately 500 to 6 0 0 miles, change the oil and filter.
1 0 For the next few hundred miles, drive the vehicle normally. Do not
pamper it or abuse it.
1 After 2000 miles, change the oil and filter again and consider the
engine broken in.
The Motor Manual Guy
Chapter 3 Cooling.
heating and air conditioning systems
Contents
Air conditioner and heater control assembly.removal
and installation
16
Air conditioning system compressor.removal
and installation
14
Air conditioning system condenser.removal
and installation
15
Air conditioning system
check and maintenance
12
Air conditioning system receiver-drier.removal
and installation
13
Antifreeze
general information
2
Coolant level check
See Chapter 1
Coolant reservoir
removal and installation
7
Coolant temperature sending unit.check
and replacement
6
Cooling system check
See Chapter 1
Cooling system servicing (draining. flushing
and refilling)
Drivebelt - check. adjustment and
replacement
Engine cooling fan and clutch - check
and replacement
General information
Heater and air conditioner blower
motor - removal and installation
Heater core - replacement
Radiator - removal and installation
Thermostat
check and replacement
Underhood hose check and replacement
Water pump - check
Water pump - replacement
Specifications
General
Coolant capacity
Drivebelt tension
Radiator pressure cap rating
Four-cylinder and V6 engines
lnline six-cylinder engines
Thermostat opening temperature
See Chapter 1
See Chapter 1
Torque specifications
Ft-lbs
12 t o 1 5 psi
16 to 18 psi
195° F
Four-cylinder engine
15 to 22
13
13
Fan and pulley-to-water pump hub bolts
Thermostat housing bolts
Water pump attaching bolts
V6 engine
Fan and pulley-to-water pump hub bolts
Thermostat housing attaching bolts
Water pump attaching bolts
6mm
8mm
10mm
lnline six-cylinder engine
Fan and pulley-to-hub bolts
Thermostat housing bolts
Water pump attaching bolts
:...
15 to 22
2 0 to 3 0
6 to 9
1 3 t o 18
20 to 30
18
13
9 to 1 8
See Chapter 1
.See Chapter 1
5
1
10
11
4
3
See Chapter 1
8
9
3
The Motor Manual Guy
3-2
1
Chapter 3
Cooling, heating and air conditioning systems
General information
Engine cooling system
All vehicles covered by this manual employ a pressurized engine cooling system with thermostatically controlled coolant circulation. An impeller type water pump mounted on the front of the block pumps
coolant through the engine. The coolant flows around each cylinder
and toward the rear of the engine. Cast-in coolant passages direct
coolant around the intake and exhaust ports, near the spark plug areas
and in close proximity to the exhaust valve guides.
A wax pellet type thermostat is located in a housing near the front
of the engine. During warm up, the closed thermostat prevents coolant
from circulating through the radiator. As the engine nears normal
operating temperature, the thermostat opens and allows hot coolant
to travel through the radiator, where it's cooled before returning to
the engine.
The cooling system is sealed by a pressure type cap on the radiator
or coolant reservoir, which raises the boiling point of the coolant and
increases the cooling efficiency of the radiator. If the system pressure
exceeds the cap pressure relief value, the excess pressure in the system
forces the spring-loaded valve inside the cap off its seat. This allows
either excess pressure to escape to the atmosphere (reservoir-mounted
caps on inline six-cylinder vehicles) or coolant to escape through an
overflow tube into a coolant reservoir (radiator-mounted caps on fourcylinder and V 6 vehicles). When the system cools on four-cylinder and
V6 vehicles, the excess coolant is automatically drawn from the reservoir back into the radiator.
On four-cylinder and V 6 vehicles, the coolant reservoir does double
duty as both the point at which fresh coolant is added to the cooling
system t o maintain the proper fluid level and as a holding tank for
overheated coolant. On inline six-cylinder vehicles, the coolant reservoir
is a pressurized part of the cooling system through which coolant flows
in normal operation.
Heating system
The heating system consists of a blower fan and heater core located
in the heater box, the hoses connecting the heater core to the engine
cooling system and the heaterlair conditioning control head on the
dashboard. Hot engine coolant is circulated through the heater core.
When the heater mode is activated, a flap door opens t o expose the
heater box to the passenger compartment. A fan switch on the control
head activates the blower motor, which forces air through the core,
heating the air.
Air conditioning system
The air conditioning system consists of a condenser mounted in front
of the radiator, an evaporator mounted adjacent t o the heater core,
a compressor mounted on the engine, a receiver-drier which contains
a high pressure relief valve and the plumbing connecting all of the above
components.
A blower fan forces the warmer air of the passenger compartment
through the evaporator core (sort of a radiator-in-reverse), transferring
the heat from the air to the refrigerant. The liquid refrigerant boils off
into low pressure vapor, taking the heat with it when it leaves the
evaporator.
2
and scale in the system. Use distilled water with the antifreeze.
Before adding antifreeze, check all hose connections, because antifreeze tends to search out and leak through very minute openings.
Engines don't normally consume coolant, so if the level goes down,
find the cause and correct it.
The exact mixture of antifreeze-to-water which you should use
depends on the relative weather conditions. The mixture should contain
at least 50 percent antifreeze, but should never contain more than 70
percent antifreeze. Consult the mixture ratio chart on the antifreeze
container before adding coolant. Hydrometers are available at most
auto parts stores to test the coolant. Use antifreeze which meets the
vehicle manufacturer's specifications.
3 Thermostat - check and replacement
Warning: Do not remove the radiator cap, drain the coolant orreplace
the thermostat until the engine has cooled completely.
Check
1 Before assuming the thermostat is to blame for a cooling system
problem, check the coolant level, drivebelt tension (Chapter 1) and
temperature gauge (or light) operation.
2 If the engine seems to be taking a long time to warm up (based
on heater output or temperature gauge operation), the thermostat is
probably stuck open. Replace the thermostat with a new one.
3 If the engine runs hot, use your hand to check the temperature
of the upper radiator hose. If the hose isn't hot, but the engine is, the
thermostat is probably stuck closed, preventing the coolant inside the
engine from escaping to the radiator. Replace the thermostat. Caution:
Don't drive the vehicle without a thermostat. The computer may sta y
in open loop and emissions and fuel economy will suffer.
4 If the upper radiator hose is hot, it means that the coolant is flowing
and the thermostat is open. Consult the Troubleshooting Section at
the front of this manual for cooling system diagnosis.
Replacement
Refer to illustrations 3.8, 3. 10 and 3.14
5 Disconnect the negative battery cable from the battery.
6 Drain the cooling system (see Chapter 1 ). If the coolant is relatively
new or in good condition (see Chapter 1 ), save it and reuse it.
7 Follow the upper radiator hose to the engine to locate the thermostat housing.
8 Loosen the hose clamp(s), then detach the hose(s) from the fitt i n g ( ~(see
)
illustration). If a hose is stuck, grasp it near the end with
a pair of Channelock pliers and twist it to break the seal, then pull it
off. If a hose is old or deteriorated, cut it off and install a new one.
9 If the outer surface of the large fitting that mates with the hose
is deteriorated (corroded, pitted, etc.) it may be damaged further by
hose removal. If it is, the thermostat housing cover will have t o be
replaced.
Antifreeze - general information
Warning: Do not allow antifreeze to come in contact with you; skin
or painted surfaces of the vehicle. Rinse off spills immediately with
plenty of water. Antifreeze, if consumed, can be fatal to children and
pets, so wipe up garage floor and drip pan coolant spills immediately.
Keep antifreeze containers covered and repair leaks in your cooling
system as soon as they are noticed.
The cooling system should be filled with a water/ethylene glycol
based antifreeze solution, which will prevent freezing down t o at least
-20°F, or lower if local climate requires it. It also provides protection
against corrosion and increases the coolant boiling point.
The cooling system should be drained, flushed and refilled at the
specified intervals (see Chapter 1 ). Old or contaminated antifreeze solutions are likely to cause damage and encourage the formation of rust
3.8
Four-cylinder models (shown) and inline six-cylinder engines
have t w o hoses connected t o the thermostat housing
The Motor Manual Guy
Chapter 3
Cooling, heating and air conditioning systems
3.14 Before installing the gasket, apply a thin, uniform
layer of RTV sealant to both sides of it - inline six-cylinder
engine shown; others similar
3.10 After the
are removed, remove the bolts
(arrows) and detach the housing from the engine six-cylinder engine shown; others similar
10 Remove the bolts and detach the housing cover (see illustration).
If the cover is stuck, tap it with a soft-face hammer to jar it loose. Be
prepared for some coolant t o spill as the gasket seal is broken.
1 1 Note how it's installed (which end is facing out), then remove the
thermostat.
12 Stuff a rag into the engine opening, then remove all traces of old
gasket material and sealant from the housing and cover with a gasket
scraper. Remove the rag from the opening and clean the gasket mating
surfaces with lacquer thinner or acetone.
1 3 Install the new thermostat in the housing. Make sure the correct
end faces out - the spring end is normally directed into the engine.
1 4 Apply a thin, uniform layer of RTV sealant to both sides of the new
gasket (see illustration) and position it on the housing.
15 Install the cover and bolts. Tighten the bolts to the specified torque.
1 6 Reattach the hose(s) to the fitting(s) and tighten the hose clamp(s)
securely.
17 Refill the cooling system (see Chapter 1 ).
18 Start the engine and allow it to reach normal operating temperature,
then check for leaks and proper thermostat operation (as described
in Steps 2 through 4).
4.5
4
Radiator
- removal and installation
Refer to illustrations 4.5, 4.8a, 4.Bb and 4.9
Warning: Wait until the engine is completely cool before beginning this
procedure.
1 Disconnect the negative battery cable from the battery.
2 Drain the cooling system (see Chapter 1 ). If the coolant is relatively
new or in good condition, save it and reuse it.
3 Loosen the hose clamps, then detach the radiator hoses from the
fittings on the radiator. If they're stuck, grasp each hose near the end
with a pair of Channelock pliers and twist it to break the seal, then
be careful not to distort the radiator fittings! If the hoses
pull it off
are old or deteriorated, cut them off and install new ones.
4 On four-cylinder and V6 models, disconnect the reservoir hose from
the radiator filler neck.
5 On four-cylinder and V 6 models, remove the screws that attach
the radiator fan shroud to the radiator (see illustration) and slide the
shroud toward the engine. On
six-cylinder models equipped with
auxiliary electric cooling fans, remove the electric fan (see Section
3
l
Radiator and related components - exploded view
(four-cylinder and V6 engines)
I Drain
2 Radiator hoses
3 Radiator fan shroud
3-3
4 A/C condenser
5 £-clip ring
6 Coolant reservoir
4
5
The Motor Manual Guy
3-4
Chapter 3
Cooling, heating and air conditioning systems
On
six-cylinder models, use a Torx-bit t o remove the
hood safety catch, then unbolt the panel above the radiator
On all inline six-cylinder models, remove the mounting bolts for the
mechanical fan shroud, lift the shroud up until it clears the slots in the
bottom bracket of the radiator, then push the shroud over the fan.
6 If the vehicle is equipped with an automatic transmission, disconnect the cooler lines from the rear of the radiator. Use a drip pan to
catch spilled fluid.
7 Plug the lines and fittings
8 Remove the radiator mounting bolts (see illustrations).
9 Carefully lift out the radiator (see illustration). Don't spill coolant
on the vehicle or scratch the paint.
10 With the radiator removed, it can be inspected for leaks and
damage. If it needs repair, have a radiator shop or dealer service department perform the work as special techniques are required.
11 Bugs and dirt can be removed from the front of the radiator with
compressed air and a soft brush. Don't bend the cooling fins as this
is done.
12 Check the radiator mounts for deterioration and make sure there's
nothing in them when the radiator is installed.
13 Installation is the reverse of the removal procedure.
1 4 After installation, fill the cooling system with the proper mixture
of antifreeze and water. Refer to Chapter 1 if necessary.
1 5 Start the engine and check for leaks. Allow the engine to reach
normal operating temperature, indicated by the upper radiator hose
becoming hot. Recheck the coolant level and add more if required.
16 If you're working on an automatic transmission equipped vehicle,
check and add fluid as needed.
On some models, you must remove the bolt (arrow)
t o disconnect the air conditioning line bracket attached t o
the top of the radiator
5
Engine cooling fan and clutch - check and replacement
Warning: To avoid possible injury or damage, DO NOT operate the
engine with a damaged fan. Do not attempt to repair fan blades replace a damaged fan with a new one.
Removal and installation
Electric fan (some inline six-cylinder models)
Refer to illustration 5.2
1
Disconnect the negative battery cable from the battery.
2 Disconnect the electric cooling fan wire harness connector (see
illustration).
3 Remove the mounting bolts (see illustration 5.2), then carefully
lift the fan out of the engine compartment.
4 T o detach the fan from the motor, remove the motor shaft clip.
5 To remove the bracket from the fan motor, remove the mounting
nuts.
6 Installation is the reverse of removal.
Mechanical fan with viscous clutch
Refer to illustration 5.8
7 Disconnect the negative battery cable. Remove the fan shroud
COOLING FAN
CONNECTOR
4.9 When lifting the radiator out, be careful not t o
damage the cooling fins with the fan and fan shroud
(arrows) - inline six-cylinder model shown
5.2 On inline six-cylinder engines equipped with electric
cooling fans, disconnect the electrical connector, remove
the mounting bolt, and lift the fan out
The Motor Manual Guy
Chapter 3
Cooling, heating and air conditioning systems
5.13 Disconnect the fan electrical connector and run
jumper wires directly to the positive and negative terminals
of the battery
be sure the clips don't touch each other
and create a short circuit
5.8 The fan clutch is mounted with four nuts; two are
visible in thi$ photo (arrows)
mounting screws, lift the shroud up until it clears the slots in the bottom
bracket of the radiator, then push the shroud over the fan.
8 Remove the nuts attaching the fan/clutch assembly to the water
pump hub or, on inline six-cylinder models, to the fan bearing hub (see
illustration).
9 Lift the fan/clutch assembly (and shroud, if necessary) out of the
engine compartment.
10 Carefully inspect the fan blades for damage and defects. Replace
it if necessary.
11 At this point, the fan may be unbolted from the clutch, if necessary.
If the fan clutch is stored, position it with the radiator side facing down.
1 2 Installation is the reverse of removal. Be sure to tighten the fan
and clutch mounting nuts evenly and securely.
Check
Electric fan
Refer to illustration 5. 13
1 3 To test the motor, unplug the electrical connector at the motor
and use jumper wires to connect the fan directly t o the battery (see
illustration). If the fan still doesn't work, replace the fan motor.
1 4 If the motor tested OK, the fault lies in the coolant temperature
switch or the wiring which connects the components. Carefully check
all wiring and connections. If no obvious problems are found, further
diagnosis should be done by a dealer service department or repair shop.
6.1a The coolant temperature sending
unit on four-cylinder engines is located
near the left rear corner of the cylinder
head (arrow)
3-5
Mechanical fan with viscous clutch
15 Disconnect the negative battery cable and rock the fan back and
forth by hand t o check for excessive bearing play.
16 With the engine cold, turn the fan blades by hand. The fan should
turn freely.
1 7 Visually inspect for substantial fluid leakage from the clutch assembly. If problems are noted, replace the clutch assembly.
18 With the engine completely warmed up, turn off the ignition switch
and disconnect the negative battery cable from the battery. Turn the
fan by hand. Some drag should be evident. If the fan turns easily,
replace the fan clutch.
6
Coolant temperature sending unit - check and replacement
Refer to illustrations 6. la, 6.1b and 6. I c
Warning: Wait until the engine i s completely cool before beginning this
procedure.
1 The coolant temperature indicator system is composed of a light
or temperature gauge mounted in the instrument panel and a coolant
temperature sending unit mounted on the engine (see illustrations).
Some vehicles have more than one sending unit, but only one is used
6. b The coolant temperature sending
unit on V6 engines (arrow) is located
near the left front corner of the
intake manifold
6. l c The coolant temperature sending
unit on inline six-cylinder engines is
located near the left rear corner of the
cylinder head (arrow)
The Motor Manual Guy
3-6
Chapter 3
Cooling, heating and air conditioning systems
for the indicator system. Warning: If the vehicle is equipped with an
electric cooling fan, stay clear of the fan blades. The fan can come
on at any time.
2 If an overheating indication occurs, check the coolant level in the
system and then make sure the wiring between the light or gauge and
the sending unit is secure and all fuses are intact.
3 When the ignition switch is turned on and the starter motor is turning, the indicator light should be on (overheated engine indication).
4 If the light is not on, the bulb may be burned out, the ignition switch
may be faulty or the circuit may be open. Test the circuit by grounding
the wire to the sending unit while the ignition is on (engine not running
for safety). If the gauge deflects full scale or the light comes on, replace
the sending unit.
5 As soon as the engine starts, the light should go out and remain
out unless the engine overheats. Failure of the light to go out may be
due to a grounded wire between the light and the sending unit, a defective sending unit or a faulty ignition switch. Check the coolant t o make
sure it's the proper type. Plain water may have too low a boiling point
to activate the sending unit.
6 If the sending unit must be replaced, simply unscrew it from the
engine and install the replacement. Use sealant on the threads. Make
sure the engine is cool before removing the defective sending unit.
There will be some coolant loss as the unit is removed, so be prepared
to catch it. Check the level after the replacement has been installed.
7.3a On four-cylinder and V6 models, the coolant
reservoir is fastened by t w o screws (arrows)
8.4 The water pump weep hole (arrow) will drip coolant
when the seal on the pump shaft fails (pump removed
from engine for clarity)
7
Coolant reservoir - removal and installation
Refer to illustrations 7.3a and 7.3b
Warning: Wait until the engine is completely cool before beginning this
procedure.
1 Remove the reservoir filler cap and drain the cooling system (see
Chapter 1) until the coolant level is below the bottom of the reservoir.
2 Loosen the hose clamps and detach the hose(s) from the reservoir.
3 Remove the screws or retaining strap and lift the reservoir from
the vehicle (see illustrations).
4 Installation is the reverse of removal.
5 Refill the cooling system and check for leaks.
8 Water pump - check
Refer to illustrations 8.4 and 8.5
1 A failure in the water pump can cause serious engine damage due
to overheating.
2 There are three ways to check the operation of the water pump
while it's installed on the engine. If the pump is defective, it should
be replaced with a new or rebuilt unit.
7.3b
On inline six-cylinder models, the coolant reservoir is
fastened by a rubber retaining strap (arrow)
8.5 Grasp the water pump flange and try t o rock the
shaft back and forth t o check for play (fan and pulley
shown removed for clarity)
The Motor Manual Guy
Chapter 3
Cooling, heating and air conditioning systems
3-7
3
With the engine running at normal operating temperature, squeeze
the upper radiator hose. If the water pump is working properly, a
pressure surge should be felt as the hose is released. Warning: Keep
your hands away from the fan blades!
4 Water pumps are equipped with weep or vent holes. If a failure
occurs in the pump seal, coolant will leak from the hole. In most cases
you'll need a flashlight to find the hole on the water pump from underneath to check for leaks (see illustration).
5 If the water pump shaft bearings fail there may be a howling sound
at the front of the engine while it's running. Shaft wear can be felt
if the water pump pulley is rocked up and down (see illustration). Don't
mistake drivebelt slippage, which causes a squealing sound, for water
pump bearing failure.
9
Water pump - replacement
Refer to illustrations 9.4, 9. 7a, 9. 7b and 9.7c
Warning: Wait until the engine is completely cool before beginning this
procedure.
1 Disconnect the negative battery cable from the battery.
2 Drain the cooling system (see Chapter 1 ). If the coolant is relatively
new or in good condition, save it and reuse it.
3 Remove the cooling fan and shroud (see Section 5).
4 On inline six-cylinder engines, loosen the pulley-to-water pump
bolts (see illustration). Remove the drivebelts (see Chapter 1) and the
pulley at the end of the water pump shaft.
5 Loosen the clamps and detach the hoses from the water pump.
If they're stuck, grasp each hose near the end with a pair of Channelock
pliers and twist it to break the seal, then pull it off. If the hoses are
deteriorated, cut them off and install new ones.
6 Remove all accessory brackets from the water pump. When removing the power steering pump and air conditioning compressor, don't
disconnect the hoses. Tie the units aside with the hoses attached. Keep
the power steering pump upright so fluid doesn't spill.
7 Remove the bolts and detach the water pump from the engine.
Note the locations of the various lengths and different types of bolts
as they're removed to ensure correct installation (see illustrations).
8 Clean the bolt threads and the threaded holes in the engine to
remove corrosion and sealant.
9 Compare the new pump to the old one to make sure they're
identical.
10 Remove all traces of old gasket material from the engine with a
gasket scraper.
1 1 Clean the engine and new water pump mating surfaces with lacquer
thinner or acetone.
12 Apply a thin coat of RTV sealant to the engine side of the new
gasket.
13 Apply a thin layer of RTV sealant to the gasket mating surface of
the new pump, then carefully mate the gasket and the pump. Slip a
9.7b
V6 engine water pump
Water pump
9.4
On
six-cylinder engines, loosen the
water pump bolts before removing the drivebelt
9.7a
Four-cylinder engine water pump and gasket
- exploded view
2 Timing chain cover
9.7c
Water pump bolt locations for the
six-cylinder engine
The Motor Manual Guy
Chapter 3
3-8
Cooling, heating and air conditioning systems
couple of bolts through the pump mounting holes to hold the gasket
in place.
1 4 Carefully attach the pump and gasket to the engine and thread
the bolts into the holes finger tight.
15 Install the remaining bolts (if they also hold an accessory bracket
in place, be sure t o reposition the bracket at this time). Tighten them
to the specified torque in 114-turn increments. Note that the three sizes
of bolts on V6 engines require different torques. Don't overtighten them
or the pump may be distorted.
1 6 Reinstall all parts removed for access t o the pump.
1 7 Refill the cooling system and check the drivebelt tension (Chapter 1 ). Run the engine and check for leaks.
10 Heater and air conditioner blower
motor
removal and installation
Refer to illustrations 10.2 and 10.5
Removal
Disconnect the negative cable from the battery.
Disconnect the blower motor wires (see illustration).
3 Remove the blower motor mounting screws (see illustration 10.2).
4 Lift the blower motor from the vehicle. If you are not replacing
the motor, you may disregard steps 5 through 7.
5 Detach the fan retainer clip from the fan hub (see illustration).
6 Slip the fan off the old motor shaft, remove the motor-to-cover
attaching nuts and pull the motor off the cover.
7 Mount the new motor on the cover and slip the fan onto the shaft.
Install the retainer clip (see illustration 10.5).
1
2
Installation
8 Place the blower motor in position and install the mounting screws.
9 Reconnect the wires and battery cable. Test the motor in operation.
11
Heater core
- replacement
Warning: The air conditioning system is under high pressure. DO NOT
disconnect any refrigerant fittings until after the system has been
discharged by a dealer service department or service station.
Refer to illustrations 1 1.6, 1 1. 7, 1 1.8, 1 1. 1 1, 11. 15, 1 1. 17a
and 11. 17b
Removal
10.2 The blower motor is mounted on the engine-side of
the firewall - disconnect the electrical connector (1 ), then
remove the three blower motor mounting screws (2) - the
top screw is hidden in this photo
(0. 710-inch)
BLOWER FAN
'
1 On air conditioned models, have the system discharged (see the
Warning above).
2 Disconnect the negative cable from the battery.
3 Drain the cooling system (see Chapter 1 and disconnect the heater
hoses at the heater core inlet and outlet.
4 Disconnect the blower motor electrical connector (see Section 10).
5 Remove the console (if equipped) and the lower instrument panel
(see Chapter 1 1 ).
6 On air conditioned models, disconnect the A/C hoses from the expansion valve (see illustration).
7 Label and disconnect the electrical wires at the air conditioning
relay, the air conditioning thermostat (if equipped) and the blower motor
resistors. Disconnect the vacuum hose at the vacuum motor (see
illustration).
OUTLET TUBES
EXPAN SION
VALVE
3
4
10.5 Pry the clip ears (1 and 3)
off the flat surface (2) of the
motor shaft (4) - bend the
retaining clip like the original
when installing it
11.6
Disconnect the A/C hoses from the expansion valve
The Motor Manual Guy
Chapter 3 Cooling, heating and air conditioning systems
Cut the retaining strap that holds the blower/evaporator housing
to the heater core housing (see illustration).
9 Disconnect the heater control cable (see illustration 11.8).
10 Detach the clip at the rear of the blower housing flange and remove
the
.
. retainina screws (see illustration 11.8).
1 1 Remove the housing attaching nuts from the studs on the engine
compartment side of the firewall (see illustration).
12 Remove the evaporator drain tube.
13 Remove the right kick panel and then the instrument panel support
bolt.
8
3-9
14 Gently pull out on the right side of the dash and rotate the housing
down and toward the rear of the vehicle to disengage the housing studs
from the dash panel. Then remove the blower/evaporator housing.
1 5 Remove the retaining screws (see illustration) and remove the
heater core by pulling it straight down out of the housing.
/nstal!ation
16 Position the heater core in the housing and install the screws. Be
sure to cement the seal in place to keep it from moving when the blower
assembly is installed (see illustration 11.15).
3
11.7
Blower housing components - with air conditioning
Air conditioning relay
2 Blower motor resistors
3 Air conditioning thermostat
4 Vacuum motor
11.8 Cut the retaining strap (5) and remove the heater
control cable (6), the rear blower housing flange clip (7)
and the retaining screws (8)
RETAINING
SCREWS
1 1 .1 1
;;
Remove the housing attaching nuts
1 1.15 Remove the heater core retaining screws - when
installing it, cement the seal in place to keep it from
moving when the blower assembly is installed
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___.:J
The Motor Manual Guy
3-10
Chapter 3
Cooling, heating and air conditioning systems
~~
~
\\
ALIGNMENT
TAB
ALIGNMENT
TABS\'.
~
/
1 1.17a
Use the alignment tabs to position the housing and
...
17 Reinstall the remaining parts in the reverse order of removal. Be
sure to use the alignment tabs (see illustrations) to position the housings. Note: When installing the blower/evaporator housing, avoid trapping wires between the housing fresh air inlet and the dash panel on
the right side of the housing.
18 Refill the cooling system.
19 Have the air conditioning system (if equipped) evacuated, recharged
and leak tested.
20 Start the engine and check for proper operation.
12
Air conditioning system - check and maintenance
Refer to illustrations 12.1a and 12. 7b
Warning: The air conditioning system is under high pressure. Do not
loosen any hose fittings or remove any components until after the system has been discharged by a dealer service department or service
station. Always wear eye protection when disconnecting air conditioning system fittings.
1 The following maintenance checks should be performed on a regular basis to ensure the air conditioner continues to operate at peak
efficiency.
a) Check the compressor drivebelt. If it's worn or deteriorated, replace it (see Chapter 1).
b) Check the drivebelt tension and, if necessary, adjust it (see Chapter 1).
c) Check the system hoses. Look for cracks, bubbles, hard spots
and deterioration. Inspect the hoses and all fittings for oil bubbles
and seepage. If there's any evidence of wear, damage or leaks,
replace the hose(s).
d) lnspect the condenser fins for leaves, bugs and other debris. Use
12.7a
On four-cylinder and V6 models, the sight glass is
adjacent to the radiator cap (arrow)
11.17b
...
don't miss this alignment tab
a "fin comb" or compressed air to clean the condenser.
e) Make sure the system has the correct refrigerant charge.
9 Check the evaporator housing drain tube for blockage.
2 It's a good idea to operate the system for about 10 minutes at
least once a month, particularly during the winter. Long term non-use
can cause hardening, and subsequent failure, of the seals.
3 Because of the complexity of the air conditioning system and the
special equipment necessary to service it, in-depth troubleshooting
and repairs are not included in this manual (refer to the Haynes Automotive Heating and Air Conditioning Repair Manual). However, simple
checks and component replacement procedures are provided in this
Chapter.
4 The most common cause of poor cooling is simply a low system
refrigerant charge. If a noticeable drop in cool air output occurs, the
following quick check will help you determine if the refrigerant level is
low.
5 Warm the engine up to normal operating temperature.
6 Place the air conditioning temperature selector at the coldest setting and put the blower at the highest setting. Open the doors (to
make sure the air conditioning system doesn't cycle off as soon as it
cools the passenger compartment).
7 With the compressor engaged - the clutch will make an audible
click and the center of the clutch will rotate - inspect the sight glass
(see illustrations). If the refrigerant looks foamy, it's low. Have the
system charged by a dealer service department or automotive air conditioning shop.
8 If there's no sight glass, feel the inlet and outlet pipes at the compressor. One side should be cold and one hot. If there's no perceptible
difference between the two pipes, there's something wrong with the
compressor or the system. It might be a low charge - it might be
something else. Take the vehicle to a dealer service department or an
automotive air conditioning shop.
, 2. 7b
On inline six-cylinder models, the sight glass is
below the air conditioning compressor
The Motor Manual Guy
Chapter 3
13
Cooling, heating and air conditioning systems
Air conditioning system receiver-drier - removal
and installation
Refer to illustration 13.3
Warning: The air conditioning system is under high pressure. DO NOT
disassemble any part of the system (hose, compressor, line fittings,
etc.) until after the system has been depressurized b y a dealer service
department or service station.
1 Have the air conditioning system discharged (see Warning above).
2 Disconnect the negative battery cable from the battery.
3 Unplug the electrical connector from the pressure switch near the
top of the receiver-drier (see illustration). Note: On four-cylinder and
V6 models, the receiver-drier is mounted adjacent to the radiator. On
inline six-cylinder models, it's below the air conditioning compressor.
4 Disconnect the refrigerant line from the receiver-drier. Use a backup wrench to prevent twisting the tubing.
5 Plug the open fittings to prevent entry of dirt and moisture.
6 Loosen the mounting bracket bolts and lift the receiver-drier out.
7 If a new receiver-drier is being installed, remove the Schrader valve
and pour the oil out into a measuring cup, noting the amount. Add fresh
refrigerant oil to the new receiver-drier equal to the amount removed
from the old unit, plus one ounce.
8 Installation is the reverse of removal.
9 Take the vehicle back to the shop that discharged it. Have the AIC
system evacuated, charged and leak tested.
14
3-1 1
Air conditioning system compressor
and installation
- removal
Refer to illustration 14.3
Warning: The air conditioning system is under high pressure. DO NOT
disassemble any part of the system (hoses, compressor, line fittings,
etc.} until after the system has been depressurized b y a dealer service
department or service station.
Note: The receiver-drier (see Section 13) should be replaced whenever
the compressor is replaced.
1 Have the A/C system discharged (see Warning above).
2 Disconnect the negative battery cable from the battery.
3 Disconnect the compressor clutch electrical connector (see illustration).
4 Remove the drivebelt (see Chapter 1 ).
5 Disconnect the refrigerant lines from the top rear of the compressor.
Plug the open fittings to prevent entry of dirt and moisture.
6 Unbolt the compressor from the mounting brackets and lift it out
of the vehicle.
7 If a new compressor is being installed, follow the directions with
the compressor regarding the draining of excess oil prior to installation.
14.3 Disconnect the compressor clutch
electrical connector (arrow) - inline
six-cylinder engine shown
13.3 Unplug the electrical connector {1) and unbolt the
mounting bracket (2) - inline six-cylinder engine
shown (others similar)
8
The clutch may have to be transferred from the original to the new
compressor.
9 lnstallation is the reverse of removal. Replace all O-rings with new
ones specifically made for AIC system use and lubricate them with
refrigerant oil.
10 Have the system evacuated, recharged and leak tested by the shop
that discharged it.
15
Air conditioning system condenser - removal
and installation
Refer to illustrations 15.5a, 15.5b, 15.5c and 15.6
Warning: The air conditioning system is under high pressure. DO NOT
disassemble any part of the system (hoses, compressor, line fittings,
etc.} until after the system has been depressurized b y a dealer service
department or service station.
Note: The receiver-drier (Section 13) should be replaced whenever the
condenser is replaced.
1 Have the air conditioning system discharged (see Warning above).
2 Disconnect the negatiave battery cable from the battery.
3 Remove the radiator grille (Chapter 1 1 ).
4 Remove the radiator (see Section 4).
5 Disconnect the refrigerant lines from the condenser (see illustrations).
15.5a Disconnect the refrigerant lines
from the condensor (inline six-cylinder
model shown) - be sure t o use a backup wrench t o avoid bending the line
15.5b On inline six-cylinder models.
the lower fitting can be reached
through the grille opening
3
The Motor Manual Guy
Chapter 3
3-12
Cooling, heating and air conditioning systems
15.5c On four-cylinder and V6 models, the refrigerant line
connections are located next to the battery
15.6 On four-cylinder and V6 models, remove the screws
(arrows) and pull off the cover to reach the mounting bolts
6
Remove the mounting bolts from the condenser brackets (see illustration).
7 Lift the condenser out of the vehicle and plug the lines to keep
dirt and moisture out.
8 If the original condenser will be reinstalled, store it with the line
fittings on top t o prevent oil from draining out.
9 If a new condenser is being installed, pour one ounce of refrigerant
oil into it prior to installation.
10 Reinstall the components in the reverse order of removal. Be sure
the rubber pads are in place under the condenser.
1 1 Have the system evacuated, recharged and leak tested by the shop
that discharged it.
16
16.4
Remove the four air conditioning control panel
mounting screws (arrows)
16.5
Unplug the electrical connectors
Air conditioner and heater control assembly - removal
and installation
Refer to illustrations 16.4, 16.5, 16.6, 16.7 and 16.8
1 Disconnect the negative cable from the battery.
16.6
Bend back the locking tab to release the
vacuum connector
The Motor Manual Guy
Chapter 3
Cooling, heating and air conditioning systems
3-13
I~
16.7 Release the control cable locking tab with a screwdriver
Detach the instrument panel bezel (see Chapter 11 ).
Remove the radio (see Chapter 12).
4 Remove the four mounting screws from the air conditioning/heater
control panel (see illustration).
5 Unplug the electrical connectors (see illustration).
6 Detach the vacuum connector by bending back the locking tab (see
2
3
16.8 Detach the ring on the end of the control cable
illustration).
7 Release the control cable locking tab with a screwdriver (see illustration).
8 Detach the ring on the end of the control cable from the arm on
the bottom of the control panel (see illustration).
9 To install the control, reverse the removal procedure.
The Motor Manual Guy
Chapter 4
Fuel and exhaust systems
Contents
Air cleaner - removal and installation.
Air and PCV filter replacement
Carburetor - adjustments
Carburetor choke check
Carburetor - diagnosis and overhaul
Carburetor - removal and installation
Carburetor/throttle body mounting nut
torque check
Drivebelt check, adjustment and replacement . . .
Exhaust system check.
Exhaust system servicing
general information
Fuel filter replacement
general information
Fuel injection system
Fuel lines and fittings - inspection and replacement
Fuel pressure relief (fuel-injected vehicles)
7
See Chapter 1
8
See Chapter 1
10
9
See Chapter 1
See Chapter 1
See Chapter 1
16
See Chapter 1
11
12
2
3
Fuel pumplfuel pressure - check
Fuel pump - removal and installation
4
Fuel system check.
See Chapter 1
6
Fuel tank cleaning and repair - general information
5
Fuel tank - removal and installation.
General information
1
Idle speed check and adjustment
See Chapter 1
Multi-Point fuel Injection (MP!) - component replacement . . . 15
Thermostatically controlled air cleaner check . . .
See Chapter 1
Throttle body (TBl-equipped vehicles)
removal
and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Throttle Body lnjection (TB!)
system
component replacement
14
Throttle linkage inspection
See Chapter 1
Specifications
Torque specifications
Fuel pump (mechanical) mounting bolts.
Carburetor-to-intake manifold mounting nuts
Throttle body mounting nuts (vehicles equipped with TB!)
1
...
General information
Fuel system
The fuel system consists of the fuel tank, the fuel pump, the fuel
filter, a thermostatically controlled air cleaner assembly and a carburetor
or fuel injection system.
1984 and 1985 models with a four-cylinder engine are equipped with
a one-barrel Carter YFA feedback carburetor. Vehicles with this engine
manufactured from 1986 on are equipped with a Throttle Body lnjection
(TB!) system.
Vehicles with a V6 engine are equipped with either a 2SE (49-state
and Canada) or E2SE (California) two-barrel feedback carburetor.
Vehicles with an inline six-cylinder engine are equipped with a MultiPoint lnjection (MP!) system.
The fuel pumps of carbureted and fuel-injected vehicles are different:
Ft-lbs
13 to 1 9
13 to 19
16
Carbureted vehicles use a mechanical pump driven by an eccentric lobe
on the camshaft. Fuel injected engines use a gear/rotor type pump
driven by an electric motor. The mechanical pump is mounted on the
engine block; electric pumps are installed inside the fuel tank. Finally,
it should be noted that the electric pumps used with TBI and MPI
systems are different and cannot be interchanged.
Two different fuel feedback systems are used: One for four-cylinder
engines and one for V6 engines sold in California. For more information
on the fuel feedback systems, refer to Chapter 6.
Exhaust system
The basic exhaust system on all vehicles consists of a single or dual
exhaust manifold, a front exhaust pipe, a catalytic converter, heat
shield(s), and a muffler and tailpipe. The exhaust system is suspended
from the underside of the vehicle and insulated from vibration by a
series of rubber hangers.
The Motor Manual Guy
Chapter 4
Fuel and exhaust systems
2.5 To relieve the fuel pressure on an MPI-equipped
vehicle, remove the cap from the pressure test port, place
some shop towels underneath to absorb sprayed fuel . . .
2 Fuel pressure relief (fuel-injected vehicles)
Refer to illustrations 2.5 and 2.7
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. Do not smoke
or alto w open flames or bare light bulbs in or near the work area. Also,
don't work in a garage where a natural gas appliance such as a water
heater or clothes dryer is present.
4-1
2.7 . . . then depress the valve in the test port with a small
screwdriver or pin punch - wear safety goggles during pressure
relief t o protect your eyes from spraying fuel
the manufacturer's instructions. If you don't have a remote starter
switch, you will need an assistant for the following procedures.
6 Disable the ignition coil by detaching the primary lead wires (see
Chapter 51.
7 With the fuel line directed into the container, have an assistant
turn the ignition key to Start and crank the engine for about ten seconds.
8 Fuel should be emitted from the fuel line in well-defined spurts.
If it isn't, there is a problem somewhere in the fuel delivery system.
The following tests will determine where the problem lies.
TBI-equipped vehicles
Pressure test
1
Refer to illustration 3. 10
Note: You will need a fuel pressure gauge, a hose restrictor and a section of flexible hose to perform the following procedures.
9 If the vehicle has a four-cylinder engine, detach the fuel return hose
at the fuel filter and plug the fitting on the filter.
10 Attach a pressure gauge, restrictor and flexible hose between the
fuel inlet fitting or the fuel filter and the carburetor (see illustration).
The fuel system of vehicles equipped with Throttle Body injection
(TBI) is only under pressure when the fuel pump is operating. As long
as the fuel pump is not operating, TBI fuel system components can
be removed without the need t o release system pressure.
MPl-equipped vehicles
2 The MPI system is under a constant fuel pressure of 9 to 19 psi.
Before attempting to service any fuel supply or return component on
vehicles equipped with this system, release the fuel pressure.
3 Detach the cable from the negative battery terminal.
4 Remove the fuel tank filler cap to relieve fuel tank pressure.
5 Remove the cap from the pressure test port on the fuel rail (see
illustration).
6 Place shop towels under the pressure test port to absorb fuel when
the pressure is released from the fuel rail.
7 Using a small screwdriver or pin punch, push the test port valve
in to relieve fuel pressure (see illustration). Absorb the spilled fuel with
the shop towels.
8 Remove the shop towels.
9 Install the cap on the pressure test port.
3 Fuel pumplfuel pressure
- check
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. Do not smoke
or a/lo w open flames or bare light bulbs in or near the work area. Also,
don't work in a garage where a natural gas appliance such as a water
hearer or clothes dryer is present.
Mechanical pump (carburetor equipped vehicles)
Quick check
1
:2.
3
of
4
5
Detach the cable from the negative battery terminal.
Remove the air cleaner assembly (see Section 7).
Detach the fuel inlet fitting from the carburetor and place the end
the inlet line in a metal or plastic container.
Attach the cable to the negative battery terminal.
Hook up a remote starter switch, if available, in accordance with
I
INLET LINE
(FROM FUEL PUMP)
3.10 The proper setup for the fuel pump pressure and
capacity tests (if you don't have a hose restrictor, a pair of
vise grips with padded jaws will work just as well)
4
The Motor Manual Guy
Chapter 4
4-2
Fuel and exhaust systems
PRESSURE TEST
PORT PLUG
ADJUSTING
SCREW
3.28 All system pressure tests on TBI-equipped vehicles require
the removal of the pressure test port plug from the throttle body
- in its place, install a special pressure test fitting (available at a
dealer parts department)
3.31 If the TBI system fuel pressure indicated on the test gauge
is incorrect. adjust it by turning the regulator adjusting screw turn the screw in (clockwise) t o increase pressure or out
(counterclockwise) t o decrease pressure
1 1 Position the flexible hose and restrictor so fuel can be discharged
into a graduated container.
12 Reattach the coil primary lead wires (the engine must be operated
for the following test).
13 Start the engine (or have your assistant start it), let it run at curb
idle rpm, then discharge the fuel into the container by momentarily
opening the hose restrictor.
1 4 Close the hose restrictor, allow the pressure to stabilize and note
the pressure. The gauge should indicate 4-to-5 psi for four-cylinder
engines and 6-to-7.5 psi for V6 engines.
a) If the pump pressure is not within specification, and the fuel lines
are in satisfactory condition, the pump is defective and should
be replaced.
b) If the pump pressure is within specifications, perform the following tests for capacity and vacuum.
exists in the fuel line or the in-tank fuel filter.
23 Detach the fuel inlet line at the fuel pump.
2 4 Install a T-fitting between the disconnected fitting and the fuel
pump inlet. Connect a vacuum gauge to the T-fitting.
25 Operate the engine at a speed of 1500 rpm for 3 0 seconds and
note the reading on the vacuum gauge (again, the gauge will not indicate any vacuum until the fuel in the carburetor float bowl has been
consumed and the pump begins t o operate at full capacity). The indicated vacuum should not exceed 3 in-Hg.
26 If the indicated vacuum exceeds the specified vacuum, check the
fuel line for a restriction. A partially clogged in-tank fuel filter can also
cause excess vacuum.
Capacity test
15 Operate the engine at curb idle rpm.
16 Open the hose restrictor and allow fuel to discharge into a
graduated container for 3 0 seconds, then close the restrictor. A t least
one pint of fuel should have been discharged.
a) If the pump volume is less than one pint, repeat the test with
an auxiliary fuel supply and, for four-cylinder engines, a replacement fuel filter.
b) If the pump volume conforms to the specified amount while using
the auxiliary fuel supply, look for a restriction in the fuel supply
line from the tank and check the tank vent to make sure it's working properly.
Direct connection vacuum test (V6 engines)
17 You will need a vacuum gauge to perform the direct connection
vacuum test. In this test, the vacuum test gauge is connected directly
to the fuel pump inlet t o test the pump's ability to create a vacuum.
18 Detach the fuel inlet line at the fuel pump.
19 Attach a vacuum gauge to the fuel pump inlet.
2 0 Operate the engine at curb idle speed and note the vacuum gauge
reading. It should indicate a vacuum of 1 0 in-Hg (the gauge will not
indicate a vacuum until the fuel in the carburetor float bowl has been
consumed and the pump begins to operate at full capacity).
21 If the pump vacuum is not within specification, the pump is defective. Replace it (see Section 4).
Electrical pump (fuel injected vehicles)
TBI pressure test
Refer to illustrations 3.28 and 3.3 1
27 Detach the cable from the negative battery terminal.
28 Remove the pressure test port plug from the throttle body (see
illustration).
29 Install a pressure test fitting (available at a Jeep parts department)
in place of the test port plug.
3 0 Attach a 0-to-30 psi fuel pressure gauge to the pressure test fitting
(don't use a carburetor type 0-to-1 5 psi gauge).
31 Start the engine and let it idle. The pressure gauge should read
14-to-1 5 psi. If the pressure is incorrect, adjust it by turning the regulator adjusting screw (see illustration) to obtain the correct fuel pressure.
Turn the screw at the bottom of the regulator in (clockwise) to increase
pressure or out (counterclockwise) to decrease pressure.
3 2 If the fuel pressure is considerably higher than specified, and adjusting the regulator fails to lower it to the specified level, inspect the fuel
return line for blockage.
3 3 If the fuel pressure is considerably below specification and adjusting
the regulator fails to raise it to the specified level, momentarily pinch
off the fuel return line and recheck the pressure.
a) If the fuel pressure has risen, replace the pressure regulator (see
Section 13).
b) If the pressure has not risen, check the fuel filter (see Chapter
1) and fuel supply line for blockage.
Indirect connection vacuum test (V6 engine)
MPI pressure test
22 You will need a vacuum gauge and a T-fitting to perform the indirect
connection vacuum test. In this test, a vacuum gauge is connected
by a T-fitting into the pump inlet to determine whether an obstruction
Refer to illustrations 3.35, 3.36 and 3.4 1
3 4 The MPI fuel system employs a vacuum-assisted pressure reguFuel pressure should be about eight to ten psi higher with the
The Motor Manual Guy
Chapter 4
Fuel and exhaust systems
4-3
3.36 Detach the vacuum tube from the fuel pressure regulator,
start the vehicle and note the gauge reading - with the vacuum
line detached, fuel pressure should be about 39 psi
3.35 To test the MPI fuel system pressure, you will need
to attach a 0-to-60 psi pressure gauge to the test port
pressure fitting on the fuel rail
vacuum line attached to the regulator than with the vacuum line disconnected. Fuel system pressure should be 31 psi with the vacuum line
attached to the regulator and 3 9 psi with the line detached.
3 5 Attach a 0-to-60 psi fuel pressure gauge to the test port pressure
fitting on the fuel rail (see illustration),
36 Detach the vacuum tube from the fuel pressure regulator (see illustration).
37 Start the engine.
38 Note the gauge reading. With the vacuum line detached, fuel
pressure should be about 39 psi.
3 9 Attach the vacuum line to the pressure regulator. Note the gauge
reading. Fuel pressure should be about 31 psi.
4 0 If the indicated fuel pressure is not about 8-to-1 0 psi higher with
the vacuum line removed from the regulator, inspect the pressure
regulator vacuum line for leaks, kinks and blockage.
41 If the fuel pressure is below the specified level, momentarily pinch
off the hose section of the return line (see illustration). The fuel pressure
will rise to 95 psi when the fuel return line is pinched shut, so turn
off the engine immediately after pinching off the fuel return line.
a) If the fuel pressure remains below specifications, inspect the fuel
supply line, fuel filter (see Chapter 1) and fuel rail inlet (see Section 14) for blockage.
b) If the fuel pressure rises, replace the regulator.
c) If the fuel pressure is above specification, inspect the fuel return
line for kinks and blockage.
MPI fuel pressure leak down test
4 2 If an abnormally long cranking period is required to restart a hot
engine after the vehicle has been shut down for a short period of time,
the fuel pressure may be leaking past the fuel pressure regulator or
the check valve in the outlet end of the fuel pump.
43 With the engine off, attach a gauge capable of reading 0-to-1 0 0
psi to the pressure test port fitting on the fuel rail.
4 4 Start the vehicle and let the engine idle. Check the fuel pressure
reading on the gauge. The fuel pressure should be within the specifications noted above.
4 5 Shut the engine off. Note the fuel pressure reading on the gauge.
Leave the fuel pressure gauge connected. Allow the engine to sit for
3 0 minutes, then compare the fuel pressure reading on the gauge to
the reading you took when you shut down the engine. A drop of 0-to-20
psi (to the 19-to-39 psi range) is acceptable. If the fuel pressure drop
is within specification, the fuel pump outlet check valve and the fuel
pressure regulator are both operating normally. If the fuel pressure drop
is greater than 20 psi, restart the vehicle, let the engine idle and momen-
4
3.41 If the fuel pressure is below the specified level,
momentarily pinch off the hose section of the fuel return
line - fuel pressure will rise t o 95 psi when the fuel return
line is pinched, so turn the engine off immediately after
pinching off the fuel return line
tarily pinch off the hose section of the fuel return line. The fuel pressure
will rise to 9 5 psi when the fuel return line is pinched off, so shut the
engine down immediately after pinching off the fuel return line. Note
the pressure reading on the gauge. Allow the engine to sit for 3 0
minutes. Take another reading and compare it to the reading you took
when you first shut down the engine.
a) If the fuel pressure has dropped about 2 0 psi, replace the fuel
pressure regulator.
b) If the fuel pressure has dropped considerably more than 20 psi,
fuel pressure is bleeding off past the outlet check valve in the
fuel pump. Replace the pump.
Capacity test
4 6 Remove the cap from the pressure test port in the fuel rail (see
illustration 2.5).
47 Attach a 0-to-60 psi fuel pressure gauge to the pressure fitting.
4 8 Start the engine. Pressure should be about 31 psi with the vacuum
hose attached to the pressure regulator and 39 psi with the vacuum
hose removed from the pressure regulator (see illustration 3.36). If
The Motor Manual Guy
Chapter 4
4-4
Fuel and exhaust systems
4.4b
4.4a Installation details of the mechanical fuel pump used
on V6 models
inlet line
2 Fuel pump
3 Gasket
4 Actuating rod (this may fall
out of engine block when fuel
pump is removed)
Installation details of the mechanical fuel pump used
on four-cylinder models
the pressure is not within specifications, one of the following problems
exists:
a) There is a kink or other restriction in a fuel supply or return line
hose. Inspect the lines and hoses.
b) The fuel pump flow rate is not sufficient. Take the vehicle to a
dealer service department for proper checking of the fuel pump
flow rate.
c) The fuel pressure regulator is malfunctioning. Take the vehicle
to a dealer service department for proper checking. (See Section 14 to replace the regulator).
4
Fuel pump - removal and installation
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. Do not smoke
or allow open flames or bare light bulbs in or near the work area. Also,
don't work in a garage where a natural gas appliance such as a water
heater or clothes dryer is present.
Mechanical pump
4.12 To remove the electric fuel pump from the fuel tank,
detach the hoses and the electrical connector (arrows) - label
the hoses so you can return them to their original locations
Refer to illustrations 4.4a and 4.4b
1 Detach the cable from the negative battery terminal.
2 Remove the fuel tank filler cap to relieve fuel pressure.
3 Wrap shop towels around the fuel pump inlet hose and outlet line
fitting to absorb any fuel spilled during fuel pump removal.
4 Detach the fuel inlet hose and outlet line fitting from the fuel pump
(see illustrations).
5 Unscrew the fuel pump mounting bolts and remove the fuel pump
and gasket.
6 Carefully scrape away any old gasket material from the fuel pump
and engine block sealing surfaces.
7 lnstallation is the reverse of removal. Be sure to use a new gasket
and tighten the fuel pump bolts t o the specified torque.
Electric pump
Removal
4.15
To loosen the lock ring for the fuel
sending
unit assembly, turn it counterclockwise - if the ring is
difficult to loosen, tap it loose with a wood dowel or brass
punch and a small mallet (DO NOT use a steel punch, or
you could cause an explosion!)
Refer to illustrations 4.12, 4.15, 4.20a and 4.20b
Note: The following procedure requires removal of the fuel tank.
8 Remove the fuel tank filler cap to relieve fuel tank pressure.
9 Relieve the fuel system pressure (see Section 2).
10 Detach the cable from the negative battery terminal.
11 Raise the vehicle and place it securely on jackstands.
12 Disconnect the fuel vent, supply and return hoses from the fittings on the fuel purnplsending unit (see illustration).
13 Detach the fuel pumplsending unit electrical harness connector
from the main harness.
14 The fuel pumplsending unit assembly is located inside the fuel tank.
It's held in place by a cam lock ring mechanism consisting of an inner ring
with three locking cams and an outer ring with three retaining tangs.
15 To unlock the fuel pumplsending unit assembly, turn the inner ring
counterclockwise until the locking cams are free of the retaining tangs. If
the rings are locked together too tightly to release them by hand, gently
knock them loose with a wood dowel or a brass punch and hammer (see
illustration). Warning: Do not use a steel punch to knock the lockrings
The Motor Manual Guy
Chapter 4
WIRE TERMINALS
4_5
Fuel and exhaust systems
OUTLEl
HOSE
OUTLEl
HOSE
I
TERMINALS
TBI
FUEL
PUMP
4.20a
TOP MOUNTING
BRACKET NUT
BRACKET NUT
The TBI fuel pumplsending unit assembly
FUEL
PUMP
4.20b
loose. A spark could cause an explosion!
16 Extract the fuel pump/sending unit assembly from the fuel tank. The
fuel level float and sendina unit are delicate. Do not bump them into the
lockring during removal or the accuracy of the sending unit may be affected.
17 lnspect the condition of the gasket around the mouth of the lockring
mechanism. If it's dried, cracked or deformed, replace it.
18 lnspect the inside of the tank. Have it cleaned by a radiator shop if
sediment is present.
19 If you are replacing the fuel pump, make sure you get the right pump.
The TBI and MPI pumps look alike, but they're NOT interchangeable.
Disassembly
20 Remove and discard the fuel pump inlet filter (see illustrations).
21 Detach the fuel pump wires (the wire ends are different sizes and cannot be connected to the wrong terminal).
22 Detach the fuel pump outlet hose and clamp. Replace the hose if it
shows signs of wear or deterioration.
23 Remove the fuel pump top mounting bracket nut. Remove the fuel
pump.
The MPI fuel pump/sending unit assembly
not work in a garage if a natural gas-type appliance with a pilot light
is present. While performing any work on the fuel rank, wear safety
glasses and have a dry chemical (Class BJ fire extinguisher on hand
If you spill any fuel on your skin, rinse i t off immediately with soap
and water.
Remove the fuel tank filler cap to relieve fuel tank pressure.
2 If the vehicle is fuel-injected, relieve the fuel system pressure (see
Section 2).
3 Detach the cable from the negative terminal of the battery.
4 If the tank still has fuel in it, you can drain it at the fuel supply
line after raising the vehicle.
5 Raise the vehicle and place it securely on jackstands.
6 Disconnect all hoses and the electrical connector for the fuel gauge
sending unit and electric fuel pump (if equipped) (see illustrations).
Carefully label all hoses so you can reinstall them in their original
locations.
Reassembly
24 Install a new inlet filter.
25 Place the fuel pump top mounting bracket over the top of the pump.
26 Position the fuel pump in the lower bracket. Slide the stud of the top
bracket through the hole in the fuel pump side bracket. Tighten the fuel
pump top mounting nut.
27 Install the fuel pump outlet hose. Secure it with new clamps.
28 Connect the wire terminals to the motor.
Installation
29 Insert the fuel pumpisending unit assembly into the fuel tank.
30 Turn the inner lock ring clockwise until the locking cams are fully engaged by the retaining tangs. If you have installed a new O-ring type rubber gasket, it may be necessary to push down on the inner lock ring until
the locking cams slide under the retaining tangs.
31 Attach the cable to the negative battery terminal.
32 Start the engine and check carefully for leaks.
5
Fuel tank
removal and installation
Refer to illustrations 5.6a and 5.6b
Note: The following procedure is much easier to perform i f the fuel
tank is empty. Run the engine until the tank is empty.
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. Do not smoke
or allow open flames or bare light bulbs near the work area. Also, do
5.6a
Fuel tank components (Comanche)
1 Fuel feed line
2 Fuel return line
3 Fuel gauge sending unit
(and, on TB/IMP/ models,
fuel pump)
4 Sending unit/fuel pump
electrical connector
5 Retaining strap nuts
6 Protective shield
·-----=----The Motor Manual Guy
4-6
~
@
5.6b
2
3
4
5
6
7
8
9
10
Fuel tank components
(Cherokee)
Retaining strap nuts
Fuel feed line
Fuel return line
Fuel filler hose
Filler vent hose
Fuel gauge sending unit
electrical connector
Protective shield
Fuel tank
Vapor vent hose
Fuel pump (TB/ and
MPI models)
4
7.2a Air cleaner assembly
components - exploded view
(four-cylinder engine)
2
3
4
5
6
11
7
8
9
101
1
12
13
14
15
16
Cover
Ambient air duct adapter
Flexible duct
Adapter
Heat s to ve
Heated air tube
Vacuum motor
Filter element
Elbow
PCV filter retainer
Reversed
G
eIay valve
rommet
Stud
Check valve
Air cleaner bod
Thermal switc/
The Motor Manual Guy
Chapter 4
Fuel nd exhaust systems
7
8
Siphon the fuel from the tank at the fuel feed line, not the return line.
Support the fuel tank with a floor jack or jackstands. Position a
piece of wood between the jack head and the fuel tank to protect the
tank.
9 Disconnect the fuel tank retaining straps and pivot them down until
they are hanging out of the way.
10 Remove the tank from the vehicle.
1 1 Installation is the reverse of removal.
6
4-7
dangerous work. Even after cleaning and flushing of the fuel system,
explosive fumes can remain and ignite during repair of the tank.
2 If the fuel tank is removed from the vehicle, it should not be placed
in an area where sparks or open flames could ignite the fumes coming
out of the tank. Be especially careful inside garages where a natural
gas type appliance is located, because the pilot light could cause an
explosion.
7 Air cleaner - removal and installation
Fuel tank cleaning and repair - general information
Four-c ylinder and V6 engines
1 All repairs to the fuel tank or filler neck should be carried out by
a professional who has experience in this critical and potentially
Refer to illustrations 7.2a and 7.2b
1 Detach the cable from the negative terminal of the battery.
2 Detach the flexible ambient air duct from the air cleaner housing
snorkel (see illustrations).
3 Remove the wing nut from the cover and remove the cover and
filter element. Inspect the element for contamination by dirt and moisture. Replace it if necessary (see Chapter 1 ).
4 Clearly label, then detach, all hoses from the air cleaner housing.
5 Remove the air cleaner housing assembly.
6 Installation is the reverse of removal.
lnline six-c ylinder engine
Refer to illustration 7.8
7 Detach the cable from the negative battery termi .al.
8 Loosen the hose clamp at one end and remove the three attaching
screws at the other end of the flexible air duct between the air cleaner
housing and the throttle body (see illustration). Remove the duct.
9 Clearly label, then detach, all vacuum hoses from the air cleaner
housing.
3
1
4
7 . 8 To remove the flexible air duct on inline six-cylinder
engines, loosen the hose clamp at one end and remove the
three attaching screws (arrows) from the other end - the
third attaching screw is hidden by the duct i n this photo
7.2b
1
2
3
4
5
6
Air cleaner assembly components - exploded view
(V6 engine)
Air cleaner cover
PCV valve filter
Thermal switch
Check valve
Vacuum motor
Heated air tube
7
8
9
10
11
12
Ambient air duct
Reverse delay valve
Trap door assembly
Reverse delay valve
Thermal vacuum switch
Filter element
1 0 Detach the heat riser tube from the air cleaner housing.
1 1 Remove the upper half of the air cleaner housing lid, then remove
the air filter element.
12 Remove the two bolts and one nut from the floor of the air cleaner
housing. Remove the housing.
1 3 Installation is the reverse of removal.
8 Carburetor - adjustments
1 The carburetors used on the vehicles covered by this manual are
protected by a Federally-mandated extended warranty (at the time this
manual was written, the warranty was for 5 years/50,000 miles,
The Motor Manual Guy
Chapter 4
4-8
Fuel and exhaust systems
whichever comes first - see your dealer for details).
2 We don't recommend carburetor adjustments while it's still under
warranty. If you are having problems related t o fuel delivery - and
you have eliminated all other parts of the fuel delivery system as possible causes - take the vehicle t o a dealer and have the carburetor professionally serviced.
3 Unless you really know what you're doing, w e don't recommend
you attempt t o adjust an out-of-warranty carburetor either.The carburetors on these vehicles are expensive, complex and tricky t o adjust.
The adjustments are also totally interrelated, so it's impossible t o do
certain adjustments unless you have already done several others. Finally,
by the time adjuistments become necessary, the carburetor will probably be approaching the end of its service life and will be impossible
t o adjust t o a like-new state o f tune. A t this point, you're better o f f
buying a rebuilt or n e w carburetor.
9 Carburetor - removal and installation
Warning: Gasoline is extremely flammable so extra precautions must
be taken when working on any part of the fuels ystern. DO NOT smoke
or allow open flames or bare light bulbs in or near the work area. Also,
don't work in a garage if a natural gas appliance such as a water heater
or clothes dryer is present.
Remo val
1 Detach the cable from the negative battery terminal.
2 Remove the fuel filler cap t o relieve fuel tank pressure.
3 Remove the air cleaner from the carburetor. Be sure t o label all
vacuum hoses attached t o the air cleaner housing.
4 Disconnect the throttle cable from the throttle lever.
5 If the vehicle is equipped w i t h an automatic transmission, disconnect the TV cable from the throttle lever (see Chapter 7, Part B).
6 Clearly label all vacuum hoses and fittings, then disconnect the
hoses.
7 Disconnect the fuel line from the carburetor.
8 Label the wires and terminals, then unplug all wire harness connectors.
9 Remove the mounting fasteners and detach the carburetor from
the intake manifold. Remove the carburetor mounting gasket. Stuff
a shop rag into the intake manifold openings.
Installation
1 0 Use a gasket scraper t o remove all traces o f gasket material and
sealant from the intake manifold (and the carburetor, if it's being
reinstalled), then remove the shop rag from the manifold openings.
Clean the mating surfaces w i t h lacquer thinner or acetone.
11 Place a n e w gasket on the intake manifold.
1 2 Position the carburetor on the gasket and install the mounting
fasteners.
1 3 To prevent carburetor distortion or damage, tighten the fasteners
t o the specified torque in a criss-cross pattern, 114-turn at a time.
1 4 The remaining installation steps are the reverse of removal.
1 5 Check and, if necessary, adjust the idle speed (see Chapter 1).
1 6 If the vehicle is equipped w i t h an automatic transmission, refer
t o Chapter 7, Part B for the T V cable adjustment procedure.
1 7 Attach the negative battery cable.
18 Start the engine and check carefully for fuel leaks.
10
Carburetor
diagnosis and overhaul
Refer to illustrations 10.Ba, 7 O.Bb and 10.Bc
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. DO NOTsmoke
or a/lo w open flames or bare light bulbs in or near the work area. Also,
don't work in a garage if a natural gas appliance such as a water heater
or clothes dryer is present.
Diagnosis
1 A thorough road test and check of carburetor adjustments should
be done before any major carburetor service work. Specifications for
some adjustments are listed on the Vehicle Emissions Control In formation (VEG/) label found in the engine compartment.
2 Carburetor problems usually show up as flooding, hard starting,
stalling, severe backfiring and poor acceleration. A carburetor that's
leaking fuel and/or covered with wet looking deposits definitely needs
attention.
3 Some performance complaints directed at the carburetor are actually a result of loose, out-of-adjustment or malfunctioning engine or
electrical components. Others develop when vacuum hoses leak, are
disconnected or are incorrectly routed. The proper approach t o analyzing carburetor problems should include the following items:
a) lnspect all vacuum hoses and actuators for leaks and correct installation (see Chapters 1 and 6).
b) Tighten the intake manifold and carburetor mounting nutslbolts
evenly and securely.
c) Perform a cylinder compression test (see Chapter 2).
d) Clean or replace the spark plugs as necessary (see Chapter 1).
e) Check the spark plug wires (see Chapter 1).
f) lnspect the ignition primary wires.
g) Check the ignition timing (follow the instructions printed on the
Emissions Control Information label ).
h) Check the fuel pump and fuel pressure (see Section 3).
i) Check the heat control valve in the air cleaner for proper operation (see Chapter 1 ).
j) Checklreplace the air filter element (see Chapter 1).
k) Check the PCV system (see Chapter 6).
I) Checklreplace the fuel filter (see Chapter 1 ). Also, the filter in
the tank could be restricted.
m) Check for a plugged exhaust system.
n) Check EGR valve operation (see Chaper 6).
o) Check the choke- it should be completely open at normal engine
operating temperature (see Chapter 1).
p) Check for fuel leaks and kinked or dented fuel lines (see Chapters
1 and 4)
q) Check accelerator pump operation w i t h the engine off (remove
the air cleaner cover and operate the throttle as you look into
you should see a stream of gasoline enter
the carburetor throat
the carburetor).
r) Check for incorrect fuel or bad gasoline.
s) Check the valve clearances (if applicable) and camshaft lobe lift
(see Chapter 2)
t) Have a dealer service department or repair shop check the electronic engine and carburetor controls.
4 Diagnosing carburetor problems may require that the engine be
started and run w i t h the air cleaner off. While running the engine
without the air cleaner, backfires are possible. This situation is likely
t o occur if the carburetor is malfunctioning, but just the removal of
the air cleaner can lean the fuel/air mixture enough t o produce an engine
backfire. Warning: Do not position any part of your body, especially
your face, directly over the carburetor during inspection and servicing
procedures. Wear eye protection!
Overhaul
5 Once it's determined that the carburetor needs an overhaul, several
options are available. If you're going t o attempt t o overhaul the carburetor yourself, first obtain a good quality carburetor rebuild kit (which
will include all necessary gaskets, internal parts, instructions and a parts
list). You'll also need some special solvent and a means of blowing
out the internal passages of the carburetor w i t h air.
6 A n alternative is t o obtain a n e w or rebuilt carburetor. They are
readily available from dealers and auto parts stores. Make absolutely
sure the exchange carburetor is identical t o the original. A tag is usually
attached t o the top o f the carburetor or a number is stamped on the
float bowl. It will help determine the exact type of carburetor you have.
When obtaining a rebuilt carburetor or a rebuild kit, make sure the kit
or carburetor matches your application exactly. Seemingly insignificant
differences can make a large difference in engine performance.
7 If you choose t o overhaul your o w n carburetor, allow enough time
t o disassemble it carefully, soak the necessary parts in the cleaning
solvent (usually for at least one-half day or according t o the instructions listed o n the carburetor cleaner) and reassemble it, which will
usually take much longer than disassembly. When disassembling the
carburetor, match each part with the illustration in the carburetor kit
and lay the parts out in order on a clean work surface. Overhauls by
The Motor Manual Guy
Chapter 4
Fuel and exhaust systems
inexperienced mechanics can result in an engine which runs poorly or
not at all. To avoid this, use care and patience when disassembling
the carburetor so you can reassemble it correctly.
8 Because carburetor designs are constantly modified by the
manufacturer in order to meet increasingly more stringent emissions
4-9
regulations, it isn't feasible to include a step-by-step overhaul of each
type. You'll receive a detailed, well illustrated set of instructions with
any carburetor overhaul kit; they will apply in a more specific manner
to the carburetor on your vehicle. Exploded views of the three carburetors are included here (see illustrations).
2
4
\
~
~
~
~
I
.
J\__
16
17
10.Sa
Vacuum break
2 Air horn
3 Choke plate
4 Sole-Vac throttle
positioner
5 Choke assembly
\,,
An exploded view of the YFA carburetor used on earlier four-cylinder engines
6 Accelerator pump assembly
7 Idle mixture screw
with O-ring
8 Throttle plate
9 Main body
10 Accelerator pump check
ball and weight
1 Main metering jet
12 Float assembly
13 Mixture control solenoid
14 Low speed jet
15 Accelerator pump vent valve
16 Wide open throttle
(WOT) switch
17 Throttle shaft and lever
18 Throttle body
---=--=--=
The Motor Manual Guy
4-10
10.Sb
An exploded view of the Model 2SE carburetor
used on 49-State V6 engines
Air horn components
I Air horn long screw (2)
2 Air horn large screw
3 Air horn short screw (3)
4 Air horn medium screw
5 Vent stack assembly
6 Hot idle compensator
screw (2)
7 Hot idle compensator
8 Hot idle compensator screw
9 Air horn assembly
10 Air horn gasket
I I Pump retainer
12 Pump stem seal
13 Stem seal retainer
Choke components
14 Primary vacuum break and
bracket assembly
15 Vacuum break
attaching screw
16 Air valve rod bushing
17 Air valve rod retainer
18 Vacuum break primary hose
19 Air valve rod
20 Fast idle cam rod
2 7 lntermediate choke
shaft/lever/rod assembly
22 lntermediate choke
shaft rod bushing
23 lntermediate choke
shaft rod retainer
24 Secondary vacuum break
and bracket assembly
25 Choke cover and
coil assembly
26 Choke lever screw
27 Choke lever and
contact assembly
28 Choke housing
29 Choke housing screw (2)
30 Stat cover retainer kit
3 1 Vacuum break attaching
screw (2)
9
33
//
Float bowl components
32 Float bowl assembly
33 Fuel inlet nut
34 Fuel inlet nut gasket
35 Fuel inlet filter
36 Fuel filter spring
37 Float assembly
38 Float hinge pin
39 Float bowl insert
40 Needle and seat assembly
4 1 Pump return spring
42 Pump assembly
43 Main metering jet
44 Main metering assembly rod
45 Pump discharge ball
46 Pump discharge spring
47 Pump discharge
spring retainer
48 Power piston assembly
49 Power piston spring
Throttle body components
50 Throttle body gasket
51 Throttle body assembly
52 Pump rod
53 Cam screw clip
l
54
55
56
57
58
Cam screw
Throttle stop screw spring
Throttle stop screw
Idle needle and spring
Throttle body attaching screw (4)
59 Idle speed kick actuator nut
60 Idle speed kick
actuator retainer
6 1 ldle speed kick actuator
The Motor Manual Guy
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4-11
10.8c
An exploded view of the E2SE carburetor used on
California V6 engines
Air horn components
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Mixture control
(MIC) solenoid
Solenoid attaching
screw assembly
MIC solenoid-to-air
horn gasket
MIC solenoid spacer
MIC solenoid-to-float
bowl seal
MIC solenoid seal retainer
Air horn assembly
Air horn-to-float bowl gasket
Air horn-to-float bowl
short screw
Air horn-to-float bowl
long screw
Air horn-to-float bowl
large screw
Vent stack and
screen assembly
Vent stack attaching screw
Pump stem seal
Pump stem seal retainer
TPS plunger seal
TPS plunger seal retainer
TPS actuator plunger
12
0
r·
~~
r"
21
/
/
/
/1/~8
I
,1
33
/
38
\_
~q
I
~("
,~37
I
l,_ 41-.'.:.J
Chok e components
19 Vacuum break and
bracket assembly
20 Vacuum break
primary hose
21 Vacuum break tee
22 ldle speed solenoid
23 ldle speed solenoid
retainer
24 ldle speed solenoid
attaching nut
25 Vacuum break bracket
attaching screw
26 Air valve link
27 Air valve link bushing
28 Air valve link retainer
29 Fast idle cam link
29A Fast idle cam link
298 Link retainer
29C Link bushing
30 Vacuum break hose
31 Intermediate choke
shaft/lever/link assembly
32 Intermediate choke
link bushing
33 Intermediate choke
link retainer
34 Secondary vacuum break
and link ssembly
35 Vacuum break
attaching screw
36 Electric choke cover
and coil assembly
37 Choke lever attaching screw
38 Choke coil lever assembly
39 Choke housing
40 Choke housing
attaching screw
Choke cover retainer kit
4··
Float
42
43
44
45
46
47
48
48A
49
50
51
52
53
54
55
56
57
58
59
bowl components
Fuel inlet nut
Fulet inlet nut gasket
Fuel inlet filter
Fuel filter spring
Float and lever assembly
Float hinge pin
Float bowl upper insert
Float bowl lower insert
Needle and seat assembly
Pump return spring
Pump plunger assembly
Primary metering jet assembly
Pump discharge ball retainer
Pump discharge spring
Pump discharge ball
TPS adjusting spring
Throttle Position
Sensor (TPS)
Float bowl assembly
Float bowl gasket
Throttle body components
60 Pump link retainer
6 1 Pump link
62 Throttle body assembly
63 Cam screw clip
64 Fast idle cam screw
65 Idle needle and
spring assembly
66 Throttle body-to-float
bowl screw
67 Vacuum break bracket
attaching screw
68 Idle stop screw
69 Idle stop screw spring
70 Insulator flange gasket
ll__ _ _ _ _ _ _ _ _ _ _ _ __
The Motor Manual Guy
Chapter 4
4-12
Fuel and exhaust systems
11 Fuel injection system - general information
QUICK-CONNECT FITTINGS
Fuel-injected vehicles are equipped with either a Throttle Body Injection (TBI) system (four-cylinder engine) or a Multi-Point lnjection
(MPI) system (inline six-cylinder engine). Both systems use an Electronic Control Unit (ECU) to control pulse width.
The pulse width is the period of time during which the injector is
energized (squirts fuel). The Electronic Control Unit (ECU), opens and
closes the injector's ground path to control fuel injector pulse width
and thus meter the amount of fuel available to the engine. By continually
altering the pulse width, the ECU adjusts the air-fuel ratio for varying
operating conditions. For more information about the ECU, see Chapter 6.
Throttle body injection (TBI) is a single-point system that injects fuel
through one electrically operated fuel injector into the throttle body
above the throttle plate.
Multi-Point lnjection (MPI) is a multi-injector, sequential system: Fuel
is iniected into the intake manifold uostream of each intake valve in
precisely metered amounts through electrically operated injectors. The
injectors are energized in a specific sequence by the Electronic Control
Unit (ECU). There is no injector in the throttle body itself, as in a TBI
system; the six injectors are installed in the intake manifold. They
receive pressurized fuel from a fuel rail attached to their upper ends.
System fuel pressure on both systems is provided by an in-tank electric fuel pump and is controlled by a spring and vacuum-assisted fuel
pressure regulator.
12.9a
Typical under body quick-connect fittings (TBIequipped vehicle)
12 Fuel lines and fittings - inspection and replacement
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. Don't smoke
or allow open flames or bare light bulbs in or near the work area. Also,
don't work in a garage where a natural gas appliance such as a water
heater or clothes dryer is present.
Inspection and replacement
Refer to illustration 12.6
1
Check the fuel lines and all fittings and connections for cracks,
leakage and deformation.
2 Check the fuel tank vapor vent system hoses and connections for
looseness, sharp bends and damage.
3 Check the fuel tank for deformation, cracks, fuel leakage and tank
band looseness.
4 Check the filler neck for damage and fuel leakage.
5 Repair or replace any damaged or deteriorated hoses or lines. If
your vehicle is equipped with fuel injection, see below for information
on replacing fuel line fittings.
6 When attaching hoses to metal lines, overlap them as shown (see
illustration).
1/4-INCH
_ _____...,....~---PIPE
_._
12.9b
HOSE
I
_,.--..,
CLIP
1/8-INCH
12.6 When attaching a section of rubber fuel hose t o a metal
fuel line, be sure t o overlap the hose as shown and secure it to
the line with a new hose clamp of the proper type
Quick-connect fitting locations (MPI-equipped vehicle)
Fuel line fitting replacement (fuel injected vehicles)
Refer to illustrations 12.9a, 12.9b, 12. 10, 12.13 and 12. 14
7 Remove the fuel tank filler cap to relieve fuel tank pressure.
8 If the vehicle is equipped with Multi Point lnjection (MPI), relieve
the system pressure before proceeding (see Section 2). If the vehicle
is equipped with Throttle Body lnjection (TBI), system pressure is bled
off when the fuel pump is not operating
you can disconnect fuel
hoses and lines as soon as you have turned off the engine.
9 All fuel injected engines use special quick-connect fuel line fittings.
On TBI-equipped vehicles, the fittings are located at the throttle body
ends of the nylon reinforced hoses which connect the throttle body
to the fuel supply and return lines and under the vehicle along the left
frame rail (see illustration). On MPI-equipped engines, they're located
at the fuel rail inlet port and at the connection between the fuel return
line and the fuel return hose (see illustration).
10 The fittings consist of t w o O-rings, a spacer between the t w o 0-
The Motor Manual Guy
Chapter 4
\
FITTING
SPACER
Fuel and exhaust systems
TAB
4-13
REPLACEMENT
\
QUICK-CONNECT
FITTING
O-RINGS
-
/
RETAINER
12.13 The new O-rings, spacer and retainer are already
installed on a disposable plug - t o install them in the
quick-connect fitting, insert the plug into the fitting until
you hear a click, then withdraw and discard the plug
12.10 Cutaway of quick-connect fitting showing
relationship of O-rings, spacer and retainer
QUICK-CONNECT
FITTING
DISPOSABLE PLUG
FUEL LINE
I
4
12.14 Once you've installed the new O-rings, spacer and
retainer, push the fuel line into the fitting until you hear a click
rings and a retainer (see illustration).
1 Every time you disconnect a quick-connect fitting, you must replace
the O-rings, spacer and retainer. These parts are available as a repair
kit through any dealer parts department.
12 To disconnect a quick connect fitting, simply pinch the t w o retainer tabs together and pull the fitting apart. The retainer, O-rings and
spacer will come out of the fitting when you pull the fuel lines apart.
Discard these parts.
1 3 The replacement kit (O-rings, spacer and retainer) is installed on
a disposable plastic plug. To replace these parts, push the disposable
plug assembly into the quick connect fitting until you hear a "click"
sound (see illustration). Then grasp the end of the disposable plug and
pull it out of the fitting.
14 Push the fuel line into the refurbished quick-connect fitting until
you hear a "click" sound (see illustration).
15 Verify that the connection is secure by pulling firmly back on the
fuel line. It should be locked in place.
13.2
Detach the vacuum hoses, release the mounting
clips and remove the upper bonnet
THROTTLE BODY
1 3 Throttle body (TBl-equipped vehicles) - removal
and installation
Refer to illustrations 13.2, 13.3, 3.6 and 13.8
1 Detach the cable from the negative battery terminal.
2 Detach the vacuum hoses from the throttle body upper bonnet (see
illustration). Release the mounting clips and remove the upper bonnet.
3 Remove the three mounting nuts and lift off the lower bonnet (see
illustration).
I
13.3
Remove the mounting nuts, then detach the lower bonnet
The Motor Manual Guy
Chapter 4 Fuel and exhaust systems
4-1 4
NUTS (4)
13.8
13.6 Remove the
accelerator cable and
return spring
4 Disconnect the ISA motor harness connector (see illustration
13.33).
5 Detach the fuel supply and return lines from the throttle body.
6 Remove the accelerator cable and return spring (see illustration).
7 Detach the wire harness connector from the injector by compressing the lock tabs and lifting up.
8 Identify and label the vacuum tubes at the back of the throttle body
so you can install them in their original locations. Detach the vacuum
tubes from the throttle body (see illustration).
9 Detach the TPS connector (two connectors on automatics).
10 Remove the throttle body mounting nuts (see illustration 13.8)
and remove the throttle body.
11 Remove any old gasket material or dirt from the mating surfaces
of the intake manifold and the throttle body.
12 If you are replacing the throttle body assembly, remove the ISA
motor and throttle position sensor. Install them on the replacement
throttle body and adjust them (see Section 14).
13 Installation is the reverse of removal. Be sure t o use a new gasket
and tighten the mounting nuts to the specified torque.
ldentify and tag the vacuum tubes at the back of the
throttle body, then detach them
1 4 Throttle body injection (TBI)
system - component replacement
Fuel body
Refer to illustration 14.3
1 Detach the cable from the negative battery terminal.
2 Remove the throttle body (see Section 13).
3 Remove the three Torx head screws that attach the fuel body to
the throttle body (see illustration).
4 Remove the original gasket and discard it.
5 Installation is the reverse of removal.
Fuel injector
Refer to illustrations 14.8, 14.9 and 14.10
Removal
6
7
8
Remove the throttle body upper bonnet (see Section 13).
Remove the throttle body lower bonnet (see Section 13).
Detach the injector connector (see illustration) by compressing the
GASKET
MOUNTING
SCREWS
THROTTLE
BODY
14.3
An exploded view of the fuel body assembly
14.8
To remove the injector connector on TBI-equipped
vehicles, compress the tabs and lift up
The Motor Manual Guy
Chapter 4
Fuel and exhaust systems
4-15
lock tabs and lifting up.
9 Remove the screws and lift off the retainer (see illustration).
1 0 Using a small pair of pliers, gently grasp the center collar of the
injector and carefully remove the injector by rocking it back and forth
while lifting up (see illustration). Caution: Do not twist the injector during removal or its locating tab will be damaged.
1 1 Remove and discard the centering ring and upper and lower O-rings
(see illustration 14.9). Caution: Do not re-use these rings or fuelleakage
and poor driveability may occur.
RETAINER
Installation
12 Lubricate the replacement lower O-ring with light oil. lnstall the
replacement lower O-ring in the bottom of the fuel injector housing bore.
13 Lubricate the replacement upper O-ring with light oil. Install it in
the fuel injector housing bore.
1 4 lnstall the centering ring on top of the upper O-ring.
15 Align the locating tab on the bottom of the injector (see illustration 14.9) with the slot in the bottom of the housing and install the
injector.
16 lnstall the retainer and tighten the screws securely.
1 7 Attach the injector connector.
18 lnstall the lower and upper bonnets.
1 9 Attach the negative battery cable.
UPPERO-RING
Fuel pressure regulator
14.9
An exploded view of TBI fuel injector components
Refer to illustration 74.2 7
2 0 Remove the throttle body (see Section 13).
21 Remove the pressure regulator mounting screws (see illustration).
Warning: The regulator is under spring pressure. To prevent possible
injury from the regulator flying off, keep the regulator forced against
the throttle body while you're removing the screws.
2 2 Remove the housing, spring, spring seats, diaphragm and pivot
(see illustration 14.21 ).
23 Remove any foreign material from the housing.
2 4 Installation is the reverse of removal. Make sure you install the
diaphragm so its vent hole is aligned with the vent holes in the throttle
body and housing.
25 After you have replaced the regulator and installed the throttle body
on the engine, start the engine and check for leaks.
26 Adjust the fuel pressure (see Section 3).
Throttle position sensor (TPS)
14.10 Gently grasp the center collar and carefully extract the
injector by rocking it back and forth while lifting up - do not
twist it during removal
Refer to illustration 14.28
27 Remove the upper and lower air inlet bonnets (see Section 12).
28 Remove the throttle body (see Section 13). This is not absolutely
necessary, but it makes it easier to get at the TPS. If you don't remove
the throttle body, unplug the TPS connector (see illustration). Note
THROTTLE
BODY
DIAPHRAGM
VENT HOLE
T
SPRING
MOUNTING
SCREWS
HOUSING
CONNECTOR
ARM
14.21
An exploded view of the fuel pressure
regulator assembly
1 4 . 2 8 To remove the throttle position sensor (TPS),
unplug the electrical connector and remove the two
mounting screws
J
4
The Motor Manual Guy
Chapter 4
4-16
Fuel and exhaust systems
15.4
14.33 Disconnect the ISA motor harness connector; t o
remove the motor, unscrew the three mounting nuts - use
a back-up wrench t o avoid damaging the motor
that the TPS used on vehicles w i t h automatic transmissions has t w o
connectors.
29 Remove the TPS mounting screws (see illustration 14.28).
3 0 Remove the TPS from the throttle shaft lever.
3 1 Installation is the reverse of removal. Be sure the TPS arm is underneath the throttle shaft lever.
3 2 Have the TPS adjusted by a dealer service department.
ldle speed stepper motor connector (left) - TPS
connector (right)
3 8 After you have replaced the ISA motor, have it adjusted by a dealer
service department.
15
Multi-Point Fuel Injection (MPI) - component replacement
Idle speed actuator (!SA) motor
Warning: Gasoline is extremely flammable, so extra precautions must
be taken when working on any part of the fuel system. Don't smoke
or allow open flames or bare light bulbs in or near the work area. Also,
don't work in a garage where a natural gas appliance such as a water
heater or clothes dryer is present.
Refer to illustration 14.33
3 3 Remove the ISA motor harness connector (see illustration).
3 4 Detach the throttle return spring (see illustration 13.6).
3 5 Remove the three ISA motor-to-bracket mounting nuts (see illustration 14.33). Use a back-up wrench t o prevent the studs which hold
the ISA motor together from turning. Caution: Don't attempt to remove
the ISA motor-to-bracket nuts without using a back-up wrench on the
stud nuts. ISA motor internal components may be damaged if the studs
disengage.
3 6 Remove the ISA motor from the bracket.
37 Installation is the reverse of removal.
Refer to illustrations 15.4, 15.5, 15.6 and 15.7
1 Detach the cable from the negative battery terminal.
2 Relieve the fuel pressure (see Section 2).
3 Disconnect the flexible air duct from the throttle body (see Section 7).
4 Detach the idle speed stepper motor and throttle position sensor
wire connectors (see illustration).
5 Detach the M A P sensor vacuum tube from the back of the throttle
body (see illustration).
6 Detach the throttle linkage at the throttle arm (see illustration).
15.5 Use a small screwdriver t o pry the MAP sensor
vacuum tube from the back of the throttle body
15.6 To detach the linkage from the throttle arm, insert a
screwdriver between the linkage and the arm and pop i t loose
Throttle body
The Motor Manual Guy
Chapter 4
Fuel and exhaust systems
4-17
TRANSMISSION
PRESSURE CABLE
15.7
If the vehicle is equipped with an automatic transmission,
detach the line pressure cable at the throttle arm
7 If equipped with an automatic transmission, detach the line pressure cable at the throttle arm (see illustration).
8 Remove the mounting bolts, throttle body and gasket. Discard the
old gasket and clean the gasket mating surfaces on the throttle body
and intake manifold.
9 Installation is the reverse of removal.
15.15 To remove the TPS, remove the retaining screws
(arrows), then pull the TPS from the throttle plate assembly
if
the screws are secured by lock tabs (as shown here), bend the
tabs back - use new tabs when reinstalling the screws
move the retaining screws, then detach the TPS from the throttle plate
assembly.
16 Installation is the reverse of removal. Be sure the slot on the TPS
aligns with the blade on the end of the throttle shaft.
17 Have the TPS adjusted by a dealer service department. Note: The
TPS on 1991 and later models in non-adjustable.
Idle speed stepper motor
Fuel injector rail assembly
10 Detach the cable from the negative battery terminal.
11 Unplug the wire connector from the idle speed stepper motor, remove the retaining screws, then pull off the idle speed stepper motor
(see illustration 15.4).
12 Installation is the reverse of removal.
Refer to illustrations 15.21a, 15.21 b, 15.23a, 15.23b, 15.23c, 15.24
and 15.27
18 Remove the fuel filler cap to relieve fuel tank pressure.
19 Relieve the fuel pressure (see Section 2).
20 Detach the cable from the negative battery terminal.
21 Numerically label, then unplug, the injector harness connectors
(see illustrations).
22 Detach the vacuum tube from the fuel pressure regulator (see illustration 3.36).
23 Detach the fuel supply hose from the fuel rail, the fuel return line
from the intake manifold, then the fuel return line from the fuel pressure
Throttle position sensor
Refer to illustration 15.15
13 Detach the cable from the negatrve battery terminal.
14 Unplug the TPS wire connector (see illustration 15.4).
15 Bend back the TPS lock tabs, if equipped (see illustration) Re-
15.21a Numerically label the injector harness connectors
(arrows) so you don't mix them up during reassembly
15.21 b Use a scribe (shown) or a small screwdriver to
pop loose the retaining clip that attaches the harness
connector to each injector
4
The Motor Manual Guy
Chapter 4
4-18
Fuel and exhaust systems
15.23a Detach the fuel supply hose from the fuel rail
15.23c
...
then detach the fuel return line from the fuel
pressure regulator
15.27 Before installing the fuel rail mounting bolts,
position the tip of each injector over its respective bore in
the intake manifold, then push down on the injectors to
seat them completely
15.23b Remove the nut from the fuel return line bracket
and slide the bracket off its mounting stud, . . .
15.24
Remove the fuel rail mounting bolts (arrows)
15.32 Use a small screwdriver (shown) or scribe to pop loose
the clip that secures the injector to the fuel rail assembly
The Motor Manual Guy
Chapter 4 Fuel and exhaust systems
15.33 Be sure to remove the old O-ring and seal from the
injector (a replacement kit, available at a dealer, includes six
enough O-rings and seals for all six
O-rings and seven seals
injectors and an extra seal for the fuel pressure regulator)
regulator (see illustrations). Refer t o Section 12 for information on
removing and replacing fuel line fittings.
2 4 Remove the fuel rail mounting bolts (see illustration).
25 If the vehicle is equipped with an automatic transmission, it may
be necessary to remove the automatic transmission line pressure cable
and bracket to remove the fuel rail assembly (see illustration 15.7).
26 Remove the fuel rail by simultaneously rocking and pulling up on
it until all injectors are out of the intake manifold. Work slowly and
carefully so you don't damage the assembly.
27 Installation is the reverse of removal, but be sure to do the
following:
a) Before attempting to reattach the fuel rail assembly mounting
bolts, position the tip of each injector above its corresponding
bore in the intake manifold (see illustration), then seat the injectors by pushing down on them. You must seat the injectors properly before you tighten the fuel rail mounting bolts.
b) When you reattach the fuel lines, be sure to use a new 0-ring,
spacer and retainer repair kit (see Section 12).
15.40
4-19
Remove the fuel pressure regulator retaining
screws (arrows)
4
15.41
Pull the fuel pressure regulator off the end of the
fuel rail
Fuel injector
Refer to illustrations 15.32 and 15.33
28 Remove the fuel filler cap to relieve fuel tank pressure.
29 Relieve the system fuel pressure (see Section 2).
3 0 Detach the cable from the negative battery terminal.
31 Remove the fuel injector rail assembly (see above).
32 Remove the retaining clip(s) that attach the injector(s) to the rail
assembly (see illustration).
3 3 If you are servicing a leaking injector, remove the old O-rings and
seals (see illustration).
3 4 An O-ring kit is available from a dealer parts department. This kit
consists of 6 brown and 7 black seals. The brown seals fit on the injector tips; the black seals fit on the rail end of the injectors. Do not
switch the brown and black O-rings - they're different in design and
composition. The extra black seal is for the fuel pressure regulator see Step 42.
3 5 Because the O-ring kit includes enough O-rings for all six injectors
(they're not available individually), it's a good idea to replace the upper
and lower O-rings on all injectors, even if only one or t w o are actually
leaking at the time you service them. Otherwise, you will probably find
yourself repeating this entire procedure down the road - to fix other
leaky injectors.
3 6 Installation is the reverse of removal. Be sure t o coat the injector
O-rings with a little fuel before installing the injectors.
Fuel pressure regulator
Refer to illustrations 15.40, 15.4 1 and 15.42
37 Remove the fuel filler cap t o relieve fuel tank pressure.
3 8 Relieve the system fuel pressure (see Section 2).
15.42
Always install a new O-ring on the pressure regulator
39 Detach the cable from the negative battery terminal.
4 0 Remove the fuel pressure regulator retaining screws (see illustration).
4 1 Pull the regulator off the fuel rail (see illustration).
42 Whenever you remove the fuel pressure regulator, always install
a new O-ring (see illustration). This O-ring is available as part of an
O-ring kit for the injectors (see Step 3 4 above).
43 Installation is the reverse of removal.
The Motor Manual Guy
4-20
Chapter 4
Fuel and exhaust systems
16.1a Exploded views of t w o typical
exhaust systems (four-cylinder models
above. V 6 models below)
1 Upstream air injection
tube (if equipped)
2 Downstream air injection
tube (if equipped)
3 Upper heat shield
4 Tail pipe
5 Muffler
6 Catalytic converter
7 Lower heat shield
8 Exhaust pipe
9 Oxygen sensor
1 6 Exhaust system servicing - general information
Refer to illustrations 16. l a and 16. Tb
Warning: Inspection and repair of exhaust system components should
be done only after enough time has elapsed after driving the vehicle
to allow the s vstem components to cool completely. Also, when working under the vehicle, make sure it is securely supported on jackstands.
1 The exhaust system (see illustration) consists of the exhaust
manifold(s), the catalytic converter, the muffler, the tailpipe and all
connecting pipes, brackets, hangers and clamps. The exhaust system
is attached t o the body with mounting brackets and rubber hangers
(see illustration). If any of the parts are improperly installed, excessive
noise and vibration will be transmitted to the body.
2 Conduct regular inspections of the exhaust system to keep it safe
and quiet. Look for any damaged or bent parts, open seams, holes,
loose connections, excessive corrosion or other defects which could
allow exhaust fumes to enter the vehicle. Deteriorated exhaust system
components should not be repaired; they should be replaced with new
parts.
3 If the exhaust system components are extremely corroded or rusted
together, welding equipment will probably be required to remove them.
The convenient way to accomplish this is to have a muffler repair shop
remove the corroded sections with a cutting torch. If, however, you
want to save money by doing it yourself (and you don't have a welding
outfit with a cutting torch), simply cut off the old components with
a hacksaw. If you have compressed air, special pneumatic cutting
chisels can also be used. If you do decide to tackle the job at home,
be sure to wear safety goggles t o protect your eyes from metal chips
and work gloves to protect your hands.
4 Here are some simple guidelines to follow when repairing the
exhaust system:
a) Work from the back to the front when removing exhaust system
components.
b) Apply penetrating oil to the exhaust system component fasteners
16. b Whenever you raise the vehicle for any reason, be
sure t o inspect the rubber exhaust hangers (arrow) for
deterioration - because they're subjected to heat and
vibration, the hangers frequently wear out and break
to make them easier to remove.
c) Use new gaskets, hangers and clamps when installing exhaust
systems components.
d) Apply anti-seize compound to the threads of all exhaust system
fasteners during reassembly.
e) Be sure t o allow sufficient clearance between newly installed
parts and all points on the underbody to avoid overheating the
floor pan and possibly damaging the interior carpet and insulation.
Pay particularly close attention to the catalytic converter and heat
shield.
The Motor Manual Guy
Chapter 5 Engine electrical systems
Contents
Alternator brushes - replacement ..................................................
18
Alternator - removal and installation ..............................................
17
4
Battery cables - check and replacement.......................................
Battery check and maintenance
See Chapter 1
2
Battery - emergency jump starting.................................................
Battery - removal and installation ..................................................
3
Centrifugal advance mechanism - check and
replacement (1984 and 1985 four-cylinder models only)...............
11
Charging system - check
16
Charging system - general information and precautions
15
Distributor cap and rotor check and replacement..
See Chapter 1
Distributor - removal and installation .............................................
13
Drivebelt check, adjustment and replacement
See Chapter 1
General information
1
7
Ignition coil - check and replacement............................................
Ignition control module - check and replacement
8
1
General information
The engine electrical systems include all ignition, charging and starting components. Because of their engine-related functions, these components are discussed separately from chassis electrical devices such
as the lights, the instruments, etc. (which are included in Chapter 12).
Always observe the following precautions when working on the electrical systems:
a) Be extremely careful when servicing engine electrical components. They are easily damaged if checked, connected or handled
improperly.
b) Never leave the ignition switch on for long periods of time with
the engine off.
c) Don't disconnect the battery cables while the engine is running.
d) Maintain correct polarity when connecting a battery cable from
another vehicle during jump starting.
e) Always disconnect the negative cable first and hook it up last
or the battery may be shorted by the tool being used to loosen
the cable clamps.
It's also a good idea to review the safety-related information regarding the engine electrical systems located in the Safety first section near
the front of this manual before beginning any operation included in this
Chapter.
2
lgnition pick-up coil (V6 engines only) - check
12
and replacement
6
Ignition system - check
5
Ignition system - general information.............................................
Ignition timing check and adjustment
See Chapter 1
Spark plug replacement .................................................. See Chapter 1
Spark plug wire check and replacement......................... See Chapter 1
21
Starter motor removal and installation
20
Starter motor - testing in vehicle
22
Starter solenoid - removal and installation.....................................
19
Starting system - general information and precautions
14
Stator - replacement (inline six-cylinder models only)
Trigger wheel and/or pickup coil assembly - removal and
9
installation (1984 and 1985 four-cylinder models only)
Vacuum advance mechanism check and replacement
10
(1984 and 1985 four-cylinder models only)
3
Battery - removal and installation
Refer to illustration 3.2
Caution: Always disconnect the negative cable first and hook it
up last or the battery may be shorted by the tool being used to loosen
the cable clamps. Disconnect both cables from the battery terminals.
2 Remove the battery hold down clamp (see illustration).
1
Battery - emergency jump starting
Refer to the Booster battery (jump) starting procedure at the front
of this manual.
3 . 2 Unscrew the nuts (1 ), remove the bolt (not visible in
this photo) and lift off the locator bracket (2), then pull the
hold down clamp (3) off the battery
5
The Motor Manual Guy
5-2
Chapter 5
Engine electrical systems
3 Lift out the battery. Be careful - it's heavy.
4 While the battery is out, inspect the carrier (tray) for corrosion (see
Chapter 1 ).
5 If you are replacing the battery, make sure that you get one that's
identical, with the same dimensions, amperage rating, cold cranking
rating, etc.
6 Installation is the reverse of removal.
4 Battery cables - check and replacement
1 Periodically inspect the entire length of each battery cable for
damage, cracked or burned insulation and corrosion. Poor battery cable
connections can cause starting problems and decreased engine performance.
2 Check the cable-to-terminal connections at the ends of the cables
for cracks, loose wire strands and corrosion. The presence of white,
fluffy deposits under the insulation at the cable terminal connection
is a sign that the cable is corroded and should be replaced. Check the
terminals for distortion, missing mounting bolts and corrosion.
3 When removing the cables, always disconnect the negative cable
first and hook i t up last or the battery may be shorted by the tool used
to loosen the cable clamps. Even if only the positive cable is being
replaced, be sure to disconnect the negative cable from the battery
first (see Chapter 1 for further information regarding battery cable
removal).
4 Disconnect the old cables from the battery, then trace each of them
to their opposite ends and detach them from the starter solendid and
ground terminals. Note the routing of each cable to ensure correct
installation.
5 If you are replacing either or both of the old cables, take them with
you when buying new cables. It is vitally important that you replace
the cables with identical parts. Cables have characteristics that make
them easy to identify: positive cables are usually red, larger in crosssection and have a larger diameter battery post clamp; ground cables
are usually black, smaller in cross-section and have a slightly smaller
diameter clamp for the negative post.
6 Clean the threads of the solenoid or ground connection with a wire
brush to remove rust and corrosion. Apply a light coat of battery terminal corrosion inhibitor, or petroleum jelly, to the threads to prevent
future corrosion.
7 Attach the cable to the solenoid or ground connection and tighten
the mounting nut/bolt securely.
8 Before connecting a new cable to the battery, make sure that it
reaches the battery post without having to be stretched.
9 Connect the positive cable first, followed by the negative cable.
5 lgnition system
-
general information
1984 and 1985 four-c ylinder engine
The Computerized Emission Control Solid State lgnition (CEC/SSI)
system used on 1984 and 1985 models with a four-cylinder engine
utilizes a microcomputer unit (MCU) t o monitor engine operating conditions. According to the operating conditions, the MCU advances or
retards ignition timing as necessary.
1986 and later four-c ylinder engine
1986, an ignition system designed for use with Throttle Body Injection (TBI) (which replaced the YFA carburetor that year) was installed
on vehicles with a four-cylinder engine. This system, which is used
on all 1986 and later four-cylinder vehicles, consists of a solid state
ignition control module (ICM), a conventional distributor and rotor
assembly, an Electronic Control Unit (ECU), a specially machined flywheel and a Top Dead Center (TDC) sensor.
The solid state ignition control module, which is located in the engine
compartment on the right side of the shock tower area, consists of
a solid state ignition circuit and an integrated ignition coil that can be
removed and serviced separately if necessary. The ICM controls ignition advance/retard electronically. Signals from the ECU to the ICM
determine the amount of ignition timing advance or retard needed t o
meet various engine load requirements.
The ECU gets its information regarding TDC, BDC and engine speed
from a TDC sensor mounted on the flywheel/driveplate housing. The
flywheel has t w o teeth machined off every 180° to define a precise
point 90° before TDC and BDC. The sensor is non-adjustable; it is preset
during engine assembly at the factory.
V6 engine
A High Energy lgnition (HE!) system with an externally mounted ignition coil is used on models with a V6 engine. There are t w o different
methods for controlling spark timing.
a) The 49-state system uses conventional centrifugal and vacuum
advance.
b) Spark timing is electronically controlled on California models by
means of a special distributor actuated by the electronic control
module (ECM). No vacuum or centrifugal advance is used.
fnline six-c ylinder engine
The ignition system used on inline six-cylinder models is similar in
design and function to the system used on 1986 and later four-cylinder
engines (see above).
6
lgnition system check
--
Warning: Because o f the very high voltage generated b y the ignition
system, extreme care should be taken when this check is performed.
1 If the engine turns over but won't start, disconnect the spark plug
wire from any spark plug and attach it t o a calibrated ignition tester
(available at most auto parts stores). Connect the clip on the tester to
a bolt or metal bracket on the engine. Make sure the tester is compatible with your ignition system if a universal tester isn't available. If
you're unable t o obtain a calibrated ignition tester, remove the wire
from one of the spark plugs and, using an insulated tool, hold the end
of the wire about 114-inch from a good ground.
2 Crank the engine and watch the end of the tester or spark plug
wire to see if bright blue, well-defined sparks occur. If you're not using
a calibrated tester, have an assistant crank the engine for you.
3 If sparks occur, sufficient voltage is reaching the plug to fire it (repeat the check at the remaining plug wires to verify that the distributor
cap and rotor are OK). However, the plugs themselves may be fouled,
so remove and check them as described in Chapter 1.
4 If no sparks or intermittent sparks occur, remove the distributor
cap and check the cap and rotor as described in Chapter 1. If moisture
is present, dry out the cap and rotor, then reinstall the cap and repeat
the spark test.
5 If there's still no spark, detach the coil secondary wire from the
distributor cap and hook it up to the tester (reattach the plug wire to
the spark plug), then repeat the spark check._Again, if you don't have a
tester, hold the end of the wire about 1/4-inch from a good ground,
using an insulated tool.
6 If sparks now occur, the distributor cap, rotor or plug wire(s) may
be defective.
7 If no sparks occur, the coil-to-cap wire may be bad (check the resistance with an ohmmeter - resistance should be approximately 250
to 1000 ohms per inch of wire). If a known good wire doesn't make any
difference in the test results, proceed to the next Step.
8 If there's still no spark, check the primary wire connections at the
coil to make sure they're clean and tight. Check for voltage to the coil.
Check the resistance of the coil also (see Section 7), comparing your
readings with the values listed in this Chapter's Specifications. Make
any necessary repairs, then repeat the check again.
9 If there's still no spark, the pick-up coil or ignition module may be
defective (see Sections 7 and 8).
7
lgnition coil
- check and replacement
Refer to illustrations 7.2a, 7.2b, 7.4, 7.5 and 7.8
Check
1 Detach the cable from the negative battery terminal.
2 Locate the ignition coil (see illustration). If you have difficulty finding the ignition coil, trace the lead from the center tower of the distributor cap back to the coil. You may find it easier to test the coil with
it removed. If so, follow the removal procedure below. If you do not
remove the coil, disconnect the wires from the high voltage and primary
The Motor Manual Guy
Chapter 5 Engine electrical systems
7.2a The ignition coil on four and inline six-cylinder models is
located on the right side of the engine compartment - when
removing the coil, unscrew the mounting bracket bolts (arrows)
terminals (see illustration).
3 Using an ohmmeter set on the high resistance scale, connect the
positive lead to the primary terminal and the negative lead t o ground
(see illustration 7.2b}. The ohmmeter should indicate infinite resistance.
If it doesn't, replace the coil.
4 Using the low resistance scale, connect the ohmmeter positive lead
to the positive primary terminal and the negative lead to the negative
terminal (seeillustration). The ohmmeter should indicate zero (or nearly
zero) resistance. If it doesn't, replace the coil.
5 Using the high resistance scale, connectthe ohmmeter negative
lead t o the negative primary terminal and the positive lead to the
high voltageterminal (see illustration}. The ohmmeter should not indicate infinite resistance. If it does, replace the coil.
5-3
7.2b Locations of the primary ( 1) and high voltage (2) coil
terminals - to check the coil, select the high resistance scale on
the ohmmeter, touch the positive lead to the coil positive terminal
and the negative lead to ground (the coil frame) - the indicated
resistance should be infinite
Replacement
6
Detach the cable from the negative battery terminal.
7 If you haven't already done so, detach the wires from the high
voltage and primary terminals of the coil (see illustration 7.2b}.
8 Detach the Ignition Control Module (ICM) wire connectors, if
equipped. (see illustration).
9 Remove the coil mounting bracket bolts (see illustration 7.2a)
and detach the coil.
10 Installation is the reverse of removal.
--
8
Ignition control module - check and replacement
Check
1
You need an approved ignition control module tester (Tester
7.5 Using the high resistance scale, touch the ohmmeter
negative lead t o the negative primary terminal and the
positive lead t o the high voltage terminal - t h e indicated
resistance should be less than infinite
7.4 Using the low resistance scale, touch the positive
lead to the positive primary coil terminal and the negative
lead to the negative terminal - the indicated resistance
should be zero or close to zero
J-24642E or equivalent) to test the ignition control modules used with
any of the vehicles covered by this manual. Without this equipment,
module testing is beyond the scope of the home mechanic. If you have
access t o the necessary tool, the instructions for testing the module
are provided by the manufacturer.
Replacement
Refer to illustration 8.4
V6 models
2 Detach the cable from the negative battery terminal.
3 Remove the distributor cap and rotor (see Chapter 1 ).
7.8
When removing the coil, detach the Ignition Control
Module (ICM) wire connectors (if equipped)
The Motor Manual Guy
Chapter 5
5-4
Engine electrical systems
If the distributor is not installed in the engine, support the shaft while
installing the trigger wheel pin.
1 4 lnstall the rotor and the distributor cap.
15 Attach the cable to the negative battery terminal.
10
Vacuum advance mechanism
check and
replacement (1984 and 1 9 8 5 four-cylinder models only)
Check
8.4
lgnition control module used on
1 Pickup coil assembly
2 Module attaching screws
models
3 Ignition control module
4 Pickup coil connector
4 Remove the t w o module attaching screws (see illustration) and
lift the module up.
5 Detach the pickup coil wire connector from the module (see illustration 8.41. Note the wire colors - the connectors must not be interchanged.
6 Disconnect the wire harness connector.
7 If you will be reinstalling the old module, don't wipe the grease
from the module or the distributor base. If you install a new module,
a package of silicone dielectric compound will be included with it.
Spread the compound on the metal face of the module and on the
distributor base where the module seats. This compound is necessary
for module insulation and cooling.
8 lnstallation is the reverse of removal.
1 Hook up a timing light in accordance with the manufacturer's
instructions.
2 Make sure the vacuum hose is attached to the vacuum advance
mechanism (see illustration 9.5).
3 Run the engine until it reaches normal operating temperature.
4 With the engine idling, watch the timing marks at the front of the
engine with the timing light (see Chapter 1 for more information). Note:
The white paint mark on the timing degree scale identifies the specified
timing degrees Before Top Dead Center (BTDC} at 1600 rprn; it does
not identify TDC.
5 Slowly increase the engine speed to 2000 rpm, noticing how
quickly the ignition timing advances. Disconnect and plug the vacuum
hose from the vacuum advance mechanism. Again, increase the engine
speed to 2000 RPM and notice how quickly the ignition timing advances.
With the hose connected, the ignition timing should advance more
quickly than it does with the hose disconnected. If it doesn't, replace
the vacuum advance mechanism. Note: A defective Micro Computer
Unit (MCU} can also alter ignition timing.
6 Unplug and reconnect the hose to the vacuum advance mechanism.
13
lnline six-cylinder models
9 Remove the ignition coil (see Section 7).
10 Remove the t w o screws that attach the module to the coil frame.
Pull off the module.
11 lnstallation is the reverse of removal.
-
9
-
Trigger wheel and/or pickup coil assembly - removal and
installation (1984 and 1985 four-cylinder models only)
Refer to illustration 9.5
Removal
~12
1 Detach the cable from the negative battery terminal.
2 The following procedure may be easier if you remove the distributor (see Section 13) but it's not absolutely necessary that you do so.
3 If you do decide to remove the distributor, place it in a bench vise.
4 Remove the distributor cap and rotor (see Chapter 1).
5 Using the trigger wheel puller tool (J-28509 or equivalent), remove
the trigger wheel (see illustration). Use a flat washer to prevent the
puller from contacting the inner shaft. Remove the pin.
6 Remove the pickup coil assembly retainer and washers from the
pivot pin on the base plate.
7 Remove the two pickup coil plate screws.
8 Lift the pickup coil assembly from the distributor housing.
~
11
10
Installation
9
Position the pickup coil assembly into the distributor housing.
1 0 Make sure the pin on the pickup coil assembly fits into the hole
in the vacuum advance mechanism link.
1 1 Install the washers and retainer on the pivot pin to secure the pickup
coil assembly to the base plate.
12 Position the wiring harness in the slot in the distributor housing.
lnstall the t w o pickup coil plate screws and tighten them securely.
13 Install the trigger wheel on the shaft with hand pressure. The long
portion of the teeth must face up. When the trigger wheel and slot
in the shaft are properly aligned, use a pin punch and a small hammer
to tap the pin into the locating groove in the trigger wheel and shaft.
9.5
Exploded view of the distributor assembly used on
1 9 8 4 and 1985 four-cylinder engines
Pin
2 Gear
3 Washer
4 Distributor body
5 Vacuum advance
mechanism
6 Wick
7
8
9
10
Washers
Pickup coil
Pickup coil retainer
Trigger wheel
11 Pin
12 Rotor
13 Cap
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-5
12.3 Before removing the pick-up coil, unplug the lead from the
ignition module
12.4 Ohmmeter connections for checking the pick-up coil on a
typical V6
Replacement
7 Detach the cable from the negative battery terminal.
8 Remove the distributor cap and rotor (see Chapter 1).
9 The following procedure is easier if you remove the distributor (see
Section 13), but it's not absolutely necessary that you do so.
10 If you do decide to remove the distributor, place it in a bench vise.
11 Remove the pickup coil (see Section 9).
12 Remove the vacuum hose and attaching screws from the vacuum
advance mechanism (see illustration 9.5). Tilt the vacuum advance
mechanism to disengage the link from the pickup coil pin, which protrudes through the distributor housing. If necessary, loosen the base
plate screws to get more clearance. Lift the vacuum advance mechanism out of the distributor housing.
13 To calibrate a new vacuum advance mechanism:
a) Insert an appropriately sized Allen wrench into the vacuum hose
tube of the old vacuum advance mechanism; count the number
of clockwise turns necessary to bottom the adjusting screw.
b) Turn the adjusting screw of the replacement vacuum advance
mechanism clockwise to bottom it, then turn it counterclockwise
the same number of turns you counted above.
14 lnstall the advance mechanism on the distributor housing. Make
sure the link is engaged on the pin of the pickup coil.
15 lnstall and tighten the vacuum advance mechanism attaching
screws. If you loosened the base plate screws, tighten them too.
16 lnstall the pickup coil (see Section 9).
17 lnstall the distributor (see Section 13).
18 lnstall the distributor cap and rotor (see Chapter 1).
19 Attach the cable to the negative battery terminal.
20 Check the ignition timing and adjust it, if necessary (see Chapter 1).
21 Attach the vacuum hose to the vacuum advance mechanism.
11
-
Centrifugal advance mechanism check and replacement
(1984 and 1985 four-cylinder models only)
12
Ignition pick-up coil (V6 engines only) - check and
replacement
Refertoillustrations 12.3, 12.4, 12.9, 12.11a, 12.11b, 12.11c, 12.14a
and 12.14b
Check
1 Detach the cable from the negative terminal of the battery.
2 Remove the distributor cap and rotor (see Chapter 1).
3 Detach the pick-up coil leads from the module (see illustration).
4 Connect one lead of an ohmmeter to the terminal of the pick-up
coil lead and the other to ground as shown (see illustration). Flex the
leads by hand to check for intermittent opens. The ohmmeter should
indicate infinite resistance at all times. If it doesn't, the pick-up coil is
defective and must be replaced.
5 Connect the ohmmeter leads to both terminals of the pick-up coi
Flex the leads by hand to check for intermittent opens. The ohmmeter
should read one steady value between 500 and 1500 ohms as the
leads are flexed by hand. If it doesn't, the pick-up coil is defective and
must be replaced.
Replacement
6 Remove the distributor (see Section 13).
7 Remove the two rotor mounting screws and remove the rotor.
8 Disconnect the pick-up coil leads from the module.
9 On models with a Hall-effect switch, remove the switch retaining
screws and the switch (see illustration).
PICKUP
ASSEMBLY
MODULE
1 Detach the vacuum hose from the vacuum advance mechanism
and plug it (see illustration 9.5).
2 Hook up a timing light and tachometer in accordance with the
manufacturer's instructions.
3 Start the engine and, with the engine idling, watch the timing
marks at the front of the engine with the timing light (see Chapter 1 for
more information).
4 Slowly increase engine speed t o 2000 rpm. Timing should advance smoothly as engine speed increases. If it advances unevenly,
the centrifugal advance mechanism is faulty. Replace the distributor
(see Section 12). You will need to switch the following parts to the replacement distributor:
a) Cap and rotor (see Chapter 1).
b) Trigger wheel and/or pickup coil assembly (see Section 9).
c) Vacuum advance mechanism (see Section 10).
L L EFFECT SWITCH
IGNITION
CONNECTOR
TERMINALS
LATCH
"P"
TERMINAL
CONNECTOR
CKUP COIL LEADS
DISCONNECTED
FROM MODULE
12.9 Distributor details (V6 engines)
5
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-6
12.11a Mount the distributor shaft in a soft-jawed vise and, using
a drift punch and hammer, knock out the roll pin
12.1 1b Remove the driven gear and spacer washers from the end
of the shaft, making sure to note the order in which you remove
any spacers
12.11c Remove the shaft from the distributor
12.14a To remove the pick-up coil from a V6 engine distributor,
remove the retaining clip
10 Mark the distributor gear and shaft so they can be reassembled in
the same position.
11 Carefully mount the distributor in a soft-jawed vise and, using a
hammer and punch, remove the roll pin from the distributor shaft and
gear (see illustrations).
12 Remove the gear and washers from the shaft.
13 Carefully pull the shaft out through the top of the distributor.
14 Remove the "C" washer retaining ring at the center of the distributor (see illustration) and remove the pick-up coil (see illustration).
15 Installation is the reverse of the removal procedure. Be sure to use
a new roll pin when installing the.drive gear on the shaft.
ANCHOR HOLE FOR
PICKUP COIL ASSEMBLY
13 Distributor - removal and installation
Refer to illustrations 13.6, 13.1Oa, 13. 10b, 13.1Oc, 13.12a, 13.12b and
13.12c
Removal
1
2
Detach the cable from the negative battery terminal.
Detach the primary lead from the coil.
3 Disconnect all wires from the distributor. If the wires don't unplug
at the distributor, follow the wires as they exit the distributor to find the
connector.
4 Look for a raised "1" on the distributor cap. This marks the location for the number one cylinder spark plug wire terminal. If the cap
-
12.14b View of the distributor with the pick-up coil removed
when installing the pick-up coil make sure it engages with the
anchor plate
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-7
FRONT FACE OF
ENGINE BLOCK
j
OIL PUMP
GEAR SLOT
13.10a To seat the distributor on a four-cylinder engine, use a
screwdriver to rotate the oil pump gear so the slot is slightly past
the three o'clock position,
. ..
13.6 Before loosening the distributor hold-down bolt, make a
mark on the edge of the distributor base directly below, and in
line with, the rotor tip (1), then mark the distributor base and the
engine block (2) to ensure that the distributor is installed correctly
does not have a mark for the number one terminal, locate the number
one spark plug and trace the wire back to its corresponding terminal
on the cap.
5 Remove the distributor cap (see Chapter 1) and turn the engine
over until the rotor is pointing toward the number one spark plug terminal (see locating TDC procedure in Chapter 2).
6 Make a mark on the edge of the distributor base directly below the
rotor tip and in line with it (if the rotor on your engine has more than
one tip, use the center one for reference). Also, mark the distributor
base and the engine block to ensure that the distributor is installed
correctly (see illustration).
7 Remove the distributor hold down bolt and clamp, then pull the
distributor straight up to remove it. Caution: DO NOT turn the
crankshaft while the distributor is out of the engine, or the alignment
marks will be useless.
FRONT FACE OF
ENGINE BLOCK
5 O'CLOCK
APPROX.
ROTOR
PRE-POSITIONED
.
13.10b . . then, with the distributor cap removed, install the
distributor with the rotor pointing toward the five o'clock position
Installation
Note: If the crankshaft has been moved while the distributor is out, the
number one piston must be repositioned at TDC. This can be done by
feeling for compression pressure at the number one plug hole as the
crankshaft is turned. Once compression is felt, align the ignition timing
zero mark with the pointer.
8 Insert the distributor into the engine in exactly the same relationship to the block that it was in when removed.
9 To mesh the helical gears on the camshaft and the distributor, it
may be necessary to turn the rotor slightly. Recheck the alignment
marks between the distributor base and the block to verify that the
distributor is in the same position it was in before removal. Also check
the rotor to see if it's aligned with the mark you made on the edge of
the distributor base.
Seating the distributor
If you have difficulty seating the distributor on the engine block,
use the appropriate Step (10, 11 or 12 below) for the type of engine
you have. If the distributor seats properly, with the flange flush with the
engine block, proceed to Step 13.
10 If you have difficulty getting the distributor to seat properly on a
four-cylinder engine, use the following procedure:
a) Make sure the number one piston is at TDC (see Chapter 2).
b) Look into the hole in the engine block where the distributor
mounts. You should see the oil pump gear slot (see illustration).
Put a screwdriver into the slot and rotate the oil pump gear so the
gear slot is slightly past the three o'clock position.
c) With the distributor cap removed, install the distributor with the
rotor pointing to the five o'clock position (see illustration).
d) With the distributor fully engaged in its correct location, the rotor
should be pointing to the six o'clock position (see illustration).
e) If the distributor is still not installed correctly, repeat this procedure.
11 If you have difficulty getting the distributor to seat properly on a V6
engine, use the following procedure:
I
FRONT FACE OF
ENGINE BLOCK
I
\
ROTOR POSITION WHEN
PROPERLY INSTALLED
13.10c When the four-cylinder distributor is completely and
correctly seated (engaged), the rotor should be at the six
o'clock position
a) Remove the number one spark plug.
b) Place your finger over the number one spark plug hole and rotate
the crankshaft slowly until you feel compression.
c) Align the timing index mark on the vibration damper with 0-degree (TDC) on the graduated timing degree scale on the timing
gear cover.
d) Turn the rotor to point between the number one and number two
spark plug terminals on the distributor cap.
e) Install the distributor.
12 If you have difficulty getting the distributor to seat properly on an
inline six-cylinder engine, use the following procedure:
5
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-8
FRONT
OF
ENGINE
11 O'CLOCK
HOLD-DOWN
EAR
OIL
PUM P
GEAR SHAFT
13.12a To seat the distributor on an inline six-cylinder engine, use
a screwdriver to turn the oil pump gear shaft until the slot is
slightly past the 11 o'clock position, . .
.
FRONT
CLAMP BOLT HOLE
13.12b
13.12c
..
. visually line up the hold-down ear of the distributor
housing with the hold-down clamp bolt hole,
. ..
. . . turn the rotor to the four o'clock position, then slide
the distributor down into the block until it seats
a) Look into the hole in the engine block where the distributor
mounts. You should see the oil pump gear shaft (see illustration). Put a screwdriver into the slot in the oil pump gear shaft
and rotate the shaft until the slot is slightly past the 11 o'clock
position.
b) If you removed it, Install the rotor.
c) Without engaging the distributor gear with the camshaft gear in
the engine, position the distributor in the hole in the engine block.
Be sure the distributor gasket is installed.
d) Visually line up the hold-down ear of the distributor housing with
the hold-down clamp bolt hole (see illustration).
e) Turn the rotor to the four o'clock position (see illustration).
t) Slide the distributor down into the engine block until it seats.
Keep the hold-down ear aligned to the hole in the block.
g) The rotor should be in the five o'clock position with the trailing
edge of the rotor blade lined up with the mark you scribed on the
distributor housing prior to removal (the number one swark
. .oluawire post location):
h) If the distributor still won't seat properly, repeat this procedure.
13' Place the hold down clamp in position and loosely install the bolt.
14 Install the distributor cap.
15 Attach the electrical wires to the distributor.
16 Reattach the spark plug wires to the plugs (if removed).
17 Connect the cable to the negative terminal of the battery.
18 Check the ignition timing (see Chapter I) and tighten the distributor hold down bolt securely.
14.4 Use a small punch and hammer to drive out the retaining
pin, then remove the distributor gear from the shaft
14
-
Stator replacement (inline six-cylinder models only)
Refer to illustrations 14.4 and 14.6
1 Remove the distributor from the engine (see Section 13).
2 Remove the distributor cap and rotor (see Chapter 1).
3 Secure the distributor shaft gear in a bench vise. Wrap a rag
around the shaft to prevent damage from the vise jaws.
4 Use a small punch and hammer to drive out the retaining pin, then
remove the distributor gear from the shaft (see illustration).
5 Remove the distributor shaft from the distributor housing.
6 Mark the location of the stator (see illustration) so you can return
it to the same location during reassembly.
7 Remove the stator retaining screw (see illustration 14.6).
8 Remove the stator harness (see illustration 14.6) by pushing the
grommet through the distributor housing. Remove the stator assembly.
9 Installation is the reverse of removal.
The Motor Manual Guy
Chapter 5 Engine electrical systems
STATOR-HARNESS
5-9
GROMMET
STATOR RETAINING SCREW
14.6 After marking the position of the stator assembly with paint
or a scribe, remove the retaining screw, push the grommet
through the distributor housing and remove the stator
15
-
Charging system general information and precautions
The charging system includes the alternator, an internal voltage
regulator, a charge indicator, the battery, a fusible link and the wiring
between all the components. The charging system supplies electrical
power for the ignition system, the lights, the radio, etc. The alternator
is driven by a drivebelt at the front of the engine.
The purpose of the voltage regulator is to limit the alternator's voltage to a preset value. This prevents power surges, circuit overloads,
etc., during peak voltage output.
The fusible link is a short length of insulated wire integral with the
engine compartment wiring harness. The link is four wire gauges
smaller in diameter than the circuit it protects. Production fusible links
and their identification flags are identified by the flag color. See Chapter 12 for additional information regarding fusible links.
The charging system doesn't ordinarily require periodic maintenance. However, the drivebelt, battery, battery cables and connections
should be inspected at the intervals outlined in Chapter 1.
The dashboard warning light should come on when the ignition
key is turned to Start, then go off immediately. If it remains on, there is
a malfunction in the charging system (see Section 16). Some vehicles
are also equipped with a voltmeter. If the voltmeter indicates abnormally high or low voltage, check the charging system (see Section 16).
Be very careful when making electrical circuit connections to a vehicle equipped with an alternator and note the followinq:
a) When reconnecting wires to the alternator from-the battery, be
sure to note the polarity.
b) Before using arc welding equipment to repair any part of the vehicle, disconnect the wires from the alternator and the battery terminals.
c) Never start the engine with a battery charger connected.
d) Always disconnect both battery leads before using a battery
charger.
e) The alternator is turned by an engine drivebelt which could cause
serious injury if your hands, hair or clothes become entangled in it
with the engine running.
f) Because the alternator is connected directly to the battery, it
could arc or cause a fire if overloaded or shorted out.
g) Wrap a plastic bag over the alternator and secure it with rubber
bands before steam cleaning the engine.
16
16.5 To test the alternator, locate the test hole in the back,
ground the tab that's located inside the hole by inserting a
screwdriver blade into the hole and touching the tab and the case
at the same time
Charging system - check
Refer to illustration 16.5
1 If a malfunction occurs in the charging circuit, don't automatically
assume that the alternator is causing the problem. First check the fol-
lowing items:
a) Check the drivebelt tension and condition (Chapter 1). Replace it
if it's worn or deteriorated.
b) Make sure the alternator mounting and adjustment bolts are tight.
c) Inspect the alternator wiring harness and the connectors at the
alternator and voltage regulator. They must be in good condition
and tight.
d) Check the fusible link (if equipped) located between the starter
solenoid and the alternator. If it's burned, determine the cause,
repair the circuit and replace the link (the vehicle won't s tart
and/or the accessories won't work if the fusible link blows-).
Sometimes a fusible link may look good, but still be bad. I fin
doubt, remove it and check for continuity with an ohmmeter or
test light.
e) Start the engine and check the alternator for abnormal noises (a
shrieking or squealing sound indicates a bad bearing).
9 Check the specific gravity of the battery electrolyte. If it's low,
charge the battery (doesn't apply to maintenance free batteries).
g) Make sure the battery is fully charged (one bad cell in a battery
can cause overcharging by the alternator).
h) Disconnect the battery cables (negative first, then positive). Inspect the battery posts and the cable clamps for corrosion. Clean
them thoroughly if necessary (see Chapter 1). Reconnect the cable to the positive terminal.
i) With the key off, connect a test light between the negative battery
post and the disconnected negative cable clamp.
1) If the test light does not come on, reattach the clamp and proceed to the next step.
2) If the test light comes on, there is a short (drain) in the electrical system of the vehicle. The short must be repaired before
the charging system can be checked.
3) Disconnect the alternator wiring harness.
(a) If the light goes out, the alternator is bad.
(b) If the light stays on, pull each fuse until the light goes out
(this will tell you which component is shorted).
2 Using a voltmeter, check the battery voltage with the engine off. If
should be approximately 12-volts.
3 Start the engine and check the battery voltage again. It should
now be approximately 14-to-15 volts.
4 Locate the test hole in the back of the alternator. Note: If there is
no test hole, the vehicle is equipped with a newer CS type alternator.
Further testing of this type of alternator must be done by a dealer service department or automotive electrical shop.
5 Ground the tab that is located inside the hole by inserting a Screwdriver blade into the hole and touching the tab and the case at the
same time (see illustration). Caution: Do not run the engine with the
5
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-10
17.2 To remove the alternator, detach the electrical connectors
(arrows) from below, .
17.3a
..
17.3b
. . . and remove the alternator pivot bolt (arrow) from below
tab grounded any longer than necessary to obtain a voltmeter reading.
If the alternator is charging, i t is running unregulated during the test.
This condition may overload the electrical system and cause damage
to the components.
6 The reading on the voltmeter should be 15 volts or higher with the
tab in the test hole grounded.
7 If the voltmeter indicates low battery voltage, the alternator is
faulty and should be replaced with a new one (see Section 17).
8 If the voltage reading is 15 volts or higher and a no charge condition is present, the regulator or field circuit is the problem. Remove the
alternator (see Section 17) and have it checked further by an auto electric shop.
17
Alternator - removal and installation
Refer to illustrations 17.2, 17.3a and 17.3b
1 Detach the cable from the negative terminal of the battery.
2 Detach the electrical connectors from the alternator (see illustration).
3 Loosen the alternator adjustment and pivot bolts and detach the
drivebelt (see illustrations).
4 Remove the adjustment and pivot bolts and separate the alternator from the engine.
5 If you are replacing the alternator, take the old one with you when
purchasing a replacement unit. Make sure the new/rebuilt unit looks
identical to the old alternator. Look at the terminals - they should be
the same in number, size and location as the terminals on the old alter-
. . . loosen the alternator adjustment bolt (arrow).
18.2 Mark the drive end frame and rectifier end frame assemblies
with a scribe or paint before separating the two halves
nator. Finally, look at the identification numbers they will be stamped
into the housing or printed on a tag attached to the housing. Make
sure the numbers are the same on both alternators.
6 Many new/rebuilt alternators DO NOT have a pulley installed, so
you may have to switch the pulley from the old unit to the new/rebuilt
one. When buying an alternator, find out the shop's policy regarding
pulleys - some shops will perform this service free of charge.
7 Installation is the reverse of removal.
8 After the alternator is installed, adjust the drivebelt tension (see
Chapter 1).
9 Check the charging voltage to verify proper operation of the alternator (see Section 16).
18
Alternator brushes - replacement
Refer to illustrations 18.2, 18.3a, 18.3b, 18.4, 18.5, 18.6, 18.7and 18.10
Note: The following procedure applies only to SI type alternators. CS
types have riveted housings and cannot be disassembled.
1
Remove the alternator from the vehicle (Section 15).
2
Scribe or paint marks on the front and rear end frame housings of
the alternator to facilitate reassembly (see illustration).
3
Remove the four through-bolts holding the front and rear end
frames together, then separate the drive end frame from the rectifier
end frame (see illustrations).
4
Remove the nuts holding the stator to the rear end frame and
separate the stator from the end frame (see illustration).
The Motor Manual Guy
Chapter 5 Engine electrical systems
18.3a With the through bolts removed, carefully separate the
drive end frame and the rectifier end frame
5-1 1
18.3b Inside a typical Sl alternator
A
B
C
Brush holder
Paper clip retaining
brushes (for reassembly)
Regulator
D
E
F
Resistor (not all models)
Diode trio
Rectifier bridge
18.4 After removing the nuts holding the stator assembly to the
end frame, remove the stator
18.5 Remove the nuts attaching the diode trio to the rectifier
bridge and remove the trio
~===---------..
•
18.6 After removing the screws that attach the regulator and the
resistor (if equipped) to the end frame, remove the brush holder
5 Remove the nuts attaching the diode trio to the rectifier bridge
and remove the trio (see illustration).
6
Remove the screws attaching the resistor (not used on all models), regulator and brush holder to the end frame and remove the brush
holder (see illustration).
18.7 Slip the brush retainer off the brush holder and remove the
brushes (arrow)
Remove the brushes from the brush holder by slipping the brush
7
retainer off the brush holder (see illustration).
Remove the springs from the brush holder.
8
Installation is the reverse of the removal procedure, noting the fol9
lowing:
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-12
18.10 To hold the brushes in place during reassembly, insert
a paper clip through the hole in the end frame nearest to the
rotor shaft
21.3 Before unbolting the starter motor assembly, detach the
wires (arrows) from the solenoid (or from the starter motor itself
on some models) - be sure the battery is disconnected!
10 When installing the brushes in the brush holder, install the brush
closest to the end frame first. Slip the paper clip through the rear of
the end frame to hold the brush, then insert the second brush and
push the paper clip in to hold both brushes while reassembly is completed (see illustration). The paper clip should not be removed until
the front and rear end frames have been bolted together.
turned to Start, make sure the shift lever is in Neutral or Park (automatic transmission).
2 Make sure that the battery is charged and that all cables, both at
the battery and starter solenoid terminals, are clean and secure.
3 If the starter motor spins but the engine is not cranking, the overrunning clutch in the starter motor is slipping and the starter motor
must be replaced.
4 If, when the switch is actuated, the starter motor does not operate
at all but the solenoid clicks, then the problem lies with either the battery, the starter relay (if equipped), the main solenoid contacts or the
starter motor itself (or the engine is seized).
5 If the solenoid plunger cannot be heard when the switch is actuated, the battery is bad, the fusible link is burned (the circuit is open) or
the solenoid itself is defective.
6 To check the solenoid, connect a jumper lead between the battery
(+) and the ignition switch wire terminal (the small terminal) on the
solenoid. If the starter motor now operates, the solenoid is OK and the
problem is in the ignition switch, neutral start switch or the wiring.
7 If the starter motor still does not operate, remove the
starter/solenoid assembly for disassembly, testing and repair.
8 If the starter motor cranks the engine at an abnormally slow speed,
first make sure that the battery is charged and that all terminal connections are tight. If the engine is partially seized, or has the wrong viscosity oil in it, it will crank slowly.
9 Run the engine until normal operating temperature is reached,
then disconnect the coil wire from the distributor cap and ground it on
the engine.
10 Connect a voltmeter positive lead to the positive battery post and
connect the negative lead to the negative post.
11 Crank the engine and take the voltmeter readings as soon as a
steady figure is indicated. Do not allow the starter motor to turn for
more than 15 seconds at a time. A reading of 9 volts or more, with the
starter motor turning at normal cranking speed, is normal. If the reading is 9 volts or more but the cranking speed is slow, the motor is
faulty. If the reading is less than 9 volts and the cranking speed is
slow, the solenoid contacts are probably burned, the starter motor is
bad, the battery is discharged or there is a bad connection.
19
Starting system - general information and precautions
The sole function of the starting system is to turn over the engine
quickly enough to allow it to start.
The starting system consists of the battery, the starter motor, the
starter solenoid, a remote starter relay (on some models) and the wires
connecting them. A number of different starter motors - including
Bosch, Delco, Mitsubishi and Motorcraft - are used on the vehicles
covered by this manual. If you replace the starter motor, be sure to
take the old starter with you to the parts department to make sure you
get the right replacement. The solenoid is mounted directly on the
starter motor or, on Motorcraft units, is a separate component located
in the engine compartment.
The solenoid/starter motor assembly is installed on the lower part
of the engine, next to the transmission bellhousing.
When the ignition key is turned to the Start position, the starter
solenoid is actuated through the starter control circuit. The starter
solenoid then connects the battery to the starter. The battery supplies
the electrical energy to the starter motor, which does the actual work
of cranking the engine.
The starter on a vehicle equipped with an automatic transmission
can only be operated when the transmission selector lever is in Park or
Neutral.
Always observe the following precautions when working on the
startina svstem:
a) Excessive cranking of the starter motor can overheat it and cause
serious damage. Never operate the starter motor for more than
15 seconds at a time without pausing to allow it to cool for at
least two minutes.
b) The starter is connected directly to the battery and could arc or
cause a fire if mishandled, overloaded or shorted out.
c) Always detach the cable from the negative terminal of the battery
before working on the starting system.
20
-
Starter motor testing in vehicle
Note: Before diagnosing starter problems, make sure the battery is
fully charged.
1 If the starter motor does not operate at all when the switch is
21
Starter motor - removal and installation
Refer to illustrations 21.3, 21.4a and 21.4b
Note: On some vehicles, i t may be necessary to remove the exhaust
pipe(s) or frame crossmember to gain access to the starter motor. In
extreme cases it may even be necessary to unbolt the mounts and
raise the engine slightly to get the starter out.
1 Detach the cable from the negative terminal of the battery.
2 Raise the vehicle and support it securely on jackstands.
The Motor Manual Guy
Chapter 5 Engine electrical systems
5-13
21.4a Lower starter mounting bolt (inline six-cylinder model
21.4b Upper starter mounting bolt (inline six-cylinder model
shown) view is from the rear, looking forward
shown) view is from the front, looking to the rear
22.3 Before removing the solenoid from the starter motor, detach
the starter motor terminal strap (arrow) - Mitsubishi starter shown
22.4 To detach the solenoid from the starter motor, remove the
solenoid attaching screws (arrows) from the front of the starter's
solenoid mount (Mitsubishi starter shown) - the screws on Delco
starters are removed from the rear of the mount
-
3
Clearly label, then disconnect the wires from the terminals on the
starter motor and solenoid (if mounted on the starter) (see illustration).
4 Remove the mounting bolts (see illustrations)and detach the
starter.
5 Installation is the reverse of removal.
22
1
Starter solenoid - removal and installation
Disconnect the cable from the negative terminal of the battery.
AN solenoids except Motorcraft
Refer to illustrations 22.3, 22.4 and 22.5
2 Remove the starter motor (see Section 21).
3 Disconnect the strap from the solenoid to the starter motor terminal (see illustration).
4 Remove the screws which secure the solenoid to the starter motor
(see ..illustration).
5 On some models, twist the solenoid in a clockwise direction to disengage the flange from the starter body (see illustration).
6 Installation is the reverse of removal.
22.5 Some solenoids, like this Delco unit, must be rotated
clockwise before they can be disengaged from the starter motor
The Motor Manual Guy
5-14
Chapter 5 Engine electrical systems
Motorcraft solenoid
Refer to illustration 22.7
7 Locate the solenoid - it's mounted in the engine compartment near
the battery (see illustration). Detach the electrical wires from the
starter solenoid terminals. Label them to assure proper reassembly.
8 Remove the solenoid mounting bracket bolts and detach the
solenoid.
9 Installation is the reverse of removal.
22.7 If you have a Motorcraft starter solenoid, it's located near
the battery to remove it, detach the wires and remove the
mounting bracket bolts - be sure the battery is disconnected!
-
The Motor Manual Guy
Chapter 6
Emissions and engine control systems
Contents
Air filter and PCV filter replacement
See Chapter I
Air injection systems ......................................................................
5
Catalytic converter .........................................................................
7
Computer Command Control System (CCCS) and trouble codes
8
(V6 models) - description and trouble code retrieving
Emission Maintenance Timer
See Chapter 1, Section 46
Evaporative emissions control system check
See Chapter
Exhaust Gas Recirculation (EGR) system
6
Exhaust Gas Recirculation (EGR) system check
See Chapter 1
Fuel evaporative control system ....................................................
3
General information
1
Information sensors (1991 and later models)
11
9
Information sensors (V6 models)
-
-
I General information
Refer to illustrations 1.7, 1.Ba, 1.Bb, 1. Be, 1.Bd, 1.Be, 1.Bf, 1.Bg,
1.Bh and 1.Bi
To prevent pollution of the atmosphere from incompletely burned
and evaporating gases, and to maintain good driveability and fuel
economy, a number of emission control systems are incorporated. They
include the:
Computerized Emission Control (CECJ system
Exhaust Gas Recirculation (EGRJ system
Air injection system
Fuel evaporative emission control system
Positive Crankcase Ventilation (PCV) system
Thermostatic Air Cleaner (TAC) system
Catalytic converter
Oxygen sensor and emissions maintenance
timer replacement ...................................................... See Chapter 1
Positive Crankcase Ventilation (PCV) valve or Crankcase Ventilation
(CCV) hose check, cleaning and replacement ........... See Chapter 1
2
Positive Crankcase Ventilation (PCV) system ................................
Self-diagnosis codes (1991 and later models) - description and
trouble code retrieving .............................................................. 10
Spark plug replacement .................................................. See Chapter
Spark plug wire check and replacement ......................... See Chapter 1
Thermostatic Air Cleaner (TAC) (carburetor and
TBI-equipped vehicles).............................................................
4
Thermostatic air cleaner check ....................................... See Chapter 1
All of these systems are linked, directly or indirectly, to the emission control system.
The Sections in this Chapter include general descriptions, checking
procedures within the scope of the home mechanic and component
replacement procedures (when possible) for each of the systems listed
above.
Before assuming that an emissions control system is malfunctioning, check the fuel and ignition systems carefully. The diagnosis of
some emission control devices requires specialized tools, equipment
and training. If checking and servicing become too difficult or if a procedure is beyond your ability, consult a dealer service department.
Remember, the most frequent cause of emissions problems is simply
a loose or broken vacuum hose or wire, so always check the hose and
wiring connections first.
This doesn't mean, however, that emission control systems are Particularly difficult to maintain and repair. You can quickly and easily perform many checks and do most of the regular maintenance at home
6
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
6-2
with common tune-up and hand tools. Note: Because of a Federally
mandated extended warranty which covers the emission control system
components land any components which have a primary purpose other
than emissions control but have significant effects on emissions), check
with your dealer about warranty coverage before working on any
emissions-related systems. Once the warranty has expired, you may
wish t o perform some of the component checks and/or replacement
procedures in this Chapter t o save money.
Pay close attention to any special precautions outlined in this Chapter.
It should be noted that the illustrations of the various systems may not
exactly match the system installed on your vehicle because of changes
made by the manufacturer during production or from year-to-year.
A Vehicle Emissions Control lnforrnation label is located in the engine
compartment (see illustration).This label contains important emissions
specifications and adjustment information, as well as a vacuum hose
schematic with emissions components identified. When servicing the
engine or emissions systems, the VECI label in your particular vehicle
should always be checked for up-to-date information.
Later 49-state models ( 1 988 and 1989) are equipped with an emission maintenance timer and indicator light. The timer and light are there
to tell you when to replace the oxygen sensor and PCV valve and perform other emission maintenance. See Chapter 1 for more information about the emission maintenance timer. The accompanying emission control system schematics (see illustrations) can help you
troubleshoot the most common cause of emissions problems - loose,
detached or misrouted vacuum hoses.
1.7
The Vehicle Emission Control lnforrnation (VECI) label
contains tune-up specifications and vital information
regarding the location of all emission control devices and
the routing of all vacuum hoses
EVAPORATIVE
SYSTEM VACUUM
/
MOTOR
CARBURETOR
BOWL VENT
TO
FUEL TANK
I
-f'~;=;ii:~~~~+l
P.C.V. VALVE
--------"
P.C.V.
SOLENOID
Wi;ul/1 -
DENOTES COLOR ..fL
CODED SIDE '1.r
VACUUM
RESERVOIR
VACUUM
SWITCH
ASSEMBLY
IDLE/
DECELERATION
1.9a
Vacuum hose diagram for carburetor-equipped, 49-state four-cylinder models ( 1 9 8 4 and 1985)
The Motor Manual Guy
6-3
VAC R S V R
I
V A C U U M SWITCH ASSEMRLV
I
VAC RSVR
W CHK VLV
CARS BOWL VENT
TO F TNK
SOL
CANISTER
PCV SOL
PCV Ai9
OUT
1.9b Vacuum hose diagram
for carburetor-equipped, Canadian
four-cylinder models (1985)
DISTRIBUTOR
VAC RSVA
VACUUM SWITCH ASSEMBLY
VAC RSVR.
WCHK VLV
1.9c Vacuum hose diagram
for carburetor-ea_uiooed. California
four-cylinder models with manual
transmission (1985)
c
DISTRIBUTOR
The Motor Manual Guy
6-4---------------------------------TAC SENSOR
TO FUEL TANK
+
EGR CANISTER
SOLENOID
EGA VALVE
VACUUM MOTOR
MAP SENSOR
THROTTLE BODY
FRONT OF
VEHICLE
.
L _____ _
PCV AIR IN
I
031 RESTRICTOR
1.9d Vacuum hose diagram
for TBI-equipped four-cylinder
models (1 986)
O M RESTRICTOR
PCV'CANISTER PURGE
PURGE SIGNAL
i
MAP SENSOR
-t::::=:JI
TO FUEL TANK
r-DENOTES COLOR ..r.. VAPOR & AIR HOSES
CODED SIDE
'-1.:r
VACUUM HOSES~
R/DELAY VLV
I.
' '/
EGR VALVE
/
AIR CLEANER
NER
VACUUM MOTOR
Vacuum hose diagram
for TBI-equipped
four-cylinder models
(1987 on)
1.9e
.050 RESTRICTOR
FRONT OF
VEHICLE
The Motor Manual Guy
6-5
PURGE SIG
I
r.AN!STFR
-PURGE
CARS BOWL
VENT
SIG BOWL
VENT
CANISTER
CANISTER
VENT
~
~~-
DISTRIBUTOR
1.9f
Vacuum hose diagram for 49-state V6 models with manual transmission (1985 and 1986)
CANISTER
PURGE
CARBBOWI.
VENT
CANISTER
TO F TANK
NON LNR
VLV
o::(fl\l
'I
~
"
THROTTLE KICKER
RDELAY
DUAL CTO
DENOTES COLOR
CODEDSIDE
1.9g
,ffl-
Vacuum hose diagram for 49-state V 6 models with automatic transmission (1985 and 1986)
. :e:
The Motor Manual Guy
6-6
CANISTER
PURGE
CARB BOWL
VENT
VAC
RSVR
WCHK VLV
\
PCV A!A
OUT
CANISTER
\ CANISTER
VENT
EGA VALVE
SPARK CHECK
DUAL CTO
DISTRIBUTOR
'---.._,_
:
~-'--p~:-')
:\.<
J
--
AIAIN
,,
I
II .. .,___,,_ _ AIA CONTROL
)
VLV
1.9h
° ' A I R PUMP
1
.
Vacuum hose diagram for Canadian V 6 models (1985 and 1986)
=
& AIR HOSES
I!VAPOR
...
-......
··---- -1I
VACUUM
HOSES
M A P SENSOR
2 6 MM-==,,.,..-ORIFICE
VACUUM
~FITTING
THROTTLE
BODY
CANISTER
BI-METAL
TEMP
../C'C,..IC'r"\O
SENSOR
FRONT
OF
VEHICLE
YI:nl\...U:.
EGR SOLENOID
AIR CLEANER
PRESSURE
REG.
l
1.9i
VACUUM----+--iJa
MOTOR
Vacuum hose diagram for inline six-cylinder models
J
The Motor Manual Guy
6-7
Chapter 6 Emissions and engine control systems
2 Positive Crankcase Ventilation (PCV) system
Refer to illustrations 2.5a and 2.5b
1 The Positive Crankcase Ventilation (PCV) system reduces hydrocarbon emissions by scavenging crankcase vapors. It does this by circulating fresh air from the air cleaner through the crankcase, where
it mixes with blow-by gases and is then rerouted through a PCV valve
to the intake manifold.
2 The main components of the PCV system are the PCV valve, a
fresh air filtered inlet and the vacuum hoses connecting these two components with the engine.
3 To maintain idle quality, the PCV valve restricts the flow when
the intake manifold vacuum is high. If abnormal operating conditions
(such as piston ring problems) arise, the system is designed to allow
excessive amounts of blow-by gases to flow back through the
crankcase vent tube into the air cleaner to be consumed by normal
combustion.
4 Checking and replacement of the PCV valve and filter is covered
in Chapter 1.
5 Later fuel-injected vehicles are equipped with a Crankcase Ventilation System (see illustrations). The CCV system performs the same
function as a conventional PCV system but does not use a vacuum
controlled valve.
6 A molded vacuum tube connects manifold vacuum to a grommet
on the top rear of the rocker arm cover (four-cylinder engine) or top
front of the cover (inline six-cylinder engine). The grommet contains
a calibrated orifice that meters the amount of crankcase vapors drawn
out of the engine. A fresh air supply hose from the air cleaner is connected to the top front of the rocker arm cover (four-cylinder engine)
or the top rear of the cover (inline six-cylinder engine). When the engine
FROM AIR CLEANER
,
is operating, fresh air enters the engine and mixes with the crankcase
vapors. Manifold vacuum draws the vaporlair mixture through the
metered orifice and into the intake manifold. The vapors are consumed during combustion.
3 Fuel evaporative control system
Refer to illustrations 3.6a, 3.66, 3.6c and 3.6d
General description
1 The fuel evaporative control system prevents the release of unburned hydrocarbons
from liquid gasoline or fuel vapors - into the
atmosphere. When the pressure in the fuel tank exceeds 3 psi, a pressure relief/rollover valve opens, preventing excessive pressure build-up
in the tank and allowing the fuel vapors t o flow to an evaporative
canister, where they are absorbed by granules of an activated carbon
mixture.
2 When the vehicle is started, the fuel vapors stored in the canister
are drawn out of the canister and into the engine for combustion.
3 The evaporative canister inlet on fuel-injected vehicles is connected
to the fuel tank rolloveripressure relief valve(s) through a series of hoses
and tubes. The canister outlet is connected t o the air cleaner snorkel.
When the engine is operating, the canister purge valve draws fresh
air through the filter at the bottom of the canister, causing the stored
vapors t o be drawn from the canister and into the airstream in the air
cleaner snorkel.
4 A venturi in the air cleaner assembly creates a purge line vacuum
source. This venturi increases the speed of the intake air flowing by
the purge inlet slots in the venturi wall, which creates a low pressure
area at the inlet slots that draws vapors from the canister into the
.
2.5a Crankcase Ventilation (CCV) system used on
fuel-injected four-cylinder engines
I
I
I
I
I
I
I
I\
CCV AIR IN
.
CCV AIR OUT
j
I
FROM
INTAKE MANIFOLD
FITT···IN.G.
2.5b
:
Crankcase Ventilation (CCV) system used on
fuel-injected inline six-cylinder engines
CCV
!,
OUT
(I)
ft=•c::~·•··:c;:;i:•~·\•·•.••·•• . . . . .:. . . •·.
2.6 MM
ORIFICE
-
'
..·. ----,q\ .. \
,1 A,.~-
I
\
AIR CLEANER
. ·•· •
CCV AIR IN
I
)
The Motor Manual Guy
6-8
Chapter 6 Emissions and engine control systems
airstream flowing through the venturi. These vapors pass through the
intake manifold into the combustion chambers, where they are consumed during combustion.
5 The fuel filler cap incorporates a t w o -w a y relief valve that is closed
during normal operating conditions. The relief valve is calibrated t o open
when the fuel tank has a pressure of 1.5 psi, or a vacuum of 1.8 in-Hg.
Once the oressure or vacuum is relieved t o the atmosphere, t h e valve
returns t o i t s normally closed position.
Checking
6
Periodically, inspect the evaporative system vacuum hoses t o be
sure they are attached and in good condition. Refer t o the accompanying vacuum hose routing diagrams (see illustrations).
7 See Chapter for information regarding routine maintenance of
the canister.
F
3.6a
Fuel evaporative control system diagram for all US
vehicles with a four-cylinder engine
A
B
C
D
Canister purge tube assembly
Evaporative canister
Air cleaner assembly
EGR valve
E Throttle body assembly
F MAP sensor
G EGR solenoid
...I
ll)
<'Ii
E
~
~
3.6b Fuel evaporative control system diagram for
Canadian vehicles with a four-cylinder engine
A
B
C
D
E
Air cleaner assembly
EGR valve
Throttle body assembly
MAP sensor
EGR solenoid
lit..
The Motor Manual Guy
-------------------------------------6-9
G
3. 6c Fuel evaporative control system
diagram for all US vehicles with an
inline six-cylinder engine
A Canister purge tube
assembly
B Evaporative canister
C Air cleaner assembly
D EGR solenoid
E EGR valve
F Throttle body assembly
G MAPsensor
H Pressure regulator
B
D
C
3.6d Fuel evaporative control system
diagram for Canadian vehicles with an
inline six-cylinder engine
A
B
C
D
E
F
F
I
A
B
Air cleaner assembly
EGR solenoid
EGR valve
Throttle body assembly
MAPsensor
Pressure regulator
The Motor Manual Guy
6-10
4
Chapter 6 Emissions and engine control systems
~~=_=_=_=_=_=_=_=_=_=_=_==--------------------------
Thermostatic Air Cleaner 1
(carburetor
--:;ill~u:s~tr,:a:tio:n:s:----__
, --and
TBI-equipped vehicles T-A_c
4. 1 and 4.24
Refer to
General description
1 The Thermostatic Air Cleaner (TAC) (see illustration) provides
heated intake air during warmup, then maintains the inlet air
temperature within a 700F t o 105oF operating range by mixing warm
and cool air. This allows leaner fuel/air mixture settings for the carburetor, which reduces emissions and improves driveability.
2 Two fresh air inlets - one warm and one cold - are used. The
balance between the t w o is controlled by intake manifold vacuum. A
vacuum motor, which operates a heat duct valve in the air cleaner,
is actuated by intake vacuum.
3 When the underhood temperature is cold, warm air radiating off
the exhaust manifold is routed by a shroud which fits over the manifold
up through a hot air inlet tube and into the air cleaner. This provides
warm air for the carburetor or throttle body, resulting in better driveability and faster warmup. As the temperature inside the air cleaner
rises, the heat duct valve is gradually closed by the vacuum motor
(which, in turn is controlled by a bi-metal temperature sensor inside
the air cleaner) and the air cleaner draws air through a cold air duct
instead. The result is a consistent intake air temperature. A time delay
valve provides approximately 100 seconds delay before allowing the
heat duct valve to completely close.
4 On some models, a trap door system opens in a similar manner
to close off the air cleaner from the outside air when the engine is
inoperative.
Checking
General operation
Note: Make sure the engine is cold before beginning this test.
5 Always check the vacuum source and the integrity of all vacuum
hoses between the source and the vacuum motor before beginning
the following test. Do not proceed until they're okay.
6 Apply the parking brake and block the wheels.
7 Detach the flexible duct (if equipped) from the air cleaner snorkel
(see Chapter 4).
8 With the engine off, observe the heat duct valve inside the air
cleaner snorkel. It should be fully open (heat off position). If it isn't,
it might be binding or sticking. Make sure it's not rusted in an open
or closed position by attempting to move it by hand. If it's rusted, it
can usually be freed by cleaning and oiling the hinge. If it fails to work
properly after servicing, replace it.
9 Start the engine. Note the position of the heat duct valve. Now
it should be fully closed to incoming air (heat on position).
1 0 Have an assistant rapidly depress and release the accelerator 1/2
to 314 of its travel. The heat duct valve should briefly remain stationary,
move toward the heat off position, then back to the heat on position.
11 Loosely attach the flexible duct to the air cleaner and warm the
engine t o normal operating temperature. Remove the flexible duct and
observe the heat duct valve. It should be either fully open or at a mixture
position (half open) that provides the correct temperature for the inlet
air to the carburetor or throttle body.
1 2 Stop the engine and connect the flexible duct t o the air cleaner.
13 If the air valve does not function as described above, look for a
mechanical bind in the linkage and disconnected vacuum hoses or air
leaks at the vacuum motor, bi-metal sensor, time delay valve, check
valve, intake manfold or vacuum hoses.
1 4 If the heat duct valve manually operates freely and you cannot find
any hose disconnections or leaks, attach a hose from an intake manifold
vacuum source directly to the vacuum motor and start the engine.
a) If the heat duct valve closes, either the thermal switch, time delay
valve or check valve is defective.
b) If the heat duct valve does not close, replace the vacuum motor.
Bi-metal temperature sensor
15 Detach the t w o vacuum hoses from the sensor.
1 6 If necessary, remove the sensor (see the replacement procedure
below) and cool it below 40°F in a freezer.
17 Attach a vacuum pump to one of the sensor's vacuum fittings and
a vacuum gauge to the other fitting.
1 8 Apply 1 4 in-Hg vacuum to the sensor.
1 9 With the switch at a temperature below 400F, the gauge should
indicate a vacuum. Disconnect the vacuum pump momentarily to relieve
the vacuum.
2 0 Warm the switch above 55°F and again attempt to apply vacuum.
There should not be steady vacuum reading on the gauge.
21 Replace the sensor if it's defective.
Component replacement
Heat duct valve vacuum motor
2 2 Remove the air cleaner (see Chapter 4).
23 Clearly label, then detach the vacuum hoses from the heat duct
valve vacuum motor, bi-metal sensor and trap door vacuum motor (if
equipped).
2 4 Drill out the rivet which secures the heat duct valve vacuum motor
to the snorkel (see illustration).
25 Lift the motor and tilt it to one side to detach the motor linkage
from the heat duct valve assembly. Remove the motor.
26 Installation is the reverse of removal. If you don't have a rivet tool,
you'll need a self-tapping sheet metal screw of the correct diameter
t o attach the vacuum motor t o the snorkel. Make sure the rivet (or
the screw) does not interfere with the movement of the heat duct valve.
4.1 Cross-section diagram of the Thermostatic Air Cleaner (TAC) assembly used on
models - shown in open (heat off) position
6
1 Heat duct valve
3 Trap door time delay valve
7
8
vacuum motor
(not on all models)
2 Trap door vacuum motor
4 Vacuum source
9
10
(not on all models)
5 Bi-metal temperature sensor
carburetor and TBI-equipped
Check valve
Time delay valve
Heat duct valve
Heat duct
Cool air inlet
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
6-11
b) The air control valve controls the supply of filtered air routed to
the air injection check valve. The valve is opened and closed by
the air switch solenoid.
c) The air switch solenoid controls the air control valve by switching
vacuum to the air control valve on and off during varying operating conditions. The solenoid is controlled by the MCU.
d) Vacuum is stored in the vacuum storage reservoir until it's released by the air switch solenoid.
e) Depending on operating conditions, the MCU switches the air
injection point to and from the exhaust manifold and catalytic
converter. The MCU does this by energizing and de-energizing
the air switch solenoids.
Checking
4.24 To remove the heat duct valve vacuum motor,
remove the air cleaner assembly, disconnect the hoses,
then drill out the rivet (arrow)
Bi-metal temperature sensor
27 Remove the air cleaner (see Chapter 4).
28 Detach the t w o vacuum hoses from the sensor.
29 Pry up the tabs on the sensor retaining clip. Remove the clip, gasket
and sensor from the air cleaner. Before removing the sensor, note its
position in relation to the air cleaner to ensure proper reassembly.
30 Installation is the reverse of removal. Be sure to use a new gasket.
5
4 Because of the complexity of both the air pump and pulse air
systems, it's difficult t o diagnose either system at home. However,
if you suspect the system is malfunctioning, the following simple tests
will enable you to check each component.
5 Always begin the inspection of the system by carefully checking
all hoses, vacuum lines and wires. Be sure they are in good condition
and all connections are clean and tight. Make sure the pump drivebelt
is in good condition and properly adjusted.
Air pump system
Refer to illustration 5.6
6 To check the pump:
a) Start the engine and warm it up to normal operating temperature.
b) Locate the outlet hose attached t o the air pump (see illustration)
Air injection systems
General description
1 Four-cylinder and V6 models are equipped with air injection
systems which help reduce hydrocarbons and carbon monoxide levels
in the exhaust by injecting air into the exhaust stream. During cold
engine operation, air is injected directly into the exhaust port; during
normal operation, it's injected into the catalytic converter. Two types
of air injection systems are used on these vehicles: An air pump system
is used on V6 models and a Pulse Air system is used on four-cylinder
models.
6
Air pump system
2 The air injection system on V6 models uses a belt-driven pump
to pump air into the exhaust. The system includes the pump itself, an
air management valve (or a trio of separate air control, air switching
and air diverter valves on some models), an air injection manifold for
each cylinder head (or, on California models, a single manifold on the
right side of the engine), one or t w o check valves and the hoses connecting the components. The air management valve (or air control/
switching/diverter valves), which is controlled by the vehicle's computer, directs the air t o the correct location, depending on engine
temperature and driving conditions. Note: The computer may be referred to as the Electronic Control Module (ECM), Electronic Control Unit
(ECU) or the Microcomputer Unit (MCV). During certain situations, such
as decleration, the air is diverted to the air cleaner to prevent backfiring
from too much oxygen in the exhaust stream. The check valve(s) prevent exhaust gases from being forced back through the system.
5.6 Exploded view of a typical air injection system (V6 models)
Pulse air system
3 The Pulse Air system uses the alternating pressure and vacuum
pulsations created in the exhaust system - instead of an air pump
to draw air into the exhaust system. Air is supplied from the filtered
side of the air cleaner through a hose t o the air control valve, which
is controlled by the MCU. When opened by the air switch solenoid,
the air control valve allows air to flow t o the air injection check valve,
through which it enters the exhaust system. The following explains
the components of the system:
a) The air injection check valve is a reed valve that is opened and
closed by the vacuum and pressure exhaust pulsations. During
vacuum pulsations, atmospheric pressure opens the check valve
and forces air into the exhaust system.
2
3
4
5
6
7
8
9
10
Left air injection manifold
(49-state and Canada only)
Left check valve 149-state
and Canada only)
Air hose to left check valve
(49-state and Canada only)
Air hose to right check valve
Air pump outlet hose
Air pump
Right air injection manifold
Right check valve
Air hose from diverter
valve to air cleaner
Diverter valve
The Motor Manual Guy
6-12
Chapter 6 Emissions and engine control systems
and, with the engine operating at about 1500 rpm, squeeze the
hose. You should be able to feel the air pulsing through the hose.
c) Have an assistant increase the engine speed. There should be
a proportional increase in air flow. If there is, the pump is working
properly. If there isn't, the pump is malfunctioning. Replace it
(see the component replacement procedure below).
7 To test a check valve:
a) Remove it (see the component replacement procedure below).
b) Clean it off thoroughly.
c) Try t o blow through it from each end. Air should only pass
through it in the direction of normal flow (towards the exhaust
manifold). If the valve is open both ways or closed both ways,
replace it.
Pulse air system
8 Checking the pulse air system is beyond the scope of the home
mechanic and can be hazardous under certain circumstances. Take the
vehicle to a dealer service department or a certified emission control
repair shop for testing.
Component replacement
Refer to illustrations 5. 11, 5.14, 5.19, 5.30 and 5.32
9 Always detach the cable from the negative terminal of the battery
before replacing any of the following components.
Drivebelt (air pump system only)
1 0 Drivebelt replacement procedures are in Chapter 1.
Air pump pulley and filter
11 Compress the drivebelt to prevent the pulley from turning and
loosen the pulley attaching bolts (see illustration).
1 2 Remove the drivebelt (see Chapter 1 ).
1 3 Remove the pulley attaching bolts and detach the pulley.
1 4 To remove the air pump filter, grasp it firmly with needle nosepliers (see illustration) and pull it from the pump. Caution: The filter
will probably be damaged when you pull it off, so make sure no
fragments fall into the air intake hose. Don't insert a screwdriver between the filter and the pump housing - you might damage the edge
of the housing.
1 5 To install the new filter, place it in position, place the pulley in position and tighten the pulley bolts evenly. As the pulley bolts are tightened,
the pulley will press the filter into the pump. Caution: Do not attempt
to install a filter by pressing or hammering it into place.
16 The remainder of installation is the reverse of removal. Note: It
is normal for the new filter to have an interference fit with the pump
housing. It may squeal in operation until it's worn in.
Hoses and tubes
17 Before replacing any hose or tube, note how it is routed. Make
a sketch or label the components to which it's attached.
18 Be sure t o replace old hoses or tubes with new ones of the same
size and material. Tighten all connections securely.
Check valve(s) (air pump system only)
1 9 Remove the hose clamp and detach the air hose from the check
valve(s) (see illustration).
2 0 Unscrew the check valve from the air injection manifold. Use a
backup wrench so you don't bend or twist the manifold.
21 Installation is the reverse of removal. If you are replacing the valve,
compare the new valve with the old one to be sure you have the correct
replacement.
Diverter valve (air pump system only)
2 2 Detach the vacuum signal line and the air hoses from the diverter
valve (see illustration 5.6).
23 Remove the mounting bolts (the bolts may have tabbed lock
washers which you will have to bend back).
2 4 lnstallation is the reverse of removal.
Air injection manifold(s) (air pump system only)
5.11 To remove the air pump pulley, loosen the three
bolts, remove the drivebelt, then remove the bolts
5.14 To remove the air pump filter, grasp it firmly with
needle-nose pliers and pull it from the pump - be sure no
filter fragments fall into the air intake hose!
25 Detach the air hose(s) from the air injection manifold check valve(s)
(see the check valve replacement procedure above).
26 Using a flare nut wrench (if available), unscrew the three fittings
that attach each air injection manifold to its associated exhaust manifold
(see illustration 5 . 6 ) .
5.19 To remove a check valve, loosen the hose clamp
and detach the air hose from the valve, then unscrew the
valve from the air injection manifold
be sure t o use a
backup wrench so you don't damage the manifold
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
27 Installation is the reverse of removal. Be sure to coat the threads
of the air injection manifold fittings with Fel-Pro C 100 anti-seize compound or equivalent.
6-13
3 0 Remove the attaching bolts and nut (see illustration) and remove
the pump.
31 Installation is the reverse of removal.
Air pump
28 Remove the drivebelt and pulley (see the air pump replacement
procedure above).
29 Detach the air pump outlet hose (see illustration 5.6).
Pulse air system
3 2 To replace pulse air system components, refer to the accompanying
exploded view of the pulse air system (see illustration).
3
~2
1
~3
5.30 Air pump installation details - when removing only the
pump, unscrew the two attaching bolts and nut (arrows)
5.32
Exploded view of a typical
Pulse Air system
I Air cleaner
2 Air cleaner-to-downstream air
control valve vacuum hose
3 Air cleaner-to-upstream air
control valve vacuum hose
4 Upstream vacuum hose
5 Upstream air control valve
6 Downstream air control valve
7 Upstream check valve hose
8 Downstream vacuum hose
9 Downstream check
valve hose
10 Upstream check valve
11 Downstream check valve
12 Downstream
tube-to-converter
A Air switch solenoid
(upstream)
B Air switch solenoid
(downstream)
C Control wires from MCU
(downstreaml
D Control wires from MCU
(upstream)
E Vacuum storage reservoir
6
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
6-14
6
Exhaust Gas Recirculation (EGR) system
General description
1 High combustion temperatures raise the level of NOx (oxides of
nitrogen) emissions in the exhaust. The Exhaust Gas Recirculation (EGR)
system lowers NOx levels by allowing small amounts of exhaust gas
into the combustion chamber to reduce combustion temperature.
2 The principal component of all EGR systems used on vehicles
covered by this manual is the EGR valve itself. The EGR valve is a backpressure or vacuum controlled device which regulates the amount of
exhaust gas bled into the intake. The EGR valve is usually open during
warm engine operation and anytime the engine is running above idle
speed. The amount of gas recirculated is controlled by variations in
vacuum and exhaust backpressure.
3 The vacuum supply for the EGR valve is controlled by an EGR valve
solenoid which is in turn controlled by the Electronic Control Module
(ECM) or Electroninic Control Unit (ECU). When energized by the ECM
or ECU, the solenoid closes and prevents vacuum from reaching the
EGR valve. When it's not energized, the solenoid is open and vacuum
is applied to the EGR valve. The ECM or ECU monitors engine coolant
temperature and other operating conditions to determine when EGR
operation is desired.
4 On inline six-cylinder engines, a vacuum transducer is installed inline between the EGR valve solenoid and the EGR valve. The transducer
is controlled by exhaust backpressure. When backpressure exceeds
a preset value, the transducer allows vacuum to actuate the EGR valve.
5 Common engine problems associated with the EGR system are
rough idling, stalling at idle, rough engine performance during light
throttle application and stalling during deceleration.
Checking
Refer to illustrations 6.8a, 6.Bb, 6. l a and 6.1 1b
EGR valve
6
7
Perform the EGR valve checking procedures in Chapter 1.
If the EGR valve appears to be in proper operating condition,
carefully check all hoses connected to the valve for cracks, leaks and
kinks. Replace or repair the valve and hoses as necessary.
8 With the engine idling at normal operating temperature, detach the
vacuum hose from the EGR valve and connect a vacuum pump. Note:
On four-cylinder and inline six-cylinder engines, the EGR valves are
located where shown (see illustrations). On V6 engines, the EGR valve
is located on the intake manifold, in front of the carburetor or throttle
body. If the EGR valve is operating properly, the engine should stumble
or stall when you apply vacuum. Replace the EGR valve with a new
one if the idle remains unchanged.
9 Because of the EGR system's interrelationship with the ECM or
ECU, further checks of the system are beyond the scope of the home
mechanic. Have the system checked by a dealer service department
or certified emission control repair shop.
EGR valve solenoid
1 0 Warm the engine up t o normal operating temperature.
11 With the engine idling, detach the vacuum hose at the solenoid
vacuum source (see illustrations) and attach a vacuum gauge to the
hose. Verify the vacuum is at least 15 in-Hg.
a) If vacuum is low, check the hose for kinks, twists or a loose connection at the manifold fitting.
b) If vacuum is okay, detach the gauge, reattach the hose and proceed to the next step.
12 Detach the hose at the solenoid output port and attach a vacuum
gauge to the port. The vacuum reading should be zero.
a) If the vacuum reading is zero, leave the gauge connected and
proceed to the next step.
b) If vacuum is present, have the solenoid and/or ECU checked by
a dealer service department (special tools are required for further
checking).
1 3 Detach the electrical connector at the solenoid and determine
whether there is vacuum at the solenoid output port. Vacuum should
now be present at the output port.
a) If vacuum is present, the EGR valve may be faulty. See the EGR
checking procedure above.
b) If vacuum isn't present, replace the EGR valve solenoid.
l
6.8a Location of the EGR valve on four-cylinder
models - when checking the valve, remove the vacuum
hose and connect a hand vacuum pump
6.8b Location of the EGR valve on inline six-cylinder
models - when checking the valve, detach the vacuum
hose (arrow) - when removing the valve, detach the
transducer vacuum inlet hose
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
6.1 1b
6.1 1a
Solenoid vacuum source
2 Intake manifold
vacuum fitting
Refer t o this schematic when testing the EGR
system on an inline six-cylinder model
I
2
3
4
5
Refer t o this schematic when testing the EGR
system on a four-cylinder model
3 Solenoid output port
4 EGR vacuum hose
6-15
Solenoid vacuum source
Vacuum connector
Solenoid output port
EGR vacuum hose
EGR valve nipple
EGR tube (four-cylinder engine)
Component replacement
Refer to illustrations 6.19 and 6.24
EGR valve
1 4 Detach the vacuum hose from the EGR valve or EGR valve vacuum
transducer (see illustrations 6.8a and 6.8b).
1 5 Remove the t w o EGR valve mounting bolts.
16 Remove the EGR valve and gasket. Discard the gasket.
1 7 Clean the gasket mating surfaces of the EGR valve and intake manifold.
1 8 lnstallation is the reverse of removal. Be sure t o use a new gasket.
19 Remove the EGR tube-to-exhaust manifold bolts (see illustration).
2 0 Using a flare nut wrench (if available), unscrew the EGR tube nut
at the intake manifold.
2 1 Remove the tube and discard the gasket.
2 2 lnstallation is the reverse of removal. Be sure t o use a n e w gasket
and tighten the bolts and nut securely.
EGR tube (inline six-cylinder engine)
2 3 Loosen the exhaust manifold mounting bolts (see Chapter 2,
Part Cl.
2 4 Using a flare nut wrench (if available), loosen the EGR tube line
nuts at the intake and exhaust manifolds (see illustration).
6
-------~-----1
INTAKE MANIFOLD
NUT
I
~
6.19 To remove the EGR tube on a four-cylinder engine,
remove the bolts, then unscrew the nut with a flare nut
wrench (if available)
6.24
On an ;ono, six-cylinder
u model, unscrew the line
nuts with a flare nut wrench (if available)
J
"--'----------
The Motor Manual Guy
6-16
Chapter 6 Emissions and engine control systems
25 Remove the EGR tube.
26 Install the EGR tube, but don't tighten the line nuts at this time.
27 Tighten the intake manifold line nut, then the exhaust manifold line
nut. Tighten them to the torques specified in Chapter 2, Part C.
28 Tighten the exhaust manifold mounting bolts to the torque specified in Chapter 2, Part C.
and then sends a command to the carburetor Mixture Control (M/C)
solenoid, telling it to change the fuel/air mixture. To be effective, all
this happens in a fraction of a second, and it goes on continuously
while the engine is running. The end result is a fuel/air mixture which is
constantly kept at a predetermined ratio, regardless of driving conditions.
Testing
7
Catalytic converter
Note: Because of a Federally mandated extended warranty which covers emissions-related components such as the catalytic converter,
check with a dealer service department before replacing the converter
at your own expense.
General description
1 The catalytic converter is an emission control device added to the
exhaust system to reduce pollutants from the exhaust gas stream.
Two types of converters are used. Your vehicle may be equipped with
either of the two. The conventional oxidation catalyst reduces the levels of hydrocarbon (HC) and carbon monoxide (CO). The three-way
catalyst lowers the levels of oxides of nitrogen (NOx) as well as hydrocarbons (HC) and carbon monoxide (CO).
Checking
2 The test equipment for a catalytic converter is expensive and
highly sophisticated. If you suspect that the converter on your vehicle
is malfunctioning, take it to a dealer or authorized emissions inspection facility for diagnosis and repair.
3 Whenever the vehicle is raised for servicing of underbody components, check the converter for leaks, corrosion, dents and other damage. Check the welds/flange bolts that attach the front and rear ends
of the converter to the exhaust system. If damage is discovered, the
converter should be replaced.
4 Although catalytic converters don't break too often, they do become plugged. The easiest way to check for a restricted converter is
to use a vacuum gauge to diagnose the effect of a blocked exhaust on
intake vacuum.
a) Open the throttle until the engine speed is about 2000 RPM.
b) Release the throttle quickly.
c) If there is no restriction, the gauge will quickly drop to not more
than 2 in Hg or more above its normal reading.
d) If the gauge does not show 5 in Hg or more above its normal
reading, or seems to momentarily hover around its highest reading for a moment before it returns, the exhaust system, or the
converter, is plugged (or an exhaust pipe is bent or dented, or the
core inside the muffler has shifted).
One might think that a system which uses exotic electrical sensors
and is controlled by an on-board computer would be difficult to diagnose. This is not necessarily the case.
The Computer Command Control System has a built-in diagnostic
system which indicates a problem by flashing a CHECK ENGINE light
on the instrument panel. When this light comes on during normal vehicle operation, a fault has been detected.
Perhaps more importantly, the ECM will recognize this fault in a
particular system monitored by one of the various information sensors
and store it in its memory in the form of a trouble code. Although the
trouble code cannot reveal the exact cause of the malfunction, it
greatly facilitates diagnosis as you or a professional mechanic can
"tap into" the ECM's memory and be directed to the problem area.
Retrieving codes
To extract this information from the ECM memory, you must use a
short jumper wire to ground terminals 6 and 7 on the diagnostic connector (see illustration). The diagnostic connector is located in the
engine compartment on the left (driver's side) fenderwell. Caution: Do
not start the engine with the terminals grounded.
Turn the ignition to the On position - not the Start position. The
CHECK ENGINE light should flash Trouble Code 12, indicating that the
diagnostic system is working. Code 12 will consist of one flash, followed by a short pause, and then two flashes in quick succession. After a longer pause, the code will repeat itself two more times.
If no other codes have been stored, Code 12 will continue to repeat itself until the jumper wire is disconnected. If additional Trouble
Codes have been stored, they will follow Code 12. Again, each Trouble
Code will flash three times before moving on.
Once the code(s) have been noted, use the Trouble Code chart to
locate the source of the fault.
It should be noted that the self-diagnosis feature built into this system does not detect all possible faults. If you suspect a problem with
the Computer Command Control System, but the CHECK ENGINE
light has not come on and no trouble codes have been stored, take the
vehicle to a dealer service department or other repair shop for diagnosis.
Component replacement
5
8
Refer to the information and diagrams in Chapter 4.
Computer Command Control System (CCCS) and trouble
codes (V6 models) - description and trouble code retrieving
02
Refer to illustration 8.7
General description
This electronically controlled emissions and engine control system
is linked with as many as nine other related emissions systems. It consists mainly of sensors and an Electronic Control Module (ECM). Completing the system are various engine components which respond to
commands from the ECM.
In many ways, this system can be compared to the central nervous
system in the human body. The sensors (nerves) constantly gather information and send this data to the ECM (brain), which processes the
data and, if necessary, sends out a command for some type of vehicle
(body) change.
Here's a specific example of how one portion of this system operates. An oxygen sensor, mounted in the exhaust manifold and protruding into the exhaust gas stream, constantly monitors the oxygen content of the exhaust gas as it travels through the exhaust pipe. If the
percentage of oxygen in the exhaust gas is incorrect, an electrical signal is sent to the ECM. The ECM takes this information, processes it
01
8.7 To extract trouble codes on V6 models, bridge terminals 6
and 7 of the diagnostic connector together with a jumper wire
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
Furthermore, when diagnosing an engine performance, fuel economy or exhaust emissions problem (which is not accompanied by a
CHECK ENGINE light) do not automatically assume the fault lies in this
system. Perform all standard troubleshooting procedures, as indicated
elsewhere in this manual, before turning to the Computer Command
Control System .
Finally, since this is an electronic system, you should have a basic
knowledge of automotive electronics before attempting any diagnosis.
Damage to the ECM or related components can easily occur if care is
not exercised.
Trouble Code Identification
Refer to the accompanying chart for a list of the typical trouble
codes which may be encountered while diagnosing the Computer
6-17
Command Control System. Also included are simplified troubleshooting procedures. If the problem persists after these checks have been
made, the vehicle must be diagnosed by a professional mechanic who
can use specialized diagnostic tools and advanced troubleshooting
methods to check the system. Procedures marked with an asterisk (*)
indicate component replacements which may not cure the problem in
all cases. For this reason, you may want to seek professional advice
before purchasing replacement parts.
To clear the Trouble Code(s) from the ECM memory, detach the
negative ( - ) battery cable for at least 10 seconds. Disconnecting the
power to the ECM to clear the memory can be an important diagnostic
tool, especially on intermittent problems. Caution: To prevent damage
to the ECM, the ignition switch must be off when disconnecting or
connectingpower to the ECM.
Trouble code chart 1984 through 1986 V6 models
Trouble Code
Circuit or system
Probable cause
12 (one flash, pause, two flashes)
No reference pulses to ECM
This code should flash whenever the test terminal is grounded with the
ignition On and the engine not running. If additional trouble codes are
stored (indicating a problem), they will appear after this code has flashed
three times. With the engine running, the appearance of this code indicates that no references from the distributor are reaching the ECM
Carefully check the four-terminal EST connector ar the distributor.
13 (one flash, pause, three flashes)
Oxygen sensor circuit
Check for a sticking or misadjusted throttle position sensor. Check the
wiring and connectors from the oxygen sensor. Replace oxygen sensor*
(see Chapter 1).
14 (one flash, pause, four flashes)
Coolant sensor circuit
If the engine is experiencing overheating problems the problem must be
rectified before continuing (see Chapters 1 and 3). Check all wiring and
connectors associated with the sensor. Replace the coolant sensor*.
15 (one flash, pause, five flashes)
Coolant sensor circuit
(low temperature indicated)
See above.
21 (two flashes, pause, one flash)
TPS circuit (signal voltage high) Check for sticking or misadjusted TPS. Check all wiring and connections
at the TPS and at the ECM Adjust or replace TPS*.
23 (two flashes, pause, three flashes) Mixture Control (M/C)
solenoid circuit
Check the electrical connections at the M/C solenoid (see Chapter4). If
OK, clear the ECM memory and recheck for code(s) after driving the vehicle. Check wiring connections at the ECM. Check wiring from M/C
solenoid.
34 (three flashes, pause, four flashes) Manifold Absolute Pressure
(MAP) sensor circuit
Check the hose to the MAP sensor for a leak. Check the wiring from
the MAP sensor to the ECM. Check the connections at the ECM and the
sensor. Replace the MAP sensor.*
41 (four flashes, pause, one flash)
No distributor signals
Check all wires and connections at the distributor. Check distributor
pick-up coil connections (see Chapter 5).
42 (four flashes, pause, two flashes)
Bypass or EST problem
If the vehicle will start and run, check the wire leading to ECM terminal
12. An improper HE! module can also cause this trouble code.
44 (four flashes, pause, four flashes)
Lean exhaust
Check for a sticking M/C solenoid (Chapter 4). Check ECM wiring connections, particularly terminals 14 and 9. Check for vacuum leakage at
carburetor base gasket, vacuum hoses or intake manifold gasket. Check
for air leakage at air management system-to-exhaustports and at decel
valve Replace oxygen sensor.*
44 and 45 at the same time
Oxygen sensor or circuit
Check the oxygen sensor circuit. Replace the oxygen sensor.*
45 (four flashes, pause, five flashes)
Rich exhaust
Check for a sticking M/C solenoid (Chapter 4). Check wiring at M/C
solenoid connector. Check the evaporative charcoal canister and its
components for the presence of fuel (Chapters 1, 6). Replace oxygen
sensor.*
51 (five flashes, pause, one flash)
PROM problem
Diagnosis should be performed by a dealer service department or other
repair shop.
54 (five flashes, pause, four flashes)
Mixture control (M/C) solenoid
Check all M/C solenoid and ECM wires and connections Replace the
M/C solenoid* (see Chapter 4).
55 (five flashes, pause, five flashes)
Reference voltage problem
Check for a short circuit to ground on the wire to ECM terminal 21. Possible faulty ECM or oxygen sensor.
6
The Motor Manual Guy
6-18
Chapter 6 Emissions and engine control systems
9.3 Wrap the threads of the coolant temperature sensor with
Teflon tape to prevent leaks
9
Information sensors (V6 models)
Note: After performing any checking procedure to any of the information sensors, be sure to clear the ECM o f all trouble codes by disconnecting the cable from the negative terminal of the battery for at least
ten seconds.
Engine coolant temperature sensor
Refer to illustration 9.3
General description
1 The coolant sensor is a thermistor (a resistor which varies the
value of its resistance in accordance with temperature changes). A failure in the coolant temperature sensor circuit should set either a Code
14 or a Code 15. These codes indicate a failure in the coolant temperature sensor circuit, so the appropriate solution to the problem will be
either repair of a wire or replacement of the sensor
9.6 Typical MAP sensor installation details
1
2
MAP sensor
Mounting screw
3
4
Vacuum line
Electrical connector
corresponding terminals in the electrical connector. Connect the positive lead of a high-impedance digital voltmeter to terminal B (the center terminal) of the sensor and the negative lead to ground. With the ignition On (engine not running) the voltage reading should be about 4.5
to 5 volts. Start the engine and let it warm up. The reading should now
be different from the original reading, and should fluctuate with
changes in engine rpm. If it doesn't, check the vacuum hose for
breaks, blockage and vacuum when the engine is running. If the hose
and vacuum signal are OK, the sensor is probably bad. A malfunctioning MAP sensor will usually cause a Code 34 to be stored.
Replacement
8 To replace the sensor, detach the vacuum hose, unplug the electrical connector and remove the mounting screws (see illustration 9.6). Installation is the reverse of removal.
Oxygen sensor
Check
General description
2 Unplug the electrical connector and use an ohmmeter to measure
the resistance across the sensor terminals with the engine cold. Warm
the engine up and take another measurement. If the difference in resistance readings is not approximately 500 ohms, the sensor is probably
bad.
9 The oxygen sensor is mounted in the exhaust system where it can
monitor the oxygen content of the exhaust gas stream. By monitoring
the voltage output of the oxygen sensor, the ECM will know what fuel
mixture command to give the mixture control solenoid in the carburetor.
10 The oxygen sensor produces no voltage when it's below its normal
operating temperature of about 600-degrees F. During this initial period before warm up, the ECM operates in open loop mode.
11 If the engine reaches normal operating temperature and/or has
been running for two or more minutes, and if the oxygen sensor is producing a steady signal voltage between 0.35 and 0.55-volt, even
though the TPS indicates the engine isn't at idle, the ECM will set a
Code 13.
12 A delay of two minutes or more between engine start-up and normal operation or the sensor, followed by a low voltage signal or a short
in the sensor circuit, will cause the ECM to set a Code 44. If a high
voltage signal occurs, the ECM will set a Code 45.
13 When any of the above codes occur, the ECM operates in the
open loop mode -that is, it controls fuel delivery in accordance with a
programmed default value instead of feedback information from the
oxygen sensor.
Replacement
Warning: Wait until the engine is completely cool before beginning this
procedure. Also, remove the radiator cap to release any residual pressure that may be present in the cooling system, then reinstall the cap.
Read the antifreeze warning in Chapter 3.
3 Prepare the new sensor for installation by wrapping the threads
with Teflon sealing tape to prevent leakage and thread corrosion (see
illustration).
4 To remove the sensor, release the locking tab (see illustration),
unplug the electrical connector, then carefully unscrew the sensor. Be
prepared for coolant leakage and install the new sensor as quickly as
possible. Caution: Handle the coolant sensor with care. Damage to
this sensor will affect the operation of the entire fuel injection system.
5 Installation is the reverse of removal. Check the coolant level and
add some, if necessary, to bring it to the proper level (see Chapter 1).
Manifold Absolute Pressure (MAP) sensor
Check
Refer to illustration 9.6
14 The sensor can be checked with a high-impedance digital voltmeter. Warm up the engine to normal operating temperature, then turn
the engine off. Unplug the oxygen sensor electrical connector and
connect the positive probe of the voltmeter to the sensor side of the
connector. Caution: Don't let the sensor wire or the voltmeter lead
touch the exhaust pipe or manifold. Ground the negative probe of the
meter, turn the meter to the millivolt setting and start the engine.
15 The reading on the voltmeter should fluctuate between 100 and
1,000 millivolts (0.1 and 1.0 volts). If the meter reading doesn't fluctuate, the sensor is probably bad (although a fuel system problem could
be the cause).
General description
6 The Manifold Absolute Pressure (MAP) sensor (see illustration)
monitors the intake manifold pressure changes resulting from changes
in engine load and speed and converts the information into a voltage
output. The ECM uses the MAP sensor to control fuel delivery and ignition timing.
Check
7 Unplug the electrical connector from the sensor and, using jumper
wires, connect terminals A and C (the two outside terminals) to their
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
6-19
Replacement
16 Refer to Chapter 1 for the oxygen sensor replacement procedure.
Throttle Position Sensor (TPS)
T.P.S. ASSEMBLY
General description
17 The Throttle Position Sensor (TPS) is located on the carburetor
float bowl.
18 By monitoring the output voltage from the TPS, the ECM can determine fuel delivery based on throttle valve angle (driver demand). A
broken or loose TPS can cause intermittent bursts of fuel from the injector and an unstable idle because the ECM thinks the throttle is
moving.
19 A problem in any of the TPS circuits will set a Code 21. Once a
trouble code is set, the ECM will use an artificial default value for TPS
and some vehicle performance will return.
Check
20 Unplug the TPS electrical connector. Using a digital ohmmeter,
connect the positive probe to the center terminal and the negative
probe to each of the outside terminal (in turn).
21 With the ignition On, slowly move the throttle lever until it is wide
open and observe the resistance readings. If the resistance readings
are jerky and inconsistent instead of gradual and progressive, replace
the TPS with a new part.
Replacement
Refer to illustration 9.24
22 Detach the negative battery cable.
23 Unplug the TPS electrical connector.
24 Remove the top of the carburetor (see Chapter 4), then grasp the
TPS assembly and lift it up out of the carburetor body (see illustration).
25 Installation is the reverse of removal.
Adjustment
26 Carefully drill a small hole in the plug that covers the TPS adjustment screw, then pry the plug from its bore with a small pick or awl.
Caution: When drilling the hole, be careful not to damage the head of
the adjusting screw.
27 Disconnect the electrical connector from the TPS and connect the
corresponding terminals of the connector and the TPS with jumper
wires (you'll have to fabricate these using the proper terminals, which
are generally available at auto parts stores or electronics supply
stores).Strip a small portion from the center of the wires connected to
terminals B and C.
28 Connect the probes of a high-impedance digital voltmeter to the
stripped portion of the wires connecting terminals B and C.
29 Check to be sure that the air conditioner is turned off and the
throttle lever is at its curb idle position. With the engine off and the ignition key turned to the On position, turn the TPS adjusting screw one
way or the other until a reading of 0.026 volts is obtained.
30 Turn the ignition Off, remove the jumper wires and reconnect the
electrical connector. Install a new plug in the hole over the adjustment
screw. If a plug isn't available, plug the hole with RTV sealant.
10
1
Self-diagnosis codes (1991 and later models)
and trouble code retrieving
- description
The computerized emissions control systems in 1991 and later
9.24 To remove the TPS from the E2SE carburetor, push up from
the bottom of the electrical connector and remove the TPS from
the float bowl (also remove the spring from the bottom of the
float bowl)
models are equipped with a self-diagnosis function that stores codes
in the computer which you can retrieve. These codes indicate any areas of trouble in the system. Often, when a self-diagnosis code (sometimes referred to as a "trouble" code) is stored in the computer, a
CHECK ENGINE or POWER LOSS light will illuminate on the dash
panel.
2 Prior to obtaining the codes, set the parking brake and put the
transmission in Park (automatic)or Neutral (manual). Raise the engine
speed to approximately 2500 rpm and slowly let the speed down to
idle. Also cycle the air conditioning system on briefly, then off (if
equipped). Next, if the vehicle is equipped with an automatic transmission, with your foot on the brake, select each position on the transmission (Reverse, Drive, Low, etc.) and bring the shifter back to Park.
3
To display the codes, turn the ignition key ON, OFF, ON, OFF and
finally ON. The codes will begin to flash on the CHECK ENGINE light.
The light will blink the number of the first digit then pause and blink the
number of the second digit. For example: Code 23, the MAT sensor
circuit. would be indicated by two flashes, then a pause (about 2 seconds) followed by three flashes. If more than one code is being accessed, the pause between codes is about 3 or 4 seconds.
4
Certain criteria must be met for a fault code to be entered into the
computer memory. The criteria may be a specific range of engine rpm,
engine temperature or input voltage to the computer. It is possible that
a fault code for a particular monitored circuit may not be entered into
the memory despite a malfunction. This may happen because one of
the fault code criteria has not been met.
5
The accompanying table is a list of the typical trouble codes which
may be encountered while diagnosing the system. Also included in
this Chapter are simplified testing procedures. If the problem persists
after checks have been made, or if you are not certain which compo-
nent is malfunctioning, more detailed service procedures will have to
be performed by a dealer service department or other qualified repair
shop. Procedures marked with an asterisk (*) indicate component replacements which may not cure the problem in all cases. For this reason, you may want to seek professional advice before purchasing replacement parts.
Trouble code chart 1991 and later models
Code
Circuit or system
Probable cause
11
No crank reference signal to computer
Check the circuit from the crankshaft position sensor to the PCM (computer). Replace
the crankshaft position sensor.*
13
Manifold Absolute Pressure (MAP) sensor
No change indicated between barometric pressure (engine off) and manifold vacuum
(engine on). Check MAP sensor and circuit. Replace MAP sensor.*
14
Manifold Absolute Pressure (MAP) sensor
MAP sensor voltage too high or low. Check MAP sensor and circuit. Replace MAP sensor.
15
Distance sensor or circuit
No distance sensor signal detected by computer. Check circuit. Replace sensor.*
17
Engine running too cool
Check thermostat for proper operation. Check coolant sensor and circuit. Replace
coolant sensor.*
6
The Motor Manual Guy
6-20
Chapter 6 Emissions and engine control systems
Trouble code chart 1991 and later models
Code
Circuit or system
Probable cause
21
Oxygen sensor or circuit
Check oxygen sensor and circuit. Replace sensor.*
22
Coolant temperature sensor or circuit
Check coolant temperature sensor circuit. Check sensor resistance. Replace sensor.*
23
MAT sensor or circuit
Check MAT sensor circuit. Check sensor resistance. Replace sensor.*
24
Throttle Position Sensor (TPS)
sensor or circuit
Check TPS sensor circuit. Check sensor voltage outputs. Replace sensor.*
25
Idle Air Control (IAC) circuit
Check IAC sensor circuit. Replace sensor.*
27
Fuel injector control circuit
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
33
Air conditioning clutch relay
Check the circuit to the A/C clutch for an open or short-circuit condition.
34
Cruise control circuit
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
35
Cooling fan relay circuit
Check the cooling fan circuit and relay. Replace relay.*
41
Alternator field not switching properly
Check the charging system (see Chapter 5). Further diagnosis should be performed
by a dealer service department or other repair shop.
42
Automatic shutdown relay or control circuit
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
44
Battery temperature sensor
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
46
Battery over voltage
Check the charging system (see Chapter 5).
47
Battery under voltage
Check the charging system (see Chapter 5).
51
Oxygen sensor - lean condition indicated
Check the oxygen sensor and circuit. Check for vacuum leaks. Replace oxygen sensor.*
52
Oxygen sensor - rich condition indicated
Check fuel injection system. Replace oxygen sensor.*
53
Powertrain Control Module (PCM) problem
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
54
Distributor sync pickup
Replace sync sensor in distributor.*
55
End of Code Output
Trouble code sequence complete.
62
Emissions Maintenance Reminder (EMR)
mileage accumulator Or PCM
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
63
Controller failure EEPROM write denied
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
76
Fuel pump resistor bypass relay circuit
Have the vehicle diagnosed at a dealer service department or other qualified repair shop.
11
lnformation sensors (1991 and later models)
1 lnformation sensors inform the computer of the engine's current
operating conditions so adjustments (air/fuel mixture, ignition timing,
idle speed, etc.) can be made to achieve lower emissions and improved fuel economy. For more information on the computerized
emissions control system, see Section 8. Note: Because of a Federally
mandated extended warranty which covers emissions-related components such as the information sensors, check with a dealer service department before replacing the sensors at your own expense.
Oxygen sensor
Refer to illustration 11.2
General description
2 The Oxygen
sensor is located in the exhaust manifold or exhaust down pipe (see illustration).It provides a variable voltage signal
(about 0 to 1 volt) to the computer, based on the oxygen content in the
exhaust. The computer uses this information to determine whether or
not the fuel/air mixture needs to be altered by adjusting the pulse
width of the fuel injectors. The oxygen sensor is normally replaced at
the specified mileage (see Chapter 1).
Check and replacement
3 With the engine off and at normal operating temperature, disconnect the sensor electrical connector, insert the positive probe of a
high-impedance voltmeter into the connector terminal (on the sensor
side) and ground the negative lead. Start the engine and check to see
if the reading fluctuates between 0.1 and 1.0 volts (100 to 1000 millivolts). If it doesn't, the sensor is faulty and should be replaced. On
some models the oxygen sensor incorporates a heating element. With
the engine cold, unplug the sensor connector and touch the ohmmeter
leads across the white wire terminals. The reading should be between
5 and 7 ohms. The sensor is faulty if the ohmmeter displays an open
circuit (infinity).Refer to Chapter 1 for the oxygen sensor replacement
procedure.
11.2 An oxygen sensor located in the exhaust manifold (arrow)
Knock sensor
Refer to illustration 11.4
General description
4 A knock sensor (see illustration) is used on some models. The
knock sensor is on the left side of the engine block, above the oil pan
on six-cylinder models and threaded into the intake manifold on fourcylinder models. The sensor is a piezoelectric crystal transducer that
indicates detonation (knock) during engine operation by sending small
electric impulses to the computer. The computer then retards the ignition to eliminate detonation (knock).
Check
5
A simple check of the knock sensor can be made by connecting a
The Motor Manual Guy
Chapter 6 Emissions and engine control systems
6-21
11.13 The Coolant Temperature Sensor (CTS) is normally mounted
in the thermostat housing
11.4 The knock sensor (arrow) is located on the engine block
(on six-cylinder models - shown) or on the intake manifold
(four-cylinder models)
timing light in accordance with the tool manufacturers instructions,
then starting the engine. Have an assistant strike the engine block near
the sensor while you observe the timing marks. If the timing retards,
the system is operating properly. If it doesn't, either the sensor or its
circuit is faulty.
Replacement
6 If necessary for access to the sensor, raise the front of the vehicle
and support it securely on jackstands.
7 Disconnect the knock sensor electrical connector.
8 Carefully unscrew the sensor.
9 Clean the threaded hole of any corrosion and old sealant. Use
Teflon tape on the threads of the new sensor.
10 Install the new knock sensor into the engine block or intake manifold. Tighten it to 89 in-lbs. This torque is critical for the proper operation of the knock sensor.
11 Connect the electrical connector to the sensor.
12 Lower the vehicle.
Coolant Temperature Sensor (CTS)
Refer to illustration 11.13
General description
13 The CTS is a device that monitors the coolant temperature. It is
normally mounted in the thermostat housing (see illustration). As the
coolant temperature changes, the resistance of the sensor changes,
providing a varying input voltage to the computer. The computer uses
information from the CTS to adjust fuel/air mixture, ignition timing and
control EGR valve operation.
Check
14 Unplug the electrical connector from the sensor. Using an ohmmeter, check the resistance of the sensor with the engine cold - it should
be approximately 7000 ohms or greater. Start the engine and allow it
to reach normal operating temperature and recheck the resistance of
the sensor. It should now be less than 1000 ohms.
valve cover (see illustration 9.8). It is connected electrically to the
computer and by a vacuum hose to the throttle body. The MAP sensor
reads load (pressure) changes in the intake manifold. This causes
electrical resistance changes in the MAP sensor, resulting in changing
input voltage to the computer. The computer uses this information (input voltage) to vary the air/fuel mixture.
Check
18 Inspect the vacuum hose connections from the throttle body to the
MAP sensor. Replace a cracked or broken hose with a new one.
19 Disconnect the vacuum hose from the MAP sensor and connect a
hand vacuum pump. Apply vacuum. The sensor should hold vacuum.
If it does not, replace the sensor.
20 Using a high-impedance digital voltmeter, probe the A and B terminals (marked on the MAP sensor body) and make sure that, with the
ignition switch On and the engine Off, the voltage is between 4 and 5
volts. With the engine idling at normal operating temperature, the voltage should drop to around 2 volts. Check the voltage between the A
and C terminals with the ignition On and the engine Off. Voltage
should be approximately 5 volts. If the MAP sensor fails any of the
tests, replace it with a new one.
Replacement
21
22
23
24
25
Disconnect the electrical connector from the MAP sensor.
Detach the vacuum hose from the MAP sensor.
Remove the two mounting screws.
Remove the MAP sensor from the firewall.
Installation is the reverse of removal.
Manifold Air Temperature (MAT) sensor
General description
Refer to illustration 11.26
26 The MAT sensor is installed in the intake manifold (see illustration). Its sensor element extends into the air stream. The sensor resistance changes as the air stream temperature changes, sending a var-
Replacement
Warning: Wait until the engine is completely cool (at least five hours
after it has been run) before replacing the CTS.
15 Prepare the new sensor by wrapping the threads with Teflon tape
or applying a non-hardening thread sealant. Open the radiator cap to
release any residual pressure. Squeeze the upper radiator hose and
reinstall the cap (this will create a slight vacuum in the cooling system,
which will minimize coolant loss).
16 Disconnect the electrical connector from the sensor. Place rags
around the sensor to prevent spilling coolant. Unscrew the old sensor
and immediately install the new one as quickly as possible, tightening
it securely. Plug in the electrical connector. Check the coolant level
and add some, if necessary (see Chapter 1).
Manifold Absolute Pressure (MAP) sensor
General description
17 The MAP sensor is mounted on the firewall, near the rear of the
11.26 The Manifold Air Temperature (MAT) sensor (arrow)
6
The Motor Manual Guy
6-22
Chapter 6 Emissions and engine control systems
SEAL
RETAINER
11.42 The Crankshaft Position Sensor (CPS) is mounted in the
DISTANCE
SENSOR
transmission bellhousing
ADAPTER
SEAL
SPEEDOMETER
ADAPTER
11.52 Distance (speed) sensor installation details
ied input voltage to the computer. The computer uses this information
to alter the fuel/air mixture.
Check
27 Unplug the MAT sensor electrical connector and use a digital ohmmeter to check the sensor resistance. With the engine at normal operating temperature, the resistance of the sensor should be approximately 4000 ohms or less, decreasing as the air temperature in the
intake manifold rises.
Replacement
28
29
30
31
32
33
Remove the air cleaner (if necessary).
Disconnect the electrical connector from the MAT sensor.
Unscrew the MAT sensor from the intake manifold.
Clean the threaded hole to remove any corrosion or old sealant.
Wrap the threads of the new MAT sensor with Teflon tape.
Install the sensor in the manifold and tighten it securely.
Throttle Position Sensor (TPS)
General description
34 The Throttle Position Sensor, which is mounted on the side of the
throttle body and connected directly to the throttle shaft, senses throttle movement and position, then transmits an electrical signal to the
computer. This signal enables the computer to determine when the
throttle is closed, in its normal cruise condition or wide open.
Check
35 Unplug the TPS electrical connector. Using a high-impedance digital voltmeter, connect the positive probe to the center terminal and
the negative probe to each of the outside terminals (in turn). Note: This
is done by back probing the electrical connector (don't unplug the
connector from the TPS).
36 With the ignition On, slowly move the throttle lever until it is wide
open and observe the reading on the meter. With the throttle fully
closed it should read approximately 200 millivolts. With the throttle
fully open, it should be a little less than 4.8 volts. If the voltage readings are incorrect, replace the TPS.
Replacement
37 Detach the negative battery cable.
38 Unplug the electrical connector from the TPS.
39 Remove the screws and detach the TPS from the throttle body.
40 Position the new TPS on the throttle body, making sure the slot in
the TPS is aligned with the blade on the end of the throttle shaft.
41 Install the screws and tighten them securely. Note: The TPS on
1991 and later models is non-adjustable.
Crankshaft Position Sensor (CPS)
General description
Refer to illustration 11.42
42 The CPS, used on later fuel-injected models, is attached to the
transmission bellhousing (see illustration). The CPS detects teeth on
the flywheel as they pass the sensor during engine operation and provides the computer with information concerning engine speed and
crankshaft angle. This information is used to advance or retard ignition
timing and control fuel injector pulses.
Check
43 Disconnect the CPS electrical connector from the main wiring harness at the rear of the intake manifold.
44 If you're working on a 1991 or 1992 model, connect an ohmmeter
across terminals A and B (marked on the connector). The meter should
read no resistance (open).
45 If you're working on a 1993 model, Check the resistance between
the B and C terminals (marked on the connector. The meter should indicate no resistance (open).
46 If the readings are not to specification, replace the CPS.
Replacement
47 Disconnect the electrical connector from the CPS.
48 Detach the CPS by removing the two bolts.
49 Installation is the reverse of removal.
Distance sensor
Refer to illustration 11.52
General description
50 Some models are equipped with a distance sensor (instead of a
speedometer cable) that sends a pulsating voltage signal to the computer that the computer converts to miles per hour.
Check
51 A problem with this sensor would most likely cause a code 15 to
be stored in the computer's memory.
Replacement
52 To replace the distance sensor (located at the rear of the transfer
case), raise the vehicle, support it securely on jackstands, disconnect
the electrical connector from the sensor and unscrew it from the
speedometer adapter (see illustration). Installation is the reverse of
removal.
The Motor Manual Guy
Chapter 7 Part A
Manual transmission
Contents
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubricant change.
See Chapter
See Chapter
Lubricant level check.
Manual transmission shift lever - removal
and installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
1
1
Manual transmission overhaul
general information
Manual transmission
removal and installation
Oil seal replacement.
Transmission mount
check and replacement
6
5
2
4
3
Specifications
Torque specifications
Clutch housing-to-engine bolts (all models)
Shift lever cover retaining bolts
T4/5 transmission
AX 4/5 transmission
BA 10/1 5 transmission
1
Ft-lbs
28
13
13
17
General information
All vehicles covered in this manual come equipped with either a four
or five-speed manual transmission or an automatic transmission. All
information on the manual transmission is included in this Part of Chapter 7. Information on the automatic transmission can be found in Part
B of this Chapter.
Both four and five-speed manual transmissions are used in these
models. On five-speed transmissions, the 5th gear is an overdrive.
Due to the complexity, unavailability of replacement parts and the
special tools necessary, internal repair by the home mechanic is not
recommended. The information in this Chapter is limited to general information and removal and installation of the transmission.
Depending on the expense involved in having a faulty transmission
overhauled, it may be a good idea to replace the unit with either a new
or rebuilt one. Your local dealer or transmission shop should be able
to supply you with information concerning cost, availability and exchange policy. Regardless of how you decide to remedy a transmission
problem, you can still save a lot of money by removing and installing
the unit yourself.
ped) to the rear and remove it from the transmission. Be careful not
t o distort it.
5 Using a screwdriver or pry bar, carefully pry the oil seal out of the
rear of the transmission or transfer case. Do not damage the splines
on the transmission output shaft.
6 If the oil seal cannot be removed with a screwdriver or pry bar,
a special oil seal removal tool (available at auto parts stores) will be
required (see illustration).
7 Using a large section of pipe or a very large deep socket as a drift,
install the new oil seal. Drive it into the bore squarely and make sure
it's completely seated.
8 Reinstall the dust shield by carefully tapping it into place. Lubricate
the splines of the transmission output shaft and the outside of the
driveshaft sleeve yoke with lightweight grease, then install the driveshaft. Be careful not t o damage the lip of the new seal.
9 The speedometer cable and driven gear housing is located on the
side of the extension housing. Look for transmission oil around the cable
housing t o determine if the seal and O-ring are leaking.
SLIDE
HAMMER
2
Oil seal replacement
Refer to illustrations 2.6, 2.11, 21.13a and 2.13b
1 Oil leaks frequently occur due to wear of the extension housing
oil seal and/or the speedometer drive gear oil seal and O-ring. Replacement of these seals is relatively easy, since the repairs can usually be
performed without removing the transmission or transfer case (4WD
models) from the vehicle.
2 The extension housing oil seal is located at the extreme rear of
the transmission or transfer case, where the driveshaft is attached.
If leakage at the seal is suspected, raise the vehicle and support it
securely on jackstands. If the seal is leaking, transmission lubricant
will be built up on the front of the driveshaft and may be dripping from
the rear of the transmission or transfer case.
3 Refer t o Chapter 8 and remove the driveshaft.
4 Using a soft-faced hammer, carefully tap the dust shield (if equip-
2WD
EXTENSION HOUSING
2.6
On some models, a slide hammer with a special seal
puller may be required t o remove the oil seal
7A
The Motor Manual Guy
7A-2
Chapter 7 Part A
Manual transmission
2.1 1 Before loosening the retaining bolt, mark the
relationship between the speedometer adapter housing and
the transmission or transfer case with white paint - the
adapter is offset and must be installed in the same
relationship (retaining bolt shown removed for clarity)
2.13a
Use a small screwdriver t o remove the O-ring from
the groove, . . .
KNOB
2.13b . . . then lift the adapter seal
from the inside of the housing
3.2
Loosen the locknut, then remove
the shift knob
10 Disconnect the speedometer cable.
1 1 Mark the relationship of the speedometer adapter to the extension
housing (see illustration).
12 Remove the bolt and withdraw the adapter.
13 Install a new O-ring and adapter seal on the adapter and reinstall
the adapter and cable assembly on the extension housing (see illustrations).
3
3.3 Use a screwdriver t o detach the
bezel from the console, then lift
the boot off
\
Manual transmission shift lever - removal and installation
Refer to illustrations 3.2, 3.3, 3.5a and 3.5b
1 Place the shift lever in Neutral.
2 Loosen the locknut, then remove the shift knob (see illustration).
3 Use a screwdriver to disengage the boot retainer bezel from the
console, then lift off the boot (see illustration).
4 Remove the screws and lift out the center portion of the console.
5 Remove the five cover retaining bolts and lift the shift lever straight
up and out of the transmission (see illustrations). On some later models
it may also be necessary to remove a snap-ring and spring washer
before detaching the lever.
6 Installation is the reverse of removal. Tighten the shift lever cover
retaining bolts to the specified torque.
T 4 and T5 shift lever installation details
The Motor Manual Guy
Chapter 7 Part A
7A-3
Manual transmission
5
Manual transmission
removal and installation
Note: On 4 WD models, the transmission and transfer case are removed
as a unit.
Removal
DUST
'BOOT
COVER
.
UPPER
BUSHING
WASHER
LOWER---~
BUSHING
~
3.5b
4
AX 415 and BA 1015 shift lever installation details
transmission mount - check and replacement
Refer to illustration 4.2
1 Insert a large screwdriver or prybar into the space between the
transmission extension housing and the crossmember (2WD models)
or the transfer case and the crossmember (4WD models). Try to pry
the transmission or transfer case up slightly.
2 The transmission should not move away from the insulator much
at all (see illustration).
3 To replace the mount, remove the nuts attaching the insulator to
the crossmember and the bolts attaching the insulator to the transmission.
4 Raise the transmission or transfer case slightly with a jack and
remove the insulator, noting which holes are used in the crossmember
for proper alignment during installation.
5 Installation is the reverse of the removal procedure. Be sure to
tighten the nuts/bolts securely.
4.2
Pry on the transmission mount with a prybar or large
screwdriver to check for excessive looseness
1 Disconnect the negative cable from the battery.
2 Working inside the vehicle, remove the shift lever (see Section 3). On
4WD models, disconnect the transfer case shift linkage.
3 Raise the vehicle and support it securely on jackstands.
4 Disconnect the speedometer cable and wire harness connectors
from thetransmissionandtransfercase.Unbolttheclutch releasecvlinder
from theclutch housing (external cylinder) or disconnectthe hydraulic line
at the transmission (see Chapter 8).
5 Remove the driveshaft(s) (see Chapter 8). Use a plastic bag to cover
the end of the transmission to prevent fluid loss and contamination.
6 Removethe exhaust system components as necessary for clearance
(see Chapter 4).
7 Support the engine. This can be done from above with an engine
hoist, or by placing a jack (with a block of wood as an insulator) under the
engine oil pan. The engine should remain supported at all times while the
transmission is out of the vehicle.
8 Supportthe transmission with ajack-preferably a special jack made
for this purpose. Safety chains will help steady the transmission on the
jack. Warning: On 4WD models, do not attempt to remove the transmissionltransfer case assembly without a transmission jack and safety
chains. The assembly is very heavy and awkward to remove.
9 Remove the rear transmission (or transfer case) support-to-crossmember nuts and bolts.
10 Remove the nuts from the crossmember bolts. Raise the transmission slightly and remove the crossmember.
11 Remove the bolts securing the clutch housing to the engine.
12 Make a final check that all wires and hoses have been disconnected
from thetransmission and then movethetransmission and jacktoward the
rear of the vehicle until the transmission input shaft is clear of the clutch
housing. On 2WD models, keep the transmission level as this is done. On
some4WD models, the transmission/transfer case assembly is too long to
be removed with the engine level. You may need to lower the rear of the
engine to provide sufficient clearance for removal. The fan could contact
the shroud during this operation, so it is a good idea to place a block of
wood between the rear of the cylinder head(s) and the firewall to limit the
distance the rear of the engine drops.
13 Once the input shaft is clear, lower the transmission and remove it
from underthe vehicle. Caution: Donat depress the clutchpedal while the
transmission is out of the vehicle.
14 The clutch components can be inspected by removing the clutch
housing from the engine (see Chapter 8). In most cases, new clutch components should be routinely installed if the transmission is removed.
Installation
15 If removed, install the clutch components (see Chapter 8).
16 With the transmission secured to the jack as on removal, raise the
transmission into position behind the engine and then carefully slide it forward, engaging the input shaft with theclutch plate hub. Do not use excessive force to install the transmission - if the input shaft does not slide into
place, readjust the angle of the transmission so it is level and/or turn the
input shaft so the splines engage properly with the clutch.
17 Install the clutch housing-to-engine bolts. Tighten the bolts to the specified torque.
18 Install the crossmember and transmission support. Tighten all nuts
and bolts securely.
19 Remove the jacks supporting the transmission and the engine.
20 Install the various items removed previously, referring to Chapter 8
forthe installation of the driveshaft and Chapter 4 for information regarding
the exhaust system components. If the hydraulic line was disconnected,
bleed the clutch hydraulic system (see Chapter 8).
21 Make a final check that all wires, hoses and the speedometer cable
have been connected and that the transmission has been filled with lubricant to the proper level (see Chapter 1). Lower the vehicle.
22 Working inside the vehicle, install the shift lever (see Section 3).0n
4WD models, connect the transfer case shift linkage.
23 Connect the negative battery cable. Road test the vehicle for proper
operation and check for leakage.
7A
The Motor Manual Guy
7A-4
6
Chapter 7 Part A
Manual transmission overhaul - general information
Refer to illustrations 6.4a, 6.4b, 6.4c, 6.4d'6.4e, 6.4f and 6.49
Overhauling a manual transmission is a difficult job for the do-ityourselfer. It involves the disassembly and reassembly of many small
parts. Numerous clearances must be precisely measured and, if
necessary, changed with select fit spacers and snap-rings. As a result,
if transmission problems arise, it can be removed and installed by a
competent do-it-yourselfer, but overhaul should be left to a transmission
6.4a
1
2
3
4
Manual transmission
repair shop. Rebuilt transmissions may be available - check with your
dealer parts department and auto parts stores. A t any rate, the time
and money involved in an overhaul is almost sure to exceed the cost
of a rebuilt unit.
Nevertheless, it's not impossible for an inexperienced mechanic to
rebuild a transmission if the special tools are available and the job is
done in a deliberate step-by-step manner so nothing is overlooked.
The tools necessary for an overhaul include internal and external
snap-ring pliers, a bearing puller, a slide hammer, a set of pin punches,
a dial indicator and possibly a hydraulic press. In addition, a large, sturdy
workbench and a vise or transmission stand will be required.
T 4 manual transmission - exploded view
Transmission cover
Shift rail
1st-2nd gear shift fork
Selector plate
5 Selector arm interlock
plate and pin
6 3rd-4th gear shift fork
7 Plug
8 Thrust washer, rear
bearing and cup
9 1st gear
10 1st gear blocking ring
1 1 Output shaft
12 Reverse sliding gear
and insert springs
13 1st gear pin
14 Synchronizer insert
15 2nd gear blocking ring
16 2nd gear
17 Thrust washer
18 Snap-ring
19 3rd gear
2 0 3rd gear blocking ring
2 1 3rd-4rd gear synchronizer
spring, hub, insert
and sleeve
2 2 4th gear blocking ring
2 3 Needle thrust bearing
and race
2 4 Clutch shaft needle
roller bearing
2 5 Countershaft needle
thrust bearing
2 6 Countershaft rear bearing
27 Countershaft rear spacer
2 8 Countershaft gear
2 9 Countershaft front
thrust washer
3 0 Countershaft front bearing
3 1 Offset lever
3 2 Damper sleeve
3 3 Roll pin
3 4 Detent spring
3 5 Detent ball
36 Adapter housing
37 Identification tag
3 8 Adapter housing seal
3 9 Vent
4 0 Reverse idler gear shaft
41 Roll pin
4 2 Reverse idler gear
4 3 Bushing
44 Reverse gear lever fork
4 5 Reverse gear lever
pivot pin bolt
46 Back-up light switch
4 7 Drain plug
4 8 Transmission case
4 9 Clutch shaft
5 0 Front bearing
Front bearing race
5 2 Shim
5 3 Oil seal
5 4 Front bearing cap
The Motor Manual Guy
Chapter 7 Part A
During disassembly of the transmission, make careful notes of how
each piece comes off, where it fits in relation to other pieces and what
holds it in place. Exploded views are included (see illustrations)to show
where the parts go - but actually noting how they are installed when
you remove the parts will make it much easier to get the transmission
back together.
Manual transmission
7A-5
Before taking the transmission apart for repair, it will help if you have
some idea what area of the transmission is malfunctioning. Certain
problems can be closely tied to specific areas in the transmission, which
can make component examination and replacement easier. Refer t o
the Troubleshooting section at the front of this manual for information
regarding possible sources of trouble.
6.4b T5 Manual transmission - exploded view
I
2
3
4
5
O-ring
Transmission cover
Shift rail
1st-2nd gear shift fork
Selector plate
6 Selector arm, interlock
plate and pin
7 3rd-4th gear shift fork
8 Plug
9 Snap-ring
10 5th driven gear
1 Thrust washer, rear
bearing and cup
12 1stgear
13 1st gear blocking ring
14 Output shaft
15 Re verse sliding gear
and insert springs
16 Roll pin
17 Synchronizer insert
18 2nd gear blocking ring
19 2nd gear and thrust washer
2 0 Snap-ring
2 1 3rd gear
22 3rd gear blocking ring
2 3 3rd-4th gear synchronizer
springs, hub, insert
and sleeve
24 4th gear blocking ring
25 Needle thrust bearing
and race
26 Clutch shaft needle
roller bearing
2 7 Funnel
2 8 Snap-ring
29 Thrust bearing race
30 Countershaft needle thrust
bearing and race
3 1 Insert retainer
32 5th gear synchronizer sleeve
and insert springs
3 3 5th gear synchronizer insert,
hub and blocking ring
34 5th gear
35 Snap-ring and spacer
36 Countershaft rear bearing
and spacer
37 Countershaft gear
38 Countershaft front bearing
and thrust washer
39 Offset lever
4 0 Damper sleeve
4 1 Detent spring and ball
42 Identification tag
43 Adapter housing seal
4 4 Adapter housing
4 5 Vent
46 Roll pin
4 7 5th gear shift fork
4 8 5th gear and reverse gear rail
4 9 5th gear and reverse gear
shift lever
5 0 Roll pin
51 Reverse idler gear, bushing
and shaft
52 5th gear lever pivot pin bolt
and back-up light switch
5 3 Transmission case
5 4 Drain plug
55 Clutch shaft
56 Front bearing
57 Front bearing cap oil
seal, shim and race
5 8 Front bearing cap
·1A . .
The Motor Manual Guy
7A-6
6.4c AX 4/5 Manual transmission - exploded view
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
cfk,o
C:[email protected]=}"
11--
Shift lever
Shift lever retainer
Restrict pins
Front bearing retainer
Clutch housing
Snap-ring
Back-up light switch
Intermediate plate
Adapter housing
Adapter sere w plug
Output shaft
Reverse idler gear
lnput shaft
Counter gear
Straight sere w plug
Spring
Locking ball
13
5
14
4
f j
@(y)
'
6
6.4d AX 415 manual transmission output shaft, counter.
shaft and synchronizer exploded view
Output shaft
Snap-ring
Snap-ring
5th gear
Rear bearing
retainer
6 Synchronizer ring
4th gear
7 lnput shaft
8 Counter gear
9 Counter rear bearing
10 Snap-ring
11 Spacer
12 Needle roller bearino 5th
13 Counter 5th gear
14 Hub sleeve no. 3
15 Synchronizer ring 5th gear
Gear spline piece no.5
16
l
7
2
3
4
5
12
The Motor Manual Guy
,_---------------------------1A-7
5
7
6
I_ -
-
-
9
8
-
10
AX 4/5 manual transmission output
shaft
exploded view
6.4e
1
2
3
4
5
6
7
Rear bearing
Inner race
1st gear needle roller bearing
1st gear
1st gear synchronizer ring
Hub sleeve no. 1
2nd gear synchronizer ring
8
9
10
I1
12
13
14
2nd gear
2nd gear needle roller bearing
Output shaft
3rd gear
3rd gear synchronizer ring
Hub sleeve no. 2
Snap-ring
7A
AX 5 manual transmission shift
components - exploded view
6.4f
2
3
4
5
6
7
Shift lever shaft
Shift lever housing
Reverse restrict pin
Shift fork shaft no. 2
Shift fork no. 2
Shift fork no. I
Shift fork shaft no. 1
8 Shift fork shaft no. 3
9 Shift fork shaft no. 4
10 Reverse shift arm bracket
11 Shift fork no. 3
12 Reverse shift arm and fork
13 Shift fork shaft no. 5
14 Reverse shift head
The Motor Manual Guy
7A-8
BA
manual transmission - exploded view
5th gear lock ring
5th gear roller bearing
5th gear
5th gear snap-ring
Reverse gear nut
Washer (not used in
all models)
7 Reverse gear
8 Rear bearing retainer
9 Rear bearing race
10 Rear bearing
11 Rear bearing shirn
12 Shim washer
13 1stgear bearing
14 Bearing spacer
15 1stgear
16 1st-2ndsynchronizer
7 7 Synchronizer hub
18 2nd gear bearing
19 2nd gear
2 0 Mainshaft
2 7 3rd gear bearing
22 3rd gear
2 3 3rd-4th synchronizer
24 Synchronizer hub
2 5 Spring washer
26 Lock ring
2
3
4
5
6
27
28
29
30
31
32
33
34
35
36
37
38
39
40
4
42
43
44
45
46
47
Pilot bearing shims
Pilot bearing
Pilot bearing race
Input shaft
Front bearing
Front bearing race
Front bearing shims
Front bearing retainer
Oil seal
Mounting studs
Bearing race
Cluster front bearing
Front bearing shirn
Cluster gear
Cluster rear bearing
Bearing race
lntermediate shaft
Synchronizer hub
5th gear synchronizer
5th intermediate gear
5th intermediate gear
bearing
4 8 Thrust washer
49 End play shim
50 lntermediate shaft roller
bearing race
51 Oil seal
52 Rear case
5 3 5th gear roller bearing race
5 4 Snap-ring
5 5 lntermediate shaft
roller bearing
56 Alignment dowels
57 1st-2ndlock spring and ball
58 Roll pin
5 9 Idler shaft
60 Reverse idler gear
6 1 Roll pin
62 5th-Reverse shift fork
6 3 5th-reverse shift rail
6 4 1st-2nd shift rail
6 5 Roll pin
66 1st-2nd shift fork
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Roll pin
3rd-4th shift fork
3rd-4th shift rail lock pin
3rd-4th shift rail
Detent plug
1st-2nddetent spring
1st-2nd detent ball
Interlock ball
Lock finger
Back-up light switch
and washer
Alignment dowels
Front case
left half
Detent plug
5th-Reverse detent spring
5th-Reverse detent ball
Front case - right half
Intermediate case
Fill plug and washer
Drain plug and washer
Access plug
The Motor Manual Guy
Chapter 7 Part B
Automatic transmission
Contents
Automatic transmission
removal and installation
Bands
adjustment (three-speed transmission)
Diagnosis
general.
Fluid and filter change
Fluid level check
General information
Neutral start switch check.
Neutral start switch - check, adjustment
and replacement
Oil seal replacement
Shift linkage
check and adjustment.
Throttle valve (TV) linkage
adjustment
Transmission mount
check
and replacment
7
5
2
See Chapter 1
See Chapter 1
1
See Chapter 1
6
See Chapter 7A
3
4
See Chapter 7A
Specifications
Torque specifications
Transmission housing-to-engine bolts
Torque converter-to-driveplate bolts
Three-speed transmission front band
Adjusting screw (with adapter)
Adjusting screw (without adapter)
Locknut
Three-speed transmission rear band
Adjusting screw
Locknut
Neutral start switch
Three-speed
Four-speed
Adjusting bolt
Attaching nut
Transmission pan bolts
1
General information
All vehicles covered in this manual come equipped with a four or
five-speed manual transmission or a three or four-speed automatic
transmission. All information on the automatic transmission is included
Ft-lbs (unless otherwise indicated)
30
40
3 6 in-lbs
72 in-lbs
30
41 in-lbs
35
24
9
5
10
in this Part of Chapter 7, Information on the manual transmission can
be found in Part A of this Chapter.
Due to the complexity of the automatic transmissions covered in
this manual and the need for specialized equipment to perform most
service operations, this Chapter contains only general diagnosis, routine
7B
The Motor Manual Guy
7B-2
Chapter 7 Part B
Automatic transmission
maintenance, adjustment and removal and installation procedures.
If the transmission requires major repair work, it should be left to
a dealer service department or an automotive or transmission repair
shop. You can, however, remove and install the transmission yourself
and save the expense, even if the repair work is done by a transmission
shop.
2 Diagnosis - general
Note: Automatic transmission malfunctions may be caused b y five
general conditions: poor engine performance, improper adjustments,
hydraulic malfunctions, mechanical malfunctions or malfunctions i n
the computer or its signal network. Diagnosis o f these problems should
always begin with a check o f the easily repaired items: fluidlevel and
condition (Chapter 1), shift linkage adjustment and throttle linkage adjustment. Next, perform a road test to determine if the problem has
been corrected or if more diagnosis is necessary. If the problem persists
after the preliminary tests and corrections are completed, additional
diagnosis should be done b y a dealer service department or transmission
repair shop. Refer to the Troubleshooting Section at the front o f this
manual for information on symptoms o f transmission problems.
Preliminary checks
1 Drive the vehicle to warm the transmission t o normal operating
temperature.
2 Check the fluid level as described in Chapter 1:
a) If the fluid level is unusually low, add enough fluid to bring the
level within the designated area of the dipstick, then check for
external leaks (see below).
b) If the fluid level is abnormally high, drain off the excess, then
check the drained fluid for contamination by coolant. The
presence of engine coolant in the automatic transmission fluid
indicates that a failure has occurred in the internal radiator walls
that separate the coolant from the transmission fluid (see Chapter
3).
c) If the fluid is foaming, drain it and refill the transmission, then
check for coolant in the fluid or a high fluid level.
3 Check the engine idle speed. Note: If the engine is malfunctioning,
do not proceed with the preliminary checks until it has been repaired
and runs normally.
4 Check the throttle valve linkage for freedom of movement. Adjust
it if necessary (Section 4). Note: The throttle valve linkage may function
properly when the engine is shut o f f and cold, b u t i t may malfunction
once the engine is hot. Check it cold and a t normal engine operating
temperature.
5 Inspect the shift control linkage (see Section 3). Make sure it's
properly adjusted and the linkage operates smoothly.
Fluid leak diagnosis
6 Most fluid leaks are easy to locate visually. Repair usually consists
of replacing a seal or gasket. If a leak is difficult to find, the following
procedure may help.
7 Identify the fluid. Make sure it's transmission fluid and not engine
oil or brake fluid (automatic transmission fluid is a deep red color).
8 Try to pinpoint the source of the leak. Drive the vehicle several
miles, then park it over a large sheet of cardboard. After a minute or
two, you should be able to locate the leak by determining the source
of the fluid dripping onto the cardboard.
9 Make a careful visual inspection of the suspected component and
the area immediately around it. Pay particular attention to gasket mating
surfaces. A mirror is often helpful for finding leaks in areas that are
hard to see.
10 If the leak still cannot be found, clean the suspected area thoroughly
with a degreaser or solvent, then dry it.
11 Drive the vehicle several miles at normal operating temperature
and varying speeds. After driving the vehicle, visually inspect the
suspected component again.
12 Once the leak has been located, the cause must be determined
before it can be properly repaired. If a gasket is replaced but the sealing
flange is bent, the new gasket will not stop the leak. The bent flange
must be straightened.
13 Before attempting to repair a leak, check to make sure the following
conditions are corrected or they may cause another leak. Note: Some
o f the following conditions cannot be fixed without highly specialized
tools and expertise. Such problems must be referred to a transmission
repair shop or a dealer service department.
Gasket leaks
1 4 Check the pan periodically. Make sure the bolts are tight, no bolts
are missing, the gasket is in good condition and the pan is flat (dents
in the pan may indicate damage to the valve body inside).
1 5 If the pan gasket is leaking, the fluid level or the fluid pressure may
be too high, the vent may be plugged, the pan bolts may be too tight,
the pan sealing flange may be warped, the sealing surface of the transmission housing may be damaged, the gasket may be damaged or the
transmission casting may be cracked or porous. If sealant instead of
gasket material has been used to form a seal between the pan and the
transmission housing, it may be the wrong sealant.
Seal leaks
16 If a transmission seal is leaking, the fluid level or pressure may
be too high, the vent may be plugged, the seal bore may be damaged,
the seal itself may be damaged or improperly installed, the surface of
the shaft protruding through the seal may be damaged or a loose bearing
may be causing excessive shaft movement.
17 Make sure the dipstick tube seal is in good condition and the tube
is properly seated. Periodically check the area around the speedometer
gear or sensor for leakage. If transmission fluid is evident, check the
O-ring for damage.
Case leaks
1 8 If the case itself appears t o be leaking, the casting is porous and
will have to be repaired or replaced.
19 Make sure the oil cooler hose fittings are tight and in good
condition.
Fluid comes out the vent pipe or fill tube
2 0 If this condition occurs, the transmission is overfilled, there is
coolant in the fluid, the case is porous, the dipstick is incorrect, the
vent is plugged or the drain back holes are plugged.
3
Shift linkage - check and adjustment
Refer to illustrations 3.3 and 3.4
Check
1 Firmly apply the parking brake and try to momentarily operate the
starter in each shift lever position. The starter should operate in Park
and Neutral only. If the starter operates in any position other than Park
or Neutral, adjust the shift linkage (see below). If, after adjustment,
the starter still operates in positions other than Park or Neutral, the
neutral start switch is defective or in need of adjustment (see Section 6).
Adjustment
2 Place the shift lever in Park. Raise the vehicle and support it securely
on jackstands.
3 On three-speed transmissions, loosen the shift rod jam nut, remove
the lockpin and disengage the trunnion and shift rod at the bellcrank
(see illustration).
4 On four-speed transmissions, release the adjuster clamp to unlock
the shift cable, then unsnap the shift cable from the cable bracket (see
illustration).
5 Be sure the shift lever on the transmission is all the way t o the
rear, in the last detent. This is the Park position.
6 Make sure the park lock is engaged by trying t o rotate the
driveshaft. The driveshaft will not rotate if the park lock is functioning
properly.
7 On three-speed transmissions, slide the shift rod trunnion forward
or backward in the shift rod slot, as necessary, so the pin fits freely
in the bellcrank arm. Tighten the jam nut securely while holding the
shift rod so it doesn't turn as the jam nut is tightened. When properly
adjusted, there should be no lash in the shift linkage. Pull down on
the shift rod while pushing up on the outer part of the bellcrank to
eliminate lash.
8 On four-speed transmissions, snap the shift cable into the bracket.
then press down on the adjuster clamp until it snaps in place to lock
the shift cable.
9 Lower the vehicle.
1 0 With the parking brake firmly applied, make sure the engine starts
only in Park and Neutral. If the linkage appears to be adjusted properly,
The Motor Manual Guy
Chapter 7 Part B
7B-3
Automatic transmission
,•
•'
CLAMP
1
3.3
3 Shift rod
4 Bellcrank
but the starter operates in positions other than Park or Neutral, check
the neutral start switch (see Section 6).
1 1 Check the steering wheel lock to make sure it operates smoothly.
4
Throttle valve (TV) linkage
- adjustment
1 The throttle linkage on these models can be adjusted to correct
harsh, delayed or erratic shifting and lack of kickdown.
3-speed transmission
Four-cylinder engine (carburetor equipped models only)
Refer to illustrations 4.3 and 4.5
Note: On four-c ylinder fuel injected models, TV linkage adjustment requires special equipment. The job should be left to a dealer service
department repair shop.
,
CABLE
-~RACKET
TRANSMISSION
SHIFT
LEVER
Three-speed transmission shift linkage
I Jam nut
2 Trunnion
\
3.4 Four-speed transmission shift linkage
2
Remove the air cleaner assembly, then remove the spark plug wire
separator from the throttle bracket and secure it out of the way.
3 From under the vehicle, hold the throttle control lever all the way
forward, against the stop, and secure it with a spring (see illustration).
4 In the engine compartment, block the throttle open and set the
carburetor linkage completely off the fast idle cam. On air conditioning
equipped models, turn the ignition switch on to energize the throttle
stop solenoid.
5 Loosen the adjusting link bolt (see illustration).
6 Remove the load on the throttle valve linkage by pulling on the
link and tightening the link bolt.
7 Turn the ignition off, install the spark plug wires and separator,
connect the throttle stop solenoid on air conditioned models, install
the air cleaner and remove the spring from the throttle control lever.
Test drive the vehicle and check for proper shifting operation, readjusting as necessary.
78
4.3 On four-cylinder carburetor equipped models, hook
one end of the TV linkage return spring (A) over the end of
the throttle control lever (8) and the other end through the
hole i n the bellhousing boss (C)
4.5
Use a box end wrench to loosen the adjusting link
bolt (arrow)
The Motor Manual Guy
Chapter 7 Part B
7B-4
Automatic transmission
THROTTLE
ROD
I
STOP
LINK
4.8
CLAMP
BOLT
RETAINER
BOLT
V6 engine TV rod adjustment link details
V6 engine
Refer to illustrations 4.8 and 4.12
8 Remove the throttle control rod spring. Use the spring to hold the
adjusting link against the nylon stop, in the forward position (see
illustration).
9 Block the choke open and set the throttle off the fast idle cam.
On models equipped with a throttle-operated solenoid valve, turn the
ignition switch on, to energize the solenoid, and open the throttle halfway to lock it. Return the throttle to the idle position.
10 Raise the vehicle and support it securely with jackstands.
1 1 Loosen the retainer and clamp bolts on the throttle control adjusting
link (see illustration 4.8).
12 Use a spare spring to hold the transmission throttle valve lever all
the way forward, against the stop (see illustration). Hook the spring
to the torque converter boss.
13 Push on the end of the link to eliminate any lash, pull the clamp
fHROTTLE
VALVE
SPRING
4.12
Secure the TV lever in the forward position using a
spare return spring (V6 models)
to the rear so the bolt bottoms in the rear of the rod slot. Tighten the
clamp bolt. Pull the throttle control rod t o the rear until the rod bolt
bottoms in the front rod slot and tighten the retainer bolt.
14 Install the throttle control rod spring, remove the spring from the
transmission lever and lower the vehicle.
Four-speed transmission
Refer to illustrations 4.15 and 4.16
15 With the ignition switch in the Off position, retract the cable adjuster by depressing the button, then pushing the plunger in (see
illustration).
16 Rotate the throttle lever on the fuel injection unit to the wide open
throttle position (see illustration).
17 Hold the throttle lever open and allow the cable plunger (see illustration 4.15) to extend all the way, which automatically adjusts the
cable. Once the plunger is fully extended, release the throttle lever.
FOUR-CYLINDER
ENGINE
V6 AND
INLINE
V
l·_____
4.15
SIX-CYLINDER
ENGINES
__JI
To retract the cable adjuster
press the button
4.16 Rotate the fuel injection throttle lever to the wide
(Bl, then push the cable plunger
(C) in
open throttle
position _
(A), _
_ _ _ _
_
The Motor Manual Guy
Chapter 7 Part B
ADJUSTING
SCREW
Automatic transmission
78-5
ADAPTER
, EXTENSION
IN-LB
TORQUE
,WRENCH
5.8
5.5
5
An adapter extension and inch-pound torque wrench
are required to adjust the front transmission band
Bands
adjustment (three-speed transmission)
Refer to illustrations 5.5 and 5.8
1 The transmission bands should be adjusted at the specified intervals or when the automatic upshifts or downshifts become consistently
harsh and/or erratic.
2 Raise the vehicle and support it on jackstands.
Front band
3
The front band adjusting screw is located on the left side of the
transmission, just above the throttle valve control levers.
4 Loosen the adjusting screw locknut and back it off five turns. Check
the adjusting screw to make sure it turns freely in the case, lubricating
it if necessary.
5 Using an in-lb torque wrench, adapter extension and a 5/16-inch
socket, tighten the adjusting screw to the specified torque (see illustration). If the adapter tool is not used, the alternate torque must be used.
6 Back the screw off t w o full turns.
7 Tighten the adjusting screw locknut to the specified torque while
holding the screw with a socket or wrench so it does not rotate.
The rear band adjusting screw is accessible after
removing the transmission pan
unit. The switch has three terminals with the neutral switch being the
center one. A ground for the starter solenoid circuit is provided through
the gearshift lever in only the Neutral and Park positions.
2 Raise the vehicle and place it securely on jackstands. Remove the
wiring connector from the neutral switch (see illustration) and test the
switch for continuity. Continuity should exist between the center terminal and transmission case only when the gearshift is in Neutral and
Park. If the switch appears to be faulty, check the shift linkage (see
Section 3) before replacing the switch.
3 Prior to replacing the switch, place a container under i t to catch
the transmission fluid.
4 Remove the switch and allow the fluid t o drain into the container.
5 Place the gearshift lever in Park and Neutral and check the lever
finger position and lever and shaft alignment with the switch opening.
6 Install the switch and seal, tightening the bolts to the specified
torque.
7 Test the switch for continuity and plug in the connector.
8 Lower the vehicle and check the transmission fluid level (see
Chapter 1 ), adding the specified fluid as necessary.
NEUTRAL
CONTACT,
7B
Rear band
8 The rear band adjusting screw is accessible after removing the oil
pan (see illustration). Consequently, it's very convenient t o make this
adjustment at the time of the transmission fluid and filter change (see
Chapter 1).
9 Remove the oil pan.
1 0 Loosen the adjusting screw locknut.
11 Tighten the adjusting screw with an in-lb torque wrench and
a 114-inch socket to the specified torque.
12 Back the adjusting screw out seven full turns.
13 Install the locknut, hold the screw with a socket or wrench so i t
cannot turn and tighten the locknut to the specified torque.
1 4 Install the transmission pan and lower the vehicle.
LEVER
NEUTRAL
SWITCH
6
Neutral start switch - check, adjustment and replacement
Three-speed transmission
Refer to illustration 6.2
1 The neutral start and back-up light switches are combined into one
PARK
CONTACT
6.2 The neutral start switch on the three-speed
transmission screws into the housing and contacts the
internal shift lever (transmission pan removed for clarity)
The Motor Manual Guy
Chapter 7 Part B
7B-6
Automatic transmission
SWITCH
TERMINAL
IDENTIFICATION
TABBED
WASHER
NEUTRAL~.
1
SWITCH
~~~~,,__
=\~1~
B
p
~
C
A
G
H
-v
-
R
N
E
0-
D
3
-
1-2
6.9 The terminals for the four-speed transmission neutral start
the chart shows when
switch connector are shown above
continuity should exist between the terminals: when i n Park or
Neutral, continuity should exist between B and C; when in
Reverse, between A and E; when in 3rd. between A and G;
when i n 1st or 2nd. between A and H
Four-speed transmission
Refer to illustrations 6.9, 6. 10 and 6. 13
9 Raise the vehicle and place it securely on jackstands. Unplug the
connector and check for continuity, referring to the accompanying illustration. Replace the switch if continuity is not as specified.
1 0 To replace the switch, unplug the connector, pry up the washer
tabs and remove the attaching nut and adjusting bolt (see illustration).
Lift the switch off the shaft.
11 Disconnect the shift linkage on the left side of the transmission
and rotate the shift lever all the way to the rear (Park), then t w o detent
positions forward to Neutral.
12 Place the switch in position and install the nut and bolt finger tight.
Tighten the attaching nut to the specified torque but do not bend the
tabs down.
13 Make sure the transmission is in Neutral and rotate the switch until
the neutral standard line on the housing lines up with the vertical groove
in the manual valve shaft (see illustration). Tighten the adjusting bolt
to the specified torque and bend the washer tabs over the attaching nut.
14 Plug in the electrical connector, connect the shift linkage, lower
the vehicle and check the switch operation t o make sure the starter
operates in Park or Neutral only. Be sure to firmly apply the parking
brake when making this check.
7
Automatic transmission
- removal and installation
Note: On 4WD models, the transmission and transfer case are removed
together, as an assembly.
Removal
1
2
3
4
Disconnect the negative cable from the battery.
Raise the vehicle and support it securely on jackstands.
Drain the transmission fluid (see Chapter 1 ), then reinstall the pan.
Remove the torque converter cover.
5 Mark the relationship of the torque converter to the driveplate with
white paint so they can be installed in the same position.
6 Remove the torque converter-to-driveplate bolts. Turn the crankshaft for access to each bolt. Turn the crankshaft in a clockwise direction only (as viewed from the front).
7 Remove the starter motor (see Chapter 5).
8 Remove the driveshaft(s) (see Chapter 8).
9 Disconnect the speedometer cable.
ATTACHING
NUT
6.10
Four-speed neutral start switch mounting details
NEUTRAL
STANDARD LINE
ADJUSTING
BOLT
VERTICAL
GROOVE
ON MANUAL
VALVE SHAFT
6.13 With the transmission in Neutral, the neutral
standard line on the switch must be aligned with the
vertical groove in the manual valve shaft
1 0 Detach the wire harness connectors from the transmission.
11 On models so equipped, disconnect the vacuum hoses.
12 Remove any exhaust components which will interfere with transmission removal (see Chapter 4).
13 Disconnect the TV linkage rod or cable.
1 4 Disconnect the shift linkage. On 4WD models, also disconnect the
transfer case shift linkage.
1 5 Support the engine with a jack. Use a block of wood under the
oil pan to spread the load.
16 Support the transmission and transfer case (4WD models) with
a jack - preferably a jack made for this purpose. Safety chains will
help steady the transmission on the jack. Warning: On 4WD models,
you must use safety chains because the transmission and transfer case
assembly is very heavy and awkward to remove.
17 Remove the rear mount-to-crossmember bolts.
18 Raise the transmission and transfer case (4WD models) slightly,
then remove the four crossmember-to-frame bolts and detach the crossmember.
19 Remove the bolts securing the transmission to the engine.
The Motor Manual Guy
Chapter 7 Part B
2 0 Lower the transmission slightly and disconnect and plug the transmission fluid cooler lines.
21 Remove the transmission dipstick tube.
22 Move the transmission to the rear to disengage it from the engine
block dowel pins and make sure the torque converter is detached from
the driveplate. Secure the torque converter to the transmission so it
won't fall out during removal.
Installation
23 Prior to installation, make sure the torque converter hub is securely
engaged in the pump.
2 4 With the transmission and transfer case (4WD models) secured
to the jack, raise it into position. Be sure to keep it level so the torque
converter does not slide forward. Connect the transmission fluid cooler
lines.
25 Turn the torque converter t o line up its bolt holes with the holes
in the driveplate. The white paint mark on the torque converter and
the driveplate made in Step 5 must line up.
26 Move the transmission and transfer case (4WD models) forward
carefully until the dowel pins and the torque converter are engaged.
27 lnstall the transmission housing-to-engine bolts. Tighten them to
the specified torque.
Automatic transmission
7B-7
the specified torque.
28 lnstall the torque converter-to-driveplate bolts. Tighten the bolts
to the specified torque.
29 lnstall the rear mount-to-crossmember and crossmember-to-frame
bolts. Tighten the bolts securely.
3 0 Remove the jacks supporting the transmission and transfer case
(4WD models) and the engine.
31 lnstall the dipstick tube.
3 2 lnstall the starter motor (see Chapter 5).
3 3 Connect the vacuum hose(s) (if equipped).
3 4 Connect the shift and TV linkage. On 4WD models, connect the
transfer case shift linkage.
3 5 Plug in the transmission wire harness connectors.
3 6 lnstall the torque converter cover.
3 7 lnstall the driveshaft(s).
3 8 Connect the speedometer cable.
39 Adjust the shift linkage.
4 0 lnstall any exhaust system components that were removed or
disconnected.
4 1 Lower the vehicle.
42 Fill the transmission with the specified fluid (see Chapter 1 ), run
the engine and check for fluid leaks.
7B
The Motor Manual Guy
Chapter 7 Part C
Transfer case
Contents
General information
Oil seal replacement
Shift linkage adjustment . . . . . . . .
Transfer case lubricant change
Transfer case lubricant level check
...........
1
See Chapter 7 A
......... 2
See Chapter 1
See Chapter 1
Transfer case overhaul
general information
Transfer case
removal and installation
Transmission mount
check
and replacement . . . . . . . . . . . . . . . . . . . . .
Specifications
Torque specifications
Transfer case-to-transmission nuts . . . . . . . . . . . . . . . . . . . .
Universal joint flange nut . . . . . . . . . . . . . . . . . . . . . . . . . . .
Universal joint strap-to-transfer case yoke bolts
Rear crossmember-to-chassis sill bolts
Transmission support-to-crossmember nuts
Ft-lbs
30
35
14
30
33
4
3
. . See Chapter 7A
The Motor Manual Guy
Chapter 7 Part C
1
General information
The transfer case is a device which passes the power from the engine
and transmisssion to the front and rear driveshafts.
Several transfer cases were used on these models: New process
2071231 (Command Trac) and 22812291242 (Selec-Trac). CommandTrac is a part-time transfer case with three operating ranges: 2WD high,
4WD high (full-time 4WD) 4WD high lock (part-time 4WD) and 4WD
low lock (part-time 4WD).
2 Shift linkage adjustment
Refer
to illustrations 2.2 and 2.4
1 Remove the shift lever boot or move the carpeting aside for access
to the lever.
2 Position the shift lever as far t o the rear as possible and insert a
118-inch thick shim between the shift lever and the shift gate (see
illustration).
3 Raise the vehicle and support it securely on jackstands.
4 Under the vehicle, loosen the shift linkage trunnion lock bolt and
make sure the shift rod fits freely in the trunnion and shift lever (see
illustration). Tighten the bolt securely.
5 Lower the vehicle, remove the shim and reinstall any components
which were removed.
3 Transfer case - removal and installation
Removal
1
2
Disconnect the negative cable from the battery.
Raise the vehicle and support it securely on jackstands.
3 Drain the transfer case lubricant (see Chapter 1 ).
4 Disconnect the speedometer cable, shift lever, vacuumlvent lines
and wire harness connectors from the transfer case.
5 Remove the driveshafts (see Chapter 8).
6 Remove the exhaust system components as necessary for
clearance (see Chapter 4).
Transfer case
7C-1
7 Support the transmission with a jack or jackstand. The transmission
should remain supported at all times while the transfer case is out of
the vehicle.
preferably a special jack
8 Support the transfer case with a jack
made for this purpose. Safety chains will help steady the transfer case
on the jack.
9 Remove the rear transmission support-to-crossmember nuts and
bolts.
1 0 Remove the crossmember bolts. Raise the transfer case slightly
and remove the crossmember.
11 Remove the nuts securing the transmission to the transfer case.
Lower the transmission sufficienty to allow access to the upper nuts.
12 Make a final check that all wires and hoses have been disconnected
from the transfer case and then move the transfer case and jack toward
the rear of the vehicle until the transfer case is clear of the transmission.
Keep the transfer case level as this is done.
1 3 Once the input shaft is clear, lower the transfer case and remove
it from under the vehicle.
Installation
14 With the transfer case secured to the jack as on removal, raise
it into position behind the transmission and then carefully slide it for-
ward, engaging the input shaft with the transmission output shaft. Do
not use excessive force to install the transfer case
if the input shaft
does not slide into place, readjust the angle so it is level and/or turn
the input shaft so the splines engage properly with the transmission.
15 Install the transmission-to-transfer case nuts. Tighten the nuts to
the specified torque.
16 Install the crossmember and transmission support. Tighten all nuts
and bolts securely.
17 Remove the jacks supporting the transmission and the transfer
case.
18 Install the various items removed previously, referring to Chapter 8
for the installation of the driveshafts and Chapter 4 for information
regarding the exhaust system components.
19 Make a final check that all wires, hoses and the speedometer cable
have been connected and that the transmission has been filled with
lubricant to the proper level (see Chapter 1 ). Lower the vehicle.
2 0 Connect the negative battery cable. Road test the vehicle for proper
operation and check for leakage.
7C
2.2 Pull the shift lever (Al back and insert the shim (Bl
between the lever and the shift gate (C}
2.4 Loosen the lock bolt (Dl on the trunnion (E} and adjust the
rod (Fl so it fits freely in the trunnion and the shift lever (G}
The Motor Manual Guy
Chapter 7 Part C
7C-2
4
Transfer case overhaul - general information
Refer to illustrations 4.4a, 4.4b'4.4c, 4.4d and 4.4e
Overhauling a transfer case is a difficult job for the do-it-yourselfer.
It involves the disassembly and reassembly of many small parts.
Transfer case
Numerous clearances must be precisely measured and, if necessary,
changed with select fit spacers and snap-rings. As a result, if transfer
case problems arise, it can be removed and installed by a competent
do-it-yourselfer, but overhaul should be left to a transmission repair
shop. Rebuilt transfer cases may be available - check with your dealer
4.4a Typical Command- Trac transfer case
(New Process 207) - exploded view
1
2
3
4
5
6
7
8
9
10
I1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Main driveshaft
Case housing
Oil pump housing seal
Oil pump housing
Oil pump
Speedometer drive gear
Mainshaft rear
bearing retainer
Case vent connector
Bolt
Mainshaft rear bearing
Mainshaft rear bearing
retaining ring
Mainshaft extension
Hex bolt
Case mainshaft
extension bushing
Mainshaft extension seal
Case oil plug
Hex bolt
Housing alignment
do we! washer
Housing alignment do we!
Front output shaft
pilot bearing
Front output shaft
Planet gear assembly carrier
Planet gear carrier retaining
ring thrust washer
Planet gear carrier
retaining ring
Planet gear carrier
annulus gear
Main driveshaft synchronizer
retainer ring
Main driveshaft assembly
synchronizer
Synchronizer strut
Synchronizer strut spring
Synchronizer stop ring
Drive chain sprocket bearing
Drive chain sprocket
Drive chain sprocket
thrust washer
lnput main drive gear
thrust washer
lnput drive gear pilot bearing
Cup plug
lnput main drive
assembly gear
lnput drive gear thrust
lnput drive gear thrust
bearing washer
Low range lock plate
Vacuum four wheeldrive
switch
Four wheel drive indicator
light switch seal
Oil access hole plug
Case housing (front half)
45
drive bearing
4 6 lnput drive gear seal
4 7 Hex bolt
48 Front output driveshaft
flange yoke
49 Front output driveshaft
yoke nut
50 Front output driveshaft
yoke (rubber)
51 Front output driveshaft
yoke deflector
52 Front output shaft seal
53 Front output shaft bearing
retainer ring
54 Front output shaft bearing
55 Shift sector spring screw
56 Screw
57 Shift sector and shaft oil seal
58 Shift sector and shaft retainer
59 Shifter shaft lever
1
60 Shift shaft lever nut
61 Shift sector assembly spring
62 Range fork bushing
63 Fork end pad
64 Range shift fork pin
65 Range shift fork center
66 Range shift assembly fork
67 Mode shift fork bracket pin
68 Mode shift fork center pad
69 Mode shift assembly fork
70 Mode shift fork spring cup
71 Mode shift fork spring
72 Mode shift fork
assembly bracket
73 Shift fork shaft
74 Shift sector
75 Shift selector shaft spacer
76 Drive chain
The Motor Manual Guy
7C-3
19
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4.4b Typical Command-Trac transfer case
(New Process 231 - exploded view
2
3
4
5
6
7
8
9
10
I
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Front yoke nut, seal washer,
yoke and oil seal
Shift detent plug, spring
and pin
Front retainer and seal
Front case
Vacuum switch and seal
Vent assembly
lnput gear bearing and
snap-ring
Low range gear snap-ring
lnput gear retainer
Low range gear
thrust washers
lnput gear
lnput gear pilot bearing
Low range gear
Range fork shift hub
Synchronizer hub snap-ring
Synchronizer hub springs
Synchronizer hub and inserts
Synchronizer sleeve
Synchronizer stop ring
Sap-ring
Output shaft front bearing
Output shaft (front)
Drive sprocket
Drive chain
Drive sprocket bearings
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
Output shaft rear bearing
Mainshaft
Oil seal
Oil pump assembly
Rear bearing
Snap-ring
Rear case
Fill plug and gasket
Drain plug and gasket
Rear retainer
Extension housing
Bushing
Oil seal
Oil pickup screen
Tube connector
Oil pickup tube
Pickup tube O-ring
Magnet
Range lever nut and washer
Range lever
O-ring and seal
Sector
Mode spring
Mode fork
Mode fork inserts
Range fork inserts
Range fork bushings
Range fork
7C
The Motor Manual Guy
7C-4~-----------
4.4c
Typical Selec-Trac transfer case (New Process 228) - exploded view
Spacer
Side gear
Differential
Pilot bearing rollers
O-ring seal
Rear output shaft
Oil pump
Speedometer drive gear
Shim kit
Mainshaft
Mainshaft thrust washer
Spline gear
Retaining ring
Sprocket
Spacer
Sprocket thrust washer
Side gear roller
Spacer (short)
Spacer (long)
Rear yoke
Nut and seal washer
Seal
Rear retainer
Plug assembly
Bolt
Identification tag
Plug assembly
Do we/ bolt
Dowel bolt washer
Case half dowel
Rear case half
Magnet
Front output shaft bearing
assembly race (thick)
3 4 Front output shaft bearing
assembly thrust
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
35 Front output shaft bearing
assembly race (thin)
36 Retaining ring
37 Chain
38 Driven sprocket
39 Front output shaft
4 0 Front output shaft
front bearing
41 Nut
42 Washer
43 Mode lever
4 4 Snap-ring
45 Range lever
46 O-ring retainer
4 7 O-ring seal
4 8 Front case half
49 Front output yoke
5 0 Low range plate bolt
5 1 lnput shaft oil seal
52 lnput shaft bearing
5 3 Stud
5 4 Ball
55 Plunger half dowel
56 Plunger spring
57 Screw
58 lnput race
59 lnput thrust bearing
6 0 lnput race (thick)
6 1 lnput shaft
62 lnput bearing
63 Planetary gear assembly
6 4 lnput gear thrust washer
65 Annulus gear assembly
66 Annulus bushing
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
9
92
93
94
95
96
Thrust washer
Retaining ring
Thrust bearing
High range sliding
clutch sleeve
Mode sliding clutch sleeve
Carrier
Carrier rollers
Rear retainer bolt
Vent
Vent seal
Output bearing
Bolt
Seal
Front output shaft
rear bearing
Output shaft inner bearing
Range sector
Range bracket (outer)
and spring
Range bracket (inner)
Mode selector
O-ring seal
Range rail
Low range lockout plate
Mode fork, rail and pin
Mode fork pad
Range fork
Range fork pads
Range bracket spring (inner}
Locking fork bushing
Locking fork pads
Locking fork
The Motor Manual Guy
4
4.4d
1
2
3
4
5
6
7
8
9
10
I1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
3
32
33
34
Typical Selec-Trac transfer case (New Process 229)
Spacer
Side gear
Viscous coupling
Pilot bearing rollers 15)
O-ring
Rear output shaft
Oil pump
Speedometer drive gear
Shims
Mainshaft
Mainshaft thrust washer
Spline gear
Retaining ring
Sprocket
Spacer
Sprocket thrust washer
Clutch gear
Mainshaft bearings
Bearing spacers (two short)
Bearing spacer (one long)
Rear yoke
Nut and seal washer
Seal
Rear retainer
Plug assembly
Bolt
Identification tag
Plug
Dowel bolt
Dowel bolt washer
Case half do we/
Rear case half
Magnet
Bearing race (thick)
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
Bearing
Bearing race (thin/
Retaining ring
Drive chain
Driven sprocket
Front output shaft
Front output shaft
front bearing
Nut
Washer
Mode lever
Snap-ring
Range lever
O-ring retainer
O-ring
Front case half
Front yoke
Bolt
lnput gear oil seal
lnput gear bearing
Stud
Detent ball
Pin
Spring
Screw
Bearing race (thin/
Thrust bearing
Bearing race (thick)
lnput gear
Pilot bearing
Planetary gear
lnput gear thrust washer
Annulus gear
exploded view
67 Annulus bushing
68 Thrust washer
69 Retaining ring
70 Thrust bearing
71 Range sleeve
72 Mode sleeve
73 Carrier
74 Carrier bearings
75 Rear retainer bolt
76 Vent
77 Vent seal
78 Output bearing
79 Bolt
80 Seal
81 Front output shaft
rear bearing
82 Output shaft bearing
83 Range sector
84 Range bracket (outer/
and spring
85 Range bracket (inner/
86 Mode sector
87 O-ring
88 Range rail
89 Low range lockout plate
90 Mode fork, rail and pin
91 Mode fork pad
92 Range fork
93 Range fork pads
94 Range bracket spring (inner/
95 Locking fork bushing
96 Locking fork pads
97 Locking fork
7C . .
The Motor Manual Guy
4.4e
Typical Selec-Trac transfer case (New Process 242) - exploded view
1 Front bearing retainer
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
and seal
Front case
Shift sector
Low range fork and inserts
Shift rail
Shift bracket
Slider bracket
Bushing and spring
Mode fork and inserts
Bushing
Fork spring
Bushing
Vent tube assembly
lnpur gear bearing and
snap-ring
Low range gear snap-ring
Retainer, low range gear
Thrust washer, low
range gear
Input gear
Rear case
;~ Drain/fill plugs
Rear bearing retainer
22 Extension housing
23 Bushing and oil seal
24 Vacuum switch
25 Magnet
26 Thrust ring
27 Snap-ring
28 Shift sleeve
29 Low range gear
30 Pilot bushing (input
31 gearlmainshaft)
Front output shaft front
bearing and snap-ring
32 Intermediate clutch shaft
33
Shift sleeve
34 Snap-ring
35 Mainshaft
36 Differential assembly
37 Oil pump tube O-ring
38 Oil pump pickup tube
and screen
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
Mainshaft bearing rollers
Drive sprocket
Drive chain
Snap-ring
Oil pump seal
Oil pump
Rear bearing and snap-ring
Front output shaft
rear bearing
Snap-ring
Driven sprocket
Front output shaft
Mainshaft bearing spacers
Shift lever washer and nut
Shift lever
Sector O-ring and seal
Detent pin, spring and plug
Seal plug
Front yoke nut, seal washer,
yoke, slinger and oil seal
The Motor Manual Guy
Chapter 7 Part C
parts department and auto parts stores. At any rate, the time and money
involved in an overhaul is almost sure to exceed the cost of a rebuilt
unit.
Nevertheless, it's not impossible for an inexperienced mechanic to
rebuild a transfer case if the special tools are available and the job is
done in a deliberate step-by-step manner so nothing is overlooked.
The tools necessary for an overhaul include internal and external
snap-ring pliers, a bearing puller, a slide hammer, a set of pin punches,
a dial indicator and possibly a hydraulic press. In addition, a large, sturdy
workbench and a vise or transmission stand will be required.
During disassembly of the transfer case, make careful notes of how
Transfer case
7C-7
each piece comes off, where it fits in relation to other pieces and what
holds it in place. Exploded views are included (see illustrations) to show
where the parts go
but actually noting how they are installed when
you remove the parts will make it much easier to get the transfer case
back together.
Before taking the transfer case apart for repair, it will help if you have
some idea what area of the transfer case is malfunctioning. Certain
problems can be closely tied to specific areas in the transfer case, which
can make component examination and replacement easier. Refer to
the Troubleshooting section at the front of this manual for information
regarding possible sources of trouble.
7C
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
Contents
Clutch components
removal. inspection and installation . . .
3
description and check
2
Clutch
Clutch fluid level check
See Chapter 1
Clutch hydraulic system
bleeding
8
Clutch master cylinder
removal,
6
overhaul and installation
Clutch pedal
removal and installation
9
Clutch release bearing
removal,
4
inspection and installation . . . . . . . . . . . . . . . . . . . . . . . . .
Clutch release cylinder
removal,
overhaul and installation
7
Differential lubricant level check
See Chapter 1
Driveline inspection
11
general information . . . 1 0
Driveshafts, differentials and axles
Driveshaft(s) - removal and installation
12
Flywheel removal and installation
See Chapter 2
Front axle assembly
removal and installation
18
removal,
Front axle hub and bearings
service and installation
15
Front axleshafts
removal, overhaul and installation
16
Front axle shift motor
check, removal and installation
17
General information
1
Pilot bearing
inspection and replacement
5
14
Pinion oil seal
replacement
Rear axle assembly
removal and installation
20
Rear axleshaft and bearing assembly
removal
and installation
19
Universal joints
replacement
13
Specifications
Clutch
Fluid type
See Chapter 1
Torque specifications
Ft-lbs
Pressure plate-to-flywheel bolts
Four-cylinder and V6 engines
lnline six-cylinder engine
Clutch/brake pedal pivot pin nut
23
40
20
Drivetrain
Torque specifications
Driveshaft U-joint strap bolts
Driveshaft-to-transfer case flange bolts
Front axle shift motor housing bolts
Front axleshaft hub nut
Front hub assembly-to-steering knuckle bolts
Front differential pinion shaft nut
Brake backing plate nuts
Rear axle U-bolt nuts
Ft-lbs (unless otherwise indicated)
14
22
1 0 8 in-lbs
175
75
2 10
32
4 4 to 59
The Motor Manual Guy
Chapter 8
1
Clutch and drivetrain
2
General information
The information in this Chapter deals w i t h the components from the
rear of the engine t o the drive wheels, except for the transmission and
transfer case, which are dealt with in the previous Chapter. For the
purposes of this Chapter, these components are grouped into three
categories; clutch, driveshaft and axles. Separate Sections within this
Chapter offer general descriptions and checking procedures for components in each o f the three groups.
Since nearly all the procedures covered in this Chapter involve working under the vehicle, make sure it's securely supported on sturdy jackstands or on a hoist where the vehicle can be easily raised and lowered.
8- 1
Clutch - description and check
Refer to illustrations 2. l a and 2.1b
1 All vehicles with a manual transmission use a single dry plate, diaphragm spring type clutch (see illustrations). The clutch disc has a
splined hub which allows it t o slide along the splines of the transmission
input shaft. The clutch and pressure plate are held in contact by spring
pressure exerted by the diaphragm in the pressure plate.
2 The clutch release system is operated by hydraulic pressure. The
hydraulic release system consists of the clutch pedal, a master cylinder
and fluid reservoir, the hydraulic line, a release (or slave) cylinder which
actuates the clutch release lever (models w i t h externally mounted
4
3
2.1a
Clutch components - early models
1 Pressure plate assembly
2 Clutch disc
3 Release bearing
4 Release lever
5 Clutch housing
CLUTCH
HOUSING
CLUTCH
COVER
CLUTCH
DISC
HYDRAULIC
THROWOUT
BEARING
8
RETAINING
NUT
,2. b
Clutch components - later models
The Motor Manual Guy
8-2
Chapter 8
Clutch and drivetrain
release cylinder) and the clutch release (or throwout) bearing. Later
models use a hydraulic release bearing, which is a combination release
bearinglslave cylinder assembly mounted inside the clutch housing.
3 When pressure is applied to the clutch pedal to release the clutch,
hydraulic pressure is exerted against the release bearing, either through
the release lever or the hydraulic release bearing. The bearing pushes
against the fingers of the diaphragm spring of the pressure plate
assembly, which in turn releases the clutch plate.
4 Terminology can be a problem when discussing the clutch components because common names are in some cases different from
those used by the manufacturer. For example, the driven plate is also
called the clutch plate or disc, the clutch release bearing is sometimes
called a throwout bearing, the release cylinder is sometimes called the
operating or slave cylinder.
5 Other than to replace components with obvious damage, some
preliminary checks should be performed to diagnose clutch problems.
a) The first check should be of the fluid level in the clutch master
cylinder. If the fluid level is low, add fluid as necessary and inspect
the hydraulic system for leaks. If the master cylinder reservoir
has run dry, bleed the system as described in Section 8 and retest
the clutch operation.
b) To check "clutch spin down time," run the engine at normal idle
speed with the transmission in Neutral (clutch pedal up engaged). Disengage the clutch (pedal down), wait several
seconds and shift the transmission into Reverse. No grinding
noise should be heard. A grinding noise would most likely indicate
a problem in the pressure plate or the clutch disc (assuming the
transmission is in good condition).
c) To check for complete clutch release, run the engine (with the
parking brake applied to prevent movement) and hold the clutch
pedal approximately 112-inch from the floor. Shift the transmission between 1st gear and Reverse several times. If the shift is
rough, component failure is indicated. Check the release cylinder
pushrod travel (externally mounted release cylinder models only).
With the clutch pedal depressed completely, the release cylinder
pushrod should extend substantially. If it doesn't, check the fluid
level in the clutch master cylinder.
d) Visually inspect the pivot bushing at the top of the clutch pedal
to make sure there is no binding or excessive play.
3
marks. The marks are usually an X, an 0 or a white letter. If they cannot
be found, scribe marks yourself so the pressure plate and the flywheel
will be in the same alignment during installation (see illustration).
6 Turning each bolt a little at a time, loosen the pressure plate-to..
flywheel bolts. Work in a criss-cross pattern until all spring pressure
is relieved. Then hold the pressure plate securely and completely
remove the bolts, followed by the pressure plate and clutch disc.
Inspection
Refer to illustrations 3.8, 3. 10 and 3. 12
7 Ordinarily, when a problem occurs in the clutch, it can be attributed
to wear of the clutch driven plate assembly (clutch disc). However,
all components should be inspected at this time.
8 Inspect the flywheel for cracks, heat checking, grooves and other
obvious defects (see illustration). If the imperfections are slight, a
machine shop can machine the surface flat and smooth, which is highly
recommended regardless of the surface appearance. Refer t o Chapter
2 for the flywheel removal and installation procedure.
Clutch components - removal. inspection and installation
Warning: Dust produced b y clutch wear and deposited on clutch components may contain asbestos, which is hazardous to your health. DO
NOT blow it out with compressed air and DO NOT inhale it. DO NOT
use gasoline or petroleum-based solvents to remove the dust. Brake
system cleaner should be used to flush the dust into a drain pan. After
the clutch components are wiped clean with a rag, dispose of the contaminated rags and cleaner in a covered, marked container.
3.5 Mark the relationship of the pressure plate to the flywheel
(arrow) (in case you are going to reuse the same pressure plate)
Removal
Refer to illustration 3.5
1 Access to the clutch components is normally accomplished by
removing the transmission, leaving the engine in the vehicle. If, of
course, the engine is being removed for major overhaul, then check
the clutch for wear and replace worn components as necessary.
However, the relatively low cost of the clutch components compared
to the time and trouble spent gaining access to them warrants their
replacement anytime the engine or transmission is removed, unless
they are new or in near perfect condition. The following procedures
are based on the assumption the engine will stay in place.
2 Referring t o Chapter 7 Part A, remove the transmission from the
vehicle. Support the engine while the transmission is out. Preferably,
an engine hoist should be used to support it from above. However,
if a jack is used underneath the engine, make sure a piece of wood
is positioned between the jack and oil pan to spread the load. Caution:
The pickup for the oil pump is very close to the bottom of the oil pan.
If the pan is bent or distorted in any way, engine oil starvation could
occur.
3 Remove the release cylinder (models with externally mounted
cylinders) (see Section 7). On models with a hydraulic release bearing
assembly, disconnect the hydraulic line at the clutch housing.
4 To support the clutch disc during removal, install a clutch alignment
tool through the clutch disc hub.
5 Carefully inspect the flywheel and pressure plate for indexing
3.8 Check the surface of the flywheel for cracks, hot spots
(dark colored areas) and other obvious defects; resurfacing by
a machine shop will correct minor defects - the surface on
this flywheel is in fairly good condition; however, resurfacing
is always a good idea
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
9 lnspect the pilot bearing (see Section 5).
1 0 lnspect the lining on the clutch disc. There should be at least 1 /16inch of lining above the rivet heads. Check for loose rivets, distortion,
cracks, broken springs and other obvious damage (see illustration).
As mentioned above, ordinarily the clutch disc is routinely replaced,
so if in doubt about the condition, replace it with a new one.
1 1 Check the condition of the release bearing following the procedure
in Section 4.
12 Check the machined surfaces and the diaphragm spring fingers
of the pressure plate (see illustration). If the surface is grooved or otherwise damaged, replace the pressure plate. Also check for obvious
damage, distortion, cracking, etc. Light glazing can be removed with
medium grit emery cloth. If a new pressure plate is required, new and
factory-rebuilt units are available.
Installation
8-3
18 Install the clutch release bearing as described in Section 4.
19 Install the transmission, release cylinder (externa·11y mounted type
only) and all components removed previously. Tighten all fasteners t o
the proper torque specifications.
4
Clutch release bearing - removal, inspection and installation
Warning: Dust produced b y clutch wear and deposited on clutch components may contain asbestos, which is hazardous to your health. DO
NOT blow i t out with compressed air and DO NOT inhale it. DO NOT
use gasoline or petroleum-based solvents to remove the dust. Brake
system cleaner should be used to flush the dust into a drain pan. After
the clutch components are wiped clean with a rag, dispose of the contaminated rags and cleaner in a covered, marked container.
Refer to illustration 3. 14
13 Before installation, clean the flywheel and pressure plate machined
surfaces with lacquer thinner or acetone. It's important that no oil or
grease is on these surfaces or the lining of the clutch disc. Handle the
parts only with clean hands.
1 4 Position the clutch disc and pressure plate against the flywheel
with the clutch held in place with an alignment tool (see illustration).
Make sure it's installed properly (most replacement clutch plates will
be marked "flywheel side" or something similar - if not marked, install
the clutch disc with the damper springs toward the transmission).
15 Tighten the pressure plate-to-flywheel bolts only finger tight, working around the pressure plate.
1 6 Center the clutch disc by ensuring the alignment tool extends
through the splined hub and into the pilot bearing in the crankshaft.
Wiggle the tool up, down or side-to-side as needed to bottom the tool
in the pilot bearing. Tighten the pressure plate-to-flywheel bolts a little
at a time, working in a criss-cross pattern to prevent distorting the
cover. After all of the bolts are snug, tighten them to the specified
torque. Remove the alignment tool.
17 Using high-temperature grease, lubricate the inner groove of the
release bearing (see Section 4). Also place grease on the release lever
contact areas (on models with release levers) and the transmission input
shaft bearing retainer.
3.10 The clutch disc
I Lining
will wear down
in use
2 Rivets - secure the lining
and will damage the pressure
plate or flywheel surface if
allowed to contact i t
3 Marks - "Flywheel side" or
something similar
EXCESS
NORMAL FINGER WEAR
EXCESSIVE FINGER WEAR
8
EXCESSIVE FINGER WEAR
EXCESSIVE SCOfllNG
3.1 2
BROKEN OR BENT FINGERS
CLUTCH CHATTER
Replace the pressure plate if excessive wear or
damage is noted
3.14 Center the clutch disc in the pressure plate with an
alignment tool before the bolts are tightened
The Motor Manual Guy
8-4
Chapter 8 Clutch and drivetrain
Removal
1 Following the appropriate procedure outlined in Chapter 7, remove
the transmission.
Externally m o u n t e d release cylinder
2 Unbolt the release cylinder from the clutch housing and pull it out
of its recess. Hang it out of the way with a piece of wire (it's not
necessary to disconnect the hose).
3 Remove the release lever from the ball stud, slide the bearing off
the transmission input shaft bearing retainer and separate the bearing
from the lever.
Release bearing assembly
Refer to illustrations 4.4 and 4.5
4 Unbolt the insulator plate from the clutch housing and slide the
plate and rubber insulator off the lines (see illustration).
5 Remove the pressed metal retaining nut from the base of the
hydraulic release bearing (see illustration) and slide the release bearing assembly off the transmission input shaft bearing retainer.
Inspection
6 Hold the center portion of the bearing stationary and rotate the
outer portion while applying pressure. If the bearing doesn't turn
smoothly or if it's noisy, replace it with a new one. Wipe the bearing
with a clean rag and inspect it for damage and wear. Don't immerse
the bearing in solvent - it is sealed for life and immersion would ruin it.
7 Hydraulic release bearings must also be checked for fluid leakage
where the rubber seal meets the cylinder housing. If any leakage is
evident, replace the entire assembly.
4.4 Remove the bolts (arrows), then slide the
plate and rubber insulator back on the lines
lnstallation
8 Installation for either style bearing is the reverse of the removal
procedure, with a couple of points which must be noted.
9 Lightly lubricate the transmission input shaft bearing retainer with
high-temperature grease. On hydraulic release bearing models, install
a new pressed metal retaining nut. Note: When new, the hydraulic
release bearing is retained in the compressed position by nylon straps they are designed to break the first time the clutch pedal is depressed,
so there is no need to remove them.
10 With the non-hydraulic release bearing (externally mounted release
cylinder), lubricate the ends of the release lever and the ball socket
with high-temperature grease. Also pack the inner groove of the bearing
with the same grease. When installing the bearing and lever, make sure
the bearing retaining spring clips are engaged with the lever ends.
1 1 Install the transmission (see Chapter 7). On hydraulic release bearing models, connect the hydraulic line and bleed the system as described in Section 8.
5
4.5 Remove the hydraulic release bearing retaining
nut - be sure t o use a new nut upon installation
Pilot bearing - inspection and replacement
Refer to illustrations 5.9, 5. 1Oa and 5. Ob
1 The clutch pilot bearing is a needle roller type bearing which is
pressed into the rear of the crankshaft. Its primary purpose is to support
the front of the transmission input shaft. The pilot bearing should be
inspected whenever the clutch components are removed from the
engine. Due to its inaccessibility, if you are in doubt as to its condition,
replace it with a new one. Note: If the engine has been removed from
the vehicle, disregard the following steps which do not apply.
2 Remove the transmission (refer t o Chapter 7 Part A).
3 Remove the clutch components (Section 3).
4 Inspect for any excessive wear, scoring, lack of grease, dryness
or obvious damage. If any of these conditions are noted, the Gearing
should be replaced. A flashlight will be helpful to direct light into the
recess.
5 Removal can be accomplished with a special puller and slide hammer, but an alternative method also works very well.
6 Find a solid steel bar which is slightly smaller in diameter than the
bearing. Alternatives to a solid bar would be a wood dowel or a socket
with a bolt fixed in place to make it solid.
7 Check the bar for fit it should just slip into the bearing with very
little clearance.
8 Pack the bearing and the area behind it (in the crankshaft recess)
with heavy grease. Pack it tightly to eliminate as much air as possible.
5.9 Pack the recess behind the bearing with heavy grease
and force it out hydraulically with a steel rod slightly
smaller than the bore i n the bearing - when the hammer
strikes the rod, the bearing will pop out of the crankshaft
9 Insert the bar into the bearing bore and strike the bar sharply with
a hammer which will force the grease to the back side of the bearing
and push it out (see illustration). Remove the bearing and clean all
grease from the crankshaft recess.
1 0 To install the new bearing, pack the inside of the bearing and lightly
lubricate the outside surface with wheel bearing grease. Drive the bear-
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
8-5
BEARING SEAL
MUST FACE
TRANSMISSION
5.10a The pilot bearing incorporates an O-ring seal which
cannot be replaced separately. If there is any indication that the
seal is leaking, or if the bearing is dry, replace it. The bearing
must be installed with the seal towards the transmission.
ing into the recess with an alignment tool or bushing driver. The seal
must face out and the bearing must go in perfectly straight (see illustrations).
11 Install the clutch components, transmission and all other components removed previously, tightening all fasteners properly.
5.10b
6
Tap the bearing in using a bushing driver or a socket
Clutch master cylinder - removal, overhaul and installation
Note: Before beginning this procedure, contact localparts stores and
dealer service departments concerning the purchase of a rebuild kit
or a new master cylinder. Availability and cost of the necessary parts
may dictate whether the cylinder is rebuilt or replaced with a new one.
If it's decided t o rebuild the cylinder, inspect the bore as described
in Step 12 before purchasing parts.
Removal
Refer to illustrations 6 . 3 and 6.5
1 Disconnect the cable from the negative battery terminal.
2 Remove the clutch master cylinder reservoir cap, and, using a suction gun or large syringe, suck out as much fluid as possible.
3 Disconnect the hydraulic line from the cylinder, using a flare nut
wrench, if available. Some models have a separable reservoir, which,
when removed, makes access to the fitting much easier (see illustration).
4 Remove the lower master cylinder mounting nut.
5 Working under the dash, disconnect the pushrod from the clutch
pedal. It is retained by a cotter pin, plastic washer and spring washer
(see illustration).
6 Also from under the dash, remove the cylinder upper mounting
nut (see illustration 6.5). Rather than attempt to loosen the nut from
this position, it is much easier to simply hold the nut while an assistant unscrews the bolt from the engine side of the firewall.
7 Pull the cylinder out of the hole in the firewall. Be careful not t o
let any of the fluid drip onto the vehicle's paint, as it will damage it.
Overhaul
Refer to illustrations 6.10, 6.1 1, 6.14a and 6.14b
8 On models with a removable reservoir, detach the reservoir from
the cylinder body by loosening the clamp.
9 Mount the cylinder in a vise, with the vise jaws clamping on the
mounting flange. It's a good idea to line the jaws of the vise with wood
or rags to prevent damage t o the flange surface.
10 Pry the dust boot from the cylinder. Push in on the pushrod to
depress the plunger, then remove the snap-ring with a pair of snapring pliers (see illustration). Remove the pushrod and boot. Discard
the snap-ring.
8
6.3 To avoid rounding off the corners
of the fitting nut (arrow), use a flare nut
wrench when loosening it
6.5 Remove the cotter pin (1) (barely
visible i n this photo), plastic washer and
spring washer, then disconnect the pushrod
from the clutch pedal pin; next, hold the upper
mounting nut (2) with a wrench while an
assistant unscrews the mounting bolt from the
engine side of the firewall
6.10 Push in on the pushrod and
remove the snap-ring with a pair of
snap-ring pliers
The Motor Manual Guy
Chapter 8
8-6
Clutch and drivetrain
VALVE
STEM
6.11
Pull the plunger assembly from the bore
11 Pull the plunger assembly from the bore (see illustration). If it's
hard to pull out, remove the cylinder from the vise, turn it so the flanged
end is down and tap it sharply against a block of wood.
12 Inspect the bore of the cylinder for scratches, score marks, pitting
and ridges. The surface must be smooth to the touch. If the bore isn't
perfectly smooth, the master cylinder must be replaced with a new
or factory rebuilt unit.
13 If the cylinder will be rebuilt, use the parts contained in the rebuild
kit and follow any specific instructions which accompany the kit. Wash
all parts to be re-used with brake cleaner or clean brake fluid. DO NOT
use petroleum-based solvents.
1 4 Compress the spring and, using a small screwdriver, pry up on the
valve stem retainer tab to release the retainer, spring and valve stem
assembly (see illustrations).
15 Remove the plunger, then remove and discard the seals from the
plunger.
16 Separate the spring retainer and the valve stem assembly from the
plunger spring.
17 Remove the valve stem from the spring retainer. Remove the stem
tip seal and spring washer from the stem. Discard the seal.
18 Install the new plunger seals on the plunger, making sure the lips
of the seals face the small end of the plunger.
6.14a
Pry the retainer tab out with a small screwdriver t o
release the valve stem
19 lnstall the new valve stem tip seal and spring washer onto the valve
stem. The shoulder of the stem tip seal must fit into the undercut at
the end of the stem.
2 0 Place the spring retainer on the valve stem and over the spring
washer, making sure the large end of the retainer is facing the seal
end of the valve stem.
21 Slide the stem and spring retainer assembly into place on the
plunger spring.
22 Holding the plunger in one hand, compress the spring against the
plunger and guide the valve stem into the hole in the retainer. When
the end of the stem passes through the hole, bend the tab on the retainer in to lock the stem and retainer to the plunger.
23 Lubricate the cylinder bore and plunger assembly with clean brake
fluid. lnstall the assembly in the cylinder bore.
2 4 Place a new seal, snap-ring and dust boot on the pushrod. Lubricate
the end of the pushrod, the seal and the lips of the dust boot with the
grease provided in the rebuild kit, lnstall the pushrod, depress the
plunger and seat the snap-ring in its groove.
25 Slide the pushrod seal (not shown in illustration 6.14b) and dust
boot up against the end of the cvlinder and stretch the boot over the
cylinder body.
6.14b Exploded view of the clutch
master cylinder components
I Pushrod
2 Dust boot
3 Snap-ring
4 Washer
A
5 Master cylinder body
6 Reservoir cap
7 Reservoir
8 Retaining clamp
9 Stem tip seal
10 Valve stem
I I Retainer spring
12 Spring retainer
13 Plunger spring
14 Valve stem retainer
15 Plunger rear seal
16 Plunger front seal
17 Plunger
18 Valve stem assembly
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
8-7
Installation
26 Position the cylinder against the firewall and install the lower
mounting nut, but don't tighten it fully yet.
27 Connect the hydraulic line t o the cylinder, tightening the fitting
by hand only. Since the cylinder is still loose, it can be wiggled around
slightly to make it easier to align the fitting threads.
28 lnstall the upper mounting bolt, again using an assistant to tighten
the bolt while the nut is held stationary.
29 Connect the pushrod to the clutch pedal, install the washers and
a new cotter pin.
3 0 Tighten the lower mounting nut.
31 Tighten the hydraulic line fitting securely.
3 2 lnstall the fluid reservoir if it was previously removed.
3 3 Fill the reservoir with brake fluid conforming t o DOT 3 specifications and bleed the system as described in Section 8.
7
Clutch release cylinder - removal, overhaul and installation
Note: This procedure applies to externally mounted release cylinders
only (the hydraulic release bearing mounted inside the clutch housing
is not serviceable). Before beginning this procedure, contact local parts
stores and dealer service departments concerning the purchase of a
rebuild kit or a new release cylinder. Availability and cost of the
necessary parts may dictate whether the cylinder is rebuilt or replaced
with a new one. If it's decided to rebuild the cylinder, inspect the bore
as described in Step 8 before purchasing parts.
Removal
1 Disconnect the negative cable from the battery.
2 Raise the vehicle and support it securely on jackstands.
3 Disconnect the hydraulic line at the release cylinder. If available,
use a flare nut wrench on the fitting, which will prevent the fitting from
being rounded off. Have a small can and rags handy, as some fluid
will be spilled as the line is removed.
4 Remove the t w o release cylinder mounting bolts.
5 Remove the release cylinder.
Location of the bleeder screw (arrow) on models with
a hydraulic clutch release bearing
lnstallation
1 0 Install the release cylinder on the clutch housing. Make sure the
pushrod is seated in the release fork pocket.
1 1 Connect the hydraulic line to the release cylinder. Tighten the fitting
1 2 Fill the clutch master cylinder with brake fluid conforming to DOT 3
specifications.
1 3 Bleed the system as described in Section 8.
1 4 Lower the vehicle and connect the negative battery cable.
8 Clutch hydraulic system - bleeding
Overhaul
Refer to illustration 7.7
6 Separate the rubber boot from the cylinder.
7 Pull the pushrod, boot, plunger and spring from the cylinder (see
illustration).
8 Carefully inspect the bore of the cylinder. Check for deep scratches,
score marks and ridges. The bore must be smooth to the touch. If any
imperfections are found, the release cylinder must be replaced with
a new one.
9 Using the new parts in the rebuild kit, assemble the components
using plenty of fresh brake fluid for lubrication. Note the installed direction of the spring and the seal (the seal lips must point toward the
spring).
3
4
I
7.7
8.5
2
Clutch release cylinder internal components
1 Boot
2 Pushrod
3 Plunger
4 Spring
5 Seal
Refer to illustration 8.5
1 The hydraulic system should be bled to remove all air whenever
any part of the system has been removed or if the fluid level has fallen
so low that air has been drawn into the master cylinder. The procedure
is very similar to bleeding a brake system.
2 Fill the master cylinder with new brake fluid conforming to DOT 3
specifications. Caution: Don't re-use any of the fluid coming from the
system during the bleeding operation. Also, don't use fluid which has
been inside an open container for an extended period of time.
3 Raise the vehicle and place it securely on jackstands to gain access
to the release cylinder (or bleeder screw), which is located on the left
side of the clutch housing.
4 On models with an externally mounted release cylinder, remove
the t w o release cylinder mounting bolts and pull the cylinder from the
clutch housing. Remove the pushrod from the cylinder, then compress
the plunger into the cylinder with a universal gear puller or a C-clamp
and socket.
5 Remove the dust cap which fits over the bleeder screw (see illustration) and push a length of plastic hose over the screw. Place the other
end of the hose in a clear container with about t w o inches of brake
fluid. The hose end must be in the fluid at the bottom of the container.
6 Have an assistant depress the clutch pedal and hold it. Open the
bleeder screw on the release cylinder, allowing fluid to flow through
the hose. Close the bleeder screw when the flow of bubbles or old
fluid ceases. Once closed, have your assistant release the pedal.
7 Continue this process until all air is evacuated from the system,
indicated by a solid stream of fluid being ejected from the bleeder screw
each time with no air bubbles in the hose or container. Keep a close
watch on the fluid level inside the master cylinder - if the level drops
too low, air will be sucked back into the system and the process will
have to be started all over again.
8 lnstall the pushrod, mount the release cylinder (externally mounted
cylinder only) and lower the vehicle. Top off the fluid level and check
carefully for proper operation before placing the vehicle in normal
service.
8
The Motor Manual Guy
Chapter 8
8-8
Clutch and drivetrain
9 Clutch pedal - removal and installation
Removal
1 Disconnect the cable from the negative battery terminal.
2 Remove the cotter pin and washer and detach the clutch master
cylinder pushrod from the clutch pedal (see illustration 6.5). Remove
the pedal return spring.
3 Remove the pivot bolt nut from the right end of the pivot bolt, then
slide the bolt out. Note: While doing this, slide another bolt in from
the opposite side to support the brake pedal.
4 Remove the clutch pedal and inspect it for wear and distortion.
Check the bushings for excessive wear, replacing parts as necessary.
Installation
5 Lubricate the pedal bushings with multi-purpose grease and position the pedal in its bracket. Install the bolt from the left side, forcing
out the bolt that was installed to support the brake pedal. Install the
nut and tighten it securely.
6 Connect the clutch master cylinder pushrod to the pedal and install
the washer and a new cotter pin. lnstall the pedal return spring.
10 Driveshafts, differentials and axles
-
general information
Refer to illustrations 10.2 and 10.3
There are t w o types of front (4WD only) and rear driveshafts available
in the vehicles covered in this manual. On 4WD models, their designated
application is determined by the model of transfer case installed.
Both style front driveshafts are equipped with a slip yoke and single
cardan universal joint at the lower (front axle) end. The type 1 front
driveshaft employs a double offset constant velocity joint at the upper
(transfer case) end, where the type 2 shaft uses a double cardan universal joint (see illustration). The slip yokes and universal joints are
10.2 The t w o types of front driveshafts
Constant velocity
(double offset) type joint
2 U-joint
3 Double cardan joint
4 U-joint
equipped with grease fittings and require periodic lubrication (see Chapter 1 ).
The rear driveshaft on Command-Trac vehicles is a one piece shaft
with welded yokes at each end. Vehicles with the Selec-Trac system
employ a shaft with a welded yoke at the rear and a slip yoke at the
front (see illustration).
The front and rear driveshafts are finely balanced during production
and whenever they are removed or disassembled, they must be
reassembled and installed in the exact manner and positions they were
originally in, t o avoid excessive vibration.
standard
Two types of differentials are used with these vehicles
differentials and as an option, Trac-Loc differentials. The latter style
has the ability to transfer torque from one wheel to the other if traction
is lost and the wheel begins to spin.
The front axle shafts (4WD models) are equipped with a universal
joint at the end of each axle, which allows the front wheels t o turn
right and left while transmitting torque. Vehicles equipped with Command-Trac four-wheel drive are fitted with single cardan U-joints. SelecTrac vehicles utilize a constant velocity style joint. Each system (except for later Selec-Trac equipped vehicles) has a front axle disconnect
feature which disengages the right front axle via a splined shift collar
which joins the right-side intermediate axle with the outer axle. The
system is controlled by a vacuum motor and shift fork, actuated when
the transfer case lever is shifted into one of the 4WD ranges. When
disengaged, the differential is allowed to free-wheel instead of turning
the ring gear, pinion and front driveshaft, thereby saving unnecessary
wear on these components during two-wheel drive operation.
The front axle housing on 4WD models is held in alignment with the
body by four control arms and a track rod.
The rear axles are the semi-floating type, supported on the outer ends
by the rear wheel bearings which are pressed onto the axleshafts. The
axle housing is held in alignment to the body by the suspension leaf
springs.
Because of the complexity and critical nature of the differential adjustments, as well as'the special equipment needed to perform the
operations, disassembly of the differential should be done by a dealer
service department or repair shop.
10.3 The t w o types of rear driveshafts - the type 1
shaft (top) has a welded yoke at each end, while the type
2 shaft (bottom) has a welded yoke at one end and a
splined slip yoke a t the other
I
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
8-9
same position to preserve the balance. On vehicles with Selec-Trac
11
4WD (welded yokes at both ends of the driveshaft), also mark the rela-
Driveline inspection
1
2
Raise the rear of the vehicle and support it securely on jackstands.
Crawl under the vehicle and visually inspect the driveshaft. Look
for any dents or cracks in the tubing. If any are found, the driveshaft
must be replaced.
3 Check for any oil leakage at the front and rear of the driveshaft.
Leakage where the driveshaft enters the transmission or transfer case
indicates a defective rear transmission or transfer case seal. Leakage
where the driveshaft enters the differential indicates a defective pinion
seal. For these repair operations refer to Chapter 7 and Section 1 4 ,
respectively.
4 While under the vehicle, have an assistant turn the rear wheel so
the driveshaft will rotate. As it does, make sure the universal joints
are operating properly without binding, noise or looseness.
5 The universal joint can also be checked with the driveshaft motionless, by gripping your hands on either side of the joint and attempting
to twist the joint. Any movement at all in the joint is a sign of considerable wear. Lifting up on the shaft will also indicate movement in
the universal joints.
6 Finally, check the driveshaft mounting bolts at the ends to make
sure they are tight.
7 On 4WD models, the above driveshaft checks should be repeated
on the front driveshaft. In addition, check for grease leakage around
the sleeve yoke, indicating failure of the yoke seal.
8 Check for leakage where the driveshafts connect t o the transfer
case and front differential. Leakage indicates worn oil seals.
9 Also check for leakage at the ends of the axle housings (at the
drum brake backing plates), which would indicate a defective axle seal.
12
tionship of the front driveshaft yoke to the transfer case yoke.
4 Remove the rear universal joint bolts and straps (see illustration
12.3). Turn the driveshaft (or tires) as necessary to bring the bolts into
the most accessible position. Remove the front U-joint bolts and straps
on Selec-Trac models.
5 Tape the bearing caps to the spider to prevent the caps from coming off during removal.
6 Lower the rear of 'the driveshaft and then slide the front out of
the transmission or transfer case.
7 To prevent loss of fluid and protect against contamination while
the driveshaft is out, wrap a plastic bag over the transmission or transfer
case housing and hold it in place with a rubber band (2WD and
Command-Trac 4WD vehicles only).
Installation
8 Remove the plastic bag from the transmission or transfer case and
wipe the area clean, Inspect the oil seal carefully. Procedures for replacement of this seal can be found in Chapter 7.
9 Slide the front of the driveshaft into the transmission (2WD) or
transfer case (Command-Trac models only). On Selec-Trac equipped
vehicles, connect the front of the driveshaft to the transfer case yoke
(making sure the match marks line up) and install the U-joint straps
and bolts. Tighten the bolts to the specified torque.
1 0 Raise the rear of the driveshaft into position, checking to be sure
the marks are in alignment. If not, turn the rear wheels to match the
pinion flange and the driveshaft.
1 1 Remove the tape securing the bearing caps and install new straps
and bolts. Tighten the bolts to the specified torque.
Driveshafts - removal and installation
--
Note: Whenever a driveshaft is removed, new U-joint straps must be
used during installation.
Rear driveshaft
Refer to illustration 12.3
Removal
Disconnect the negative cable from the battery.
Raise the vehicle and support it securely on jackstands. Place the
transmission in Neutral with the parking brake off.
3 Using a scribe, white paint or a hammer and punch, place marks
on the driveshaft and the differential yoke in line with each other (see
illustration). This is to make sure the driveshaft is reinstalled in the
2
Front drivesha f t (4WD)
Refer t o illustration 12.12
1 2 Using white paint, chalk or a scribe, mark the relationship of the
upper universal joint flange to the transfer case companion flange (see
illustration). Also mark the relationship of the lower U-joint to the front
differential pinion shaft yoke.
1 3 Remove the lower U-joint strap bolts. Unbolt the upper U-joint
flange from the transfer case companion flange (see illustration 12.1 2)
and remove the shaft from the vehicle. Tape the bearing caps t o the
spider t o prevent the caps fom falling off.
1 4 Installation is the reverse of the removal procdure. Be sure to
tighten the fasteners to the specified torque.
8
12.3 Before removing the bolts, mark the relationship of the
driveshaft yoke to the differential pinion shaft yoke - to
prevent the driveshaft from turning when loosening the flange
bolts, insert a screwdriver through the yoke
12.12 On the upper U-joint, mark the relationship of the
U-joint joint flange to the transfer case companion flange
- when removing the bolts, insert a screwdriver through
the U-joint to prevent the driveshaft from turning
The Motor Manual Guy
Chapter 8
8-10
13.2
Clutch and drivetrain
13.4 To press the universal joint out of the driveshaft
yoke, set it up in a vise with the small socket pushing the
joint and bearing cap into the large socket
A pair of needle-nose pliers can be used to remove
the universal joint snap-rings
1 3 Universal joints
replacement
STRIKE TUBE YOKE
EAR IN THIS AREA
Refer to illustrations 13.2, 13.4 and 13.9
Note: A press or large vise will be required for this procedure. It may
be a good idea to take the driveshaft to a repair or machine shop where
the universaljoints can be replaced for you, normally at a reasonable
charge.
1 Remove the driveshaft as outlined in the previous Section.
Single cardan U-joint (front or rear driveshaft)
2 Using a small pair of pliers, remove the snap-rings from the spider
(see illustration).
3 Supporting the driveshaft, place it in position on either an arbor
press or on a workbench equipped with a vise.
4 Place a piece of pipe or a large socket with the same inside diameter
over one of the bearing caps. Position a socket which is of slightly
smaller diameter than the cap on the opposite bearing cap (see illustration) and use the vise or press to force the cap out (inside the pipe
or large socket), stopping just before it comes completely out of the
yoke. Use the vise or large pliers to work the cap the rest of the way out.
5 Transfer the sockets to the other side and press the opposite bearing cap out in the same manner.
6 Pack the new universal joint bearings with grease. Ordinarily,
specific instructions for lubrication will be included with the universal
joint servicing kit and should be followed carefully.
7 Position the spider in the yoke and partially install one bearing cap
in the yoke. If the replacement spider is equipped with a grease fitting,
be sure it's offset in the proper direction (toward the driveshaft).
8 Start the spider into the bearing cap and then partially install the
other cap. Align the spider and press the bearing caps into position,
being careful not to damage the dust seals.
9 Install the snap-rings. If difficulty is encountered in seating the snaprings, strike the driveshaft yoke sharply with a hammer. This will spring
the yoke ears slightly and allow the snap-rings t o seat in the groove
(see illustration).
10 lnstall the grease fitting and fill the joint with grease. Be careful
not to overfill the joint, as this could blow out the grease seals.
11 Install the driveshaft. Tighten the flange bolts t o the specified
torque.
13.9 If the snap-ring will not seat in the groove, strike the
yoke with a hammer. This will relieve tension that has set
up in the yoke, and slightly spring the yoke ears. This
should also be done if the joint feels tight when assembled.
-
14
Pinion oil seal
replacement
Refer to illustrations 14.6a and 14.6b
1 A pinion shaft oil seal failure results in the leakage of differential
gear lubricant past the seal and onto the driveshaft yoke or flange. The
seal is replaceable without removing or disassembling the differential.
Double cardan U-joint (upper joint on
some front driveshafts)
12 Use the above procedure, but note that it will have to be repeated
because the double card an joint is made up of t w o single card an joints.
Note: The double cardan joint must be replaced as an assembly - don't
attempt to replace half of it, even if only one cross-and-roller assembly
is worn.
Double offset constant velocity joint (upper
joint on some front driveshafts)
13 As of the time of writing, no information was available on this type
of joint. Consult your local Jeep dealer service department.
14.6a
Mark the relationship of the pinion shaft to the
pinion shaft yoke
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
8-1 1
shaft spines and, using a soft-faced hammer, tap the pinion shaft yoke
onto the shaft, making sure the match-marks line up.
11 Coat the threads of a new pinion shaft nut with multi-purpose
grease and, using the holder to hold the flange, tighten the nut just
enough t o eliminate all end-play in the pinion shaft.
12 Turn the pinion shaft yoke several times to seat the bearing.
1 3 Using a torque wrench, see how much torque is required to turn
the pinion shaft. The desired preload is the previously recorded torque
value plus five inch-pounds. If the preload is less than desired, retighten
the nut in small increments until the desired preload is reached. If the
maximum torque (add five inch-pounds to the torque required to loosen
the nut on disassembly) is reached before the preload figure is obtained, the bearing spacer must be replaced by a repair shop. Note: Do
n o t back o f f the pinion n u t to reduce the preload. After the preload
is properly adjusted, proceed to Step 17.
Front differential
14.6b Hold the pinion shaft yoke i n place and loosen the
nut with a torque wrench, noting the torque necessary t o
loosen the n u t
2 Loosen the rear wheel lug nuts, raise the vehicle and place it on
jackstands.
3 Remove the rear wheels and brake drums.
4 Disconnect the driveshaft from the pinion shaft yoke (see Section 12).
1 4 Using the techniques described in Steps 6, 7 and 8, remove the
pinion shaft nut and washer, pull the yoke from the shaft and remove
the seal.
1 5 Following Steps 9 and 10, install the seal and pinion shaft yoke.
1 6 Lubricate the pinion shaft nut with multi-purpose grease. Install
the washer and nut, then tighten the nut to the specified torque.
Front and rear differentials
17 Connect the driveshaft to the pinion shaft yoke (see Section 12).
18 Install the brake drums and wheels, lower the vehicle to the ground
and tighten the lug nuts to the specifed torque (rear only).
19 Test drive the vehicle and check around the differential pinion shaft
yoke for evidence of leakage.
Rear differential
5 Using a torque wrench, slowly turn the pinion shaft nut and
measure the torque required t o turn the pinion.
6 Mark the relationship of the pinion shaft to the pinion shaft yoke
(see illustration). Hold the pinion shaft yoke with a large pair of adjustable pliers, then remove the nut with a torque wrench, noting the torque
necessary to remove the nut (see illustration).
7 Remove the pinion shaft yoke from the shaft, using a puller if necessary.
8 After noting what the visible side of the oil seal looks like, carefully
pry it out of the differential with a screwdriver or pry bar. Be careful
not to damage the splines on the pinion shaft.
9 Lubricate the new seal lip with moly-based grease or differential
lubricant and carefully install it in position in the differential. Using a
seal driver or a short section of pipe of the proper diameter and a hammer, carefully drive the seal into place.
1 0 Clean the sealing lip contact surface of the pinion shaft yoke. Apply
a thin coat of moly-based grease to the seal contact surface and the
15
Front axle hub and bearings
service and installation
removal,
Refer to 1'l/1.1strations 15.1, 15.4a and 15.4b
Note: This procedure applies to 4 WD vehicles only. For the 2 WD bearing servicing procedure, refer to Chapter 1.
Removal
1 Pry the hubcap from the wheel, remove the cotter pin and nut lock
then loosen the axle hub nut (see illustration).
2 Loosen the front wheel lug nuts, raise the front of the vehicle and
support it securely on jackstands. Remove the wheel.
3 Remove the disc brake caliper and disc (see Chapter 9).
4 Remove the axle hub nut. Unbolt the hub assembly from the steering knuckle and tap it out of the knuckle bore (see illustrations). If the
axle sticks in the hub splines, push it out of the hub with a puller.
8
15.1 Before raising the vehicle, remove
the cotter pin and nut lock, then loosen
the axle hub nut
15.4a Remove the three bolts (arrows)
(one is barely visible i n this photo) that
secure the hub assembly t o the steering
knuckle - a twelve-point socket will
be necessary
15.4b
Carefully tap the hub assembly
out of the steering knuckle
The Motor Manual Guy
Chapter 8
8-12
Clutch and drivetrain
Service
5 Due t o the special tools and expertise required to separate and
reassemble the hub and bearings, this job should be left t o a dealer
service department or repair shop.
lnstallation
6
Using sandpaper or emery cloth, clean the opening in the steering
knuckle to remove any rust or dirt that may be present. Lubricate the
axleshaft splines with wheel bearing grease. Smear the opening in the
steering knuckle with wheel bearing grease and install the hub assembly, tightening the bolts t o the specified torque.
7 Install the washer and hub nut, tightening the nut securely. Install
the brake disc and caliper (see Chapter 9), mount the wheel and lower
the vehicle. Tighten the lug nuts to the specified torque.
8 Tighten the axle hub nut to the specified torque and install the nut
lock and a new cotter pin. Install the hubcap.
1 6 Front axleshafts - removal, overhaul and installation
Note: This procedure applies to 4WD models only.
16.4 Once the hub and bearing assembly has been removed,
the axleshaft can be pulled straight out of the housing
Removal
Left or right outer axle
Refer to illustration 16.4
1 Following the procedure described in Section 15, remove the front
axle hub and bearing assembly.
2 Remove the disc brake splash shield.
3 If the right side axle is being removed, follow the procedure described in Section 17 and remove the front axle shift motor.
4 Slide the axle straight out of the axle housing (see illustration).
Right side intermediate axle
Refer to illustration 16.7
5 Remove the right side outer axle (see above Steps).
6 Remove the differential cover (see the differential lubricant changing procedure in Chapter 1 ).
7 Remove the intermediate shaft retaining clip in the differential case
(see illustration).
8 Slide the intermediate shaft out of the axle housing.
U-joint overhaul
Single cardan design
Refer to illustrations 16.9a and 16.9b
9 Follow the U-joint replacement procedure in Section 13, but note
that the snap-rings are inboard of the yoke ears and fit into grooves
in the bearing caps (see illustration). They are removed by driving them
out with a screwdriver (see illustration).
Double offset (constant velocity) design
Refertoillustrations 16.1 la, 16.1 lb, 16.12a, 16.12b, 16.13, 16.14,
16.15a, 16 · 15b' 16.18 and 16.19
16.9a
Exploded view of the front axleshaft U-joint assembly
16.7
16.9b
The right side intermediate axleshaft is held i n the
differential by a retaining clip
Push the snap-rings out of the groove i n the
bearings with a small screwdriver
U-Jol"'
I
The Motor Manual Guy
Chapter 8
8-13
Clutch and drivetrain
2
16.1 1a
Exploded view of the double offset (CV) joint
1 Clamps
2 Joint assembly
3 Spacer ring
Note: The constant velocity outer front axle joint is n o t repairable if i t becomes worn, noisy or breaks, the entire joint must be replaced.
The joint can and should, however, be disassembled, cleaned and
repacked with grease in the event o f a boot failure.
1 0 Cut both boot retaining clamps and discard them. Slide the boot
back on the axleshaft.
1 1 Mount the axleshaft in a vise. The jaws of the vise must be lined
with wood or rags to avoid damage to the axle. Using a hammer and
a brass punch positioned on the inner race, knock the joint off the axleshaft (see illustrations).
12 Remove the axleshaft from the vise. Place the joint assembly in
the vise, with the stub axle pointing down. Again, wood or rags must
line the vise jaws to prevent marring the stub axle surface. Tap the
inner race with the brass punch to angle it far enough to allow a ball
bearing to be removed (see illustration). Repeat this until all the balls
are removed. If the balls are stuck, a screwdriver can be used to pry
them from the cage (see illustration).
1 3 With all of the balls removed, tilt the inner race and cage assembly
90°, align the cage windows with the outer race (joint housing) lands
and remove the assembly from the outer race (see illustration).
4 Retaining ring
5 Boot
6 Axleshaft
16.1 1b
Dislodge the CV joint assembly with a brass punch and
hammer (be careful not to let the joint fall!)
8
16.12a Tilt the inner race far enough
to allow ball removal - a brass punch
can be used if the inner race is difficult
to move
16.12b If necessary, pry the ball
bearings out with a screwdriver
16.13 Tilt the inner race and cage
90-degrees, then align the windows in
the cage with the lands and rotate the
inner race up and out of the outer race
The Motor Manual Guy
8-14
16.14 Align the inner race lands with
the cage windows and rotate the inner
race out of the cage
Chapter 8
Clutch and drivetrain
Check the inner race lands and
grooves for pitting and score marks
16.1 Sa
14 Align the inner race lands with the cage windows and rotate the inner
race out of the cage (see illustration).
15 Wash all of the components in solvent and blow them dry with compressed air, if available. Inspect the cage and races for pitting, score
marks, cracks and other signs of wear and damage (see illustration).
Shiny, polished spots are normal and don't affect CV joint operation (see
illustration).
16 Install the inner race in the cage by reversing the technique described
in Step 14.
17 Install the inner race and cage assembly in the outer race by reversing
the removal method used in Step 13. The small diameter of the cage must
face out and the stopping groove in the inner race must face in.
18 Press the balls into the cage windows (see illustration).
19 Pack the CV joint assembly with half of the lubricant supplied in the
boot/joint kit through the innersplined hole. Force the grease into the bearing by inserting a wooden dowel through the splined hole and pushing it to
the bottom of the joint (see illustration). Repeat this procedure until the
joint is thoroughly packed (the other half of the grease is to be placed in the
boot).
20 Wrap the axleshaft splines with tape to avoid damaging the boot.
Place the small boot clamp in the groove in the small end of the boot, then
slide the boot onto the axleshaft. Remove the tape and smear the remainder of the grease into the boot.
16.18 Align the cage windows and the inner and outer race
grooves, then tilt the cage and inner race to insert the balls
16.1 Sb Check the cage for cracks,
pitting and score marks (shiny spots are
normal and don't affect operation)
21 Install the replacement retaining ring and spacer ring on the shaft.
22 Slide the CV joint onto the shaft until the inner race contacts the inner
retaining ring.
23 Install the large boot clamp in its groove in the boot and slide the boot
over the outer race (joint housing).
24 Tighten both boot clamps.
Installation
25 Installation is the reverse of the removal procedure. If the intermediate axle was removed, use a new gasket on the differential cover and fill
the differential housing wrth the specified type of gear lubricant (see Chapter 1).
17
Front axle shift motor - check, removal and installation
Refer to illustrations 17.8, 17. 10a and 17.1Gb
1
Raise the front of the vehicle and support it securely on jackstands.
Check
2 Disconnectthe vacuum line from the shift motor and connect a handheld vacuum pump to the front port of the motor.
16.19 Apply grease through the splined hole, then insert
a wooden dowel into the hole and push down - the dowel
will force grease into the joint
The Motor Manual Guy
Chapter 8
Clutch and drivetrain
8-15
3 Apply vacuum to the motor and rotate the right front wheel t o ensure that the axle is fully disengaged. The shift motor should hold
vacuum for at least 3 0 seconds. If it leaks, replace it.
4 If the motor holds vacuum, connect the vacuum pump t o the rear
port on the shift motor. Plug the other ports and apply vacuum once
again. It should hold vacuum for 3 0 seconds also. If not, replace the
motor.
5 With vacuum still applied, remove the plug from the port where
the vacuum line t o the transfer case connects. Check for vacuum. If
vacuum is not present, continue on to the next step.
6 Rotate the right front wheel to ensure that the axle has shifted
completely. If it hasn't, remove the shift motor and check for freeness
of the sliding shift collar.
7 Inspect the vacuum harness from the shift motor to the transfer
case for kinks, cracks and other signs of damage. Check the vacuum
harness connectors for a good, tight fit on the vacuum ports.
Removal
8 Unplug the vacuum harness from the shift motor (see illustration).
9 Remove the shift motor housing-to-axle housing bolts and lift the
shift motor housing, motor and fork from the axle housing. Remove
all traces of old gasket material.
1 0 Mark the relationship of the shift fork to the housing to return it
to its original position upon reassembly (see illustration). Rotate the
shift motor and remove the shift fork and motor retaining snap-rings
(see illustration) by pushing them down with t w o screwdrivers. Pull
the motor out of the housing.
17.8 Unplug the vacuum harness connectors (1), then
remove the four bolts that retain the shift motor housing (2)
Installation
11 Remove the O-ring from the shift motor and install a new one if
the same motor is to be reinstalled.
12 Slide tile shift motor into the housing and install the shift fork, lining
up the previously applied match-marks. Install the snap-rings, making
sure they are completely seated in their grooves.
13 Liberally coat the shift collar and axlshaft splines with wheel bearing
grease. Engage the shift fork with the shift collar and set the assembly
into position on the axle housing. Be sure to use a new gasket. Install
the bolts and tighten them to the specified torque.
1 4 Connect the vacuum harness and check the front differential lubricant level (see Chapter 1 ).
17.10a Mark the relationship of the shift fork t o the
housing so it will be reinstalled correctly
1 8 Front axle assembly - removal and installation
Note: This procedure is applicable to both 4WD and 2 WD vehicles.
If you are working on a 2 WD vehicle, ignore references to rhe driveshaft, differential and shift motor.
Remo val
1 Loosen the front wheel lug nuts, raise the front of the vehicle and
support it securely on jackstands positioned under the frame rails.
Remove the front wheels.
2 Unbolt the front brake calipers and hang them out of the way with
don't let the calipers hang by the brake hose (see
pieces of wire
Chapter 9).
3 Remove the brake pads, anchor plates and brake discs (see Chapter 9).
4 Disconnect the vacuum harness from the front axle shift motor
(see Section 17).
5 Mark the relationship of the front driveshaft to the front differential
pinion shaft yoke, then disconnect the driveshaft from the yoke (see
Section 12). Discard the U-joint straps.
6 Disconnect the stabilizer bar link from the bracket on the axle (see
Chapter 10).
7 Disconnect the tie-rod and center link from the steering knuckle
arms (see Chapter 10). Position them out of the way and hang them
with pieces of wire from the underbody.
8 Unbolt the lower ends of the shock absorbers from the axle.
9 Remove the steering dampener (see Chapter 10).
1 0 Remove the ABS sensor (if equipped) (see Chapter 9 for general
information).
11 Position a hydraulic jack under the differential. If t w o jacks are
8
17.10b Remove the shift fork and motor retaining snaprings (arrow is pointing t o fork retaining snap-ring) and
slide the motor out of the housing
available, place one under the right side axle tube to balance the
assembly (4WD models). On 2WD models, position the jack in the
center of the axle.
12 Unbolt the upper and lower suspension arms from the axle (see
Chapter 10).
1 3 Slowly lower the assembly t o the ground.
The Motor Manual Guy
Chapter 8
8-16
Clutch and drivetrain
Installation
14 Installation is the reverse of the removal procedure. When raising
the axle into position, make sure the coil springs seat properly. Be sure
t o use new U-joint straps. For fasteners with specified torque values,
be sure they are tightened to the specified torque.
19
Rear axleshaft and bearing assembly
and installation
removal
Refer to illustrations 19.2, 19.3, 19.5a and 19.5b
Remo val
19.2 Unscrew the four brake backing plate nuts using a socket
on an extension passing through the hole i n the axle flange
1 Loosen the wheel lug nuts, raise the rear of the vehicle and support it securely on jackstands. Remove the wheel.
2 Remove the brake drum and brake backing plate retaining nuts (see
illustration).
3 Connect a slide hammer and adapter t o the axle flange and pull
the axle from the housing (see illustration).
4 If the bearing must be replaced, take the assembly to a dealer service department or a repair shop t o have the old bearing removed and
a new one pressed on. If a new bearing is installed, be sure to also
replace the outer axle seal (see next Step).
5 If the brake backing plate shows evidence of leaking differential
lubricant, the outer axleshaft seal should be replaced. Remove the seal
using the slide hammer with an internal puller jaw attachment (see illustration). Install the new seal using a seal driver or piece of pipe (see
illustration).
Installation
6 Wipe the bearing bore in the axle housing clean. Pack the bearing
with wheel bearing grease and apply a thin coat of grease t o the outer
surface of the bearing.
7 Smear the lips of the inner seal with grease, then guide the axleshaft straight into the axle housing, being careful not to damage the
seal.
8 lnstall the brake backing plate nuts, tightening them to the specified
torque. Slide the brake drum over the axle flange.
9 lnstall the wheel and lug nuts, tightening the lug nuts securely.
Lower the vehicle and tighten the lug nuts t o the torque specified in
Chapter 1.
19.3
Pull the axle from the housing using a slide hammer
and axle flange adapter
INNER
SEAL
SEAL
INSTALLER
TOOL
SUPPOIU
TUBE
)
PLATE/~
19.5b Lubricate the seal lip, then drive the seal into position
Remove the inner axle seal from the housing using
a slide hammer and internal puller jaw attachment
19.5a
with an installation tool or a piece of pipe with an outside
diameter slightly smaller than the outside diameter of the seal
The Motor Manual Guy
Chapter 8
20
Clutch and drivetrain
Rear axle assembly - removal and installation
1 Loosen the rear wheel lug nuts, raise the vehicle and support it
securely on jackstands placed underneath the frame. Remove the
wheels.
2 Support the rear axle assembly with a floor jack placed underneath
the differential.
3 Remove the shock absorber lower mounting nuts and compress
the shocks to get them out of the way (see Chapter 10).
4 Disconnect the driveshaft from the differential pinion shaft yoke
and hang the rear of the driveshaft from the underbody with a piece
of wire (see Section 12).
5 Unbolt the stabilizer bar from the stabilizer bar link, if so equipped
(see Chapter 10).
6 Disconnect the parking brake cables from the equalizer (see Chap-
8-17
ter 9). Disconnect the height sensing proportioning valve control rod
from the axle housing (Comanche models only).
7 Disconnect the flexible brake hose from the junction block on the
rear axle housing. Plug the end of the hose or wrap a plastic bag tightly
around it to prevent excessive fluid loss and contamination.
8 Remove the U-bolt nuts from the leaf spring tie plates (see Chapter 10).
9 Raise the rear axle assembly slightly, then unbolt the springs from
the shackles (see Chapter 10) and lower the rear ends of the springs
t o the floor (only on models with the axle housing mounted above the
spring).
1 0 Lower the jack and move the axle assembly out from under the
vehicle.
11 Installation is the reverse of the removal procedure. Be sure to
tighten the U-bolt nuts and the U-joint strap bolts to the specified
torque.
s
The Motor Manual Guy
Chapter 9
Brakes
Contents
Disc brake pads
replacement
3
Drum brake shoes
replacement
6
Front wheel bearing service
See Chapter
1
General information
Height sensing proportioning valve
general information . . . 16
Master cylinder
removal, overhaul and installation
8
Power brake booster
check, removal and installation
12
Parking brake
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . 13
Parking brake cables
replacement
14
Wheel cylinder
removal, overhaul and installation
7
2
Anti-lock brake system (ABS) - general information
Brake disc
inspection, removal and installation
5
See Chapter 1
Brake fluid level check
Brake hoses and lines
inspection and replacement
10
Brake light switch
replacement
17
removal and installation
15
Brake pedal
Brake system bleeding
11
Brake system check
See Chapter 1
Combination valve
check and replacement
9
Disc brake caliper
removal, overhaul and installation
4
Specifications
General
Brake fluid type
See Chapter 1
Disc brakes
Disc standard thickness
0.88 in (22.45 mm)
Disc minimum thickness*
0.81 5 in (20.7 mm)
Disc run out (maximum)
0.004 in (0.1 0 mm)
Brake pad minimum thickness
See Chapter 1
* Refer to marks cast in the rotor (they supersede information printed here}
Drum brakes
10.000 in (254 mm)
Drum standard diameter
Drum maximum diameter*
10.060 in (255.5 mm)
Minimum brake lining thickness
See Chapter 1
* Refer to marks cast in the drum (they supersede information printed here)
Torque specifications
Brake pedal pivot pin nut
Manual transmission
Automatic transmission
Power brake booster pushrod nuts
lnnernut . . . . . . . . . . . . . . . . . .
Outer nut
....................
.....................................
Power brake booster mounting nuts
Master cylinder mounting nuts . . . . . . . . . . . . . . . . . . . . . . .
Caliper mounting pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caliper anchor plate bolts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake hose-to-caliper inlet fitting bolt
Wheel cylinder mounting bolts
Brake backing plate bolts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ft-lbs (unless otherwise indicated)
20
26
25
75 in-lbs
30
15
30
77
23
9 0 in-lbs
32
The Motor Manual Guy
Chapter 9
1
Brakes
9- 1
Power brake booster (non-ABS models)
General information
Refer to illustration 7.2
The vehicles covered by this manual are equipped with hydraulically
operated front and rear brake systems. The front brakes are disc type
and the rear brakes are drum type. Both the front and rear brakes are
self adjusting. The front disc brakes automatically compensate for pad
wear, while the rear drum brakes incorporate an adjustment mechanism
which is activated as the brakes are applied when the vehicle is driven
reverse.
The power brake booster, utilizing engine manifold vacuum and atmospheric pressure to provide assistance to the hydraulically operated
brakes, is mounted on the firewall in the engine compartment.
Parking brake
The parking brake operates the rear brakes only, through cable actuation. It's activated by a lever mounted in the center console
(Cherokee models) or a pedal mounted on the left side kick panel (Comanche models).
Service
Hydraulic system
The hydraulic system consists of t w o separate circuits (see illustration). The master cylinder has separate reservoirs for the t w o circuits
and in the event of a leak or failure in one hydraulic circuit, the other
circuit will remain operative. A visual warning of circuit failure or air
in the system is given by a warning light activated by displacement
of the piston in the pressure differential switch portion of the combination valve from its normal "in balance" position.
Combination valve
A combination valve, located in the engine compartment below the
master cylinder, consists of three sections providing the following functions. The metering section limits pressure to the front brakes until
a predetermined front input pressure is reached and until the rear brakes
are activated. There is no restriction at inlet pressures below 3 psi,
allowing pressure equalization during non-braking periods. The proportioning section proportions outlet pressure to the rear brakes after a
predetermined rear input pressure has been reached, preventing early
rear wheel lock-up under heavy brake loads. The valve is also designed
to assure full pressure to one brake system should the other system
fail. The pressure differential warning switch incorporated into the combination valve is designed to continuously compare the front and rear
brake pressure from the master cylinder and energize the dash warning
light in the event of either a front or rear brake system failure. The
design of the switch and valve are such that the switch will stay in
the Warning position once a failure has occurred. The only way to turn
the light off is to repair the cause of the failure and apply a brake pedal
force of 450 psi.
After completing any operation involving disassembly of any part
of the brake system, always test drive the vehicle to check for proper
braking performance before resuming normal driving. When testing the
brakes, perform the tests on a clean, dry flat surface. Conditions other
than these can lead t o inaccurate test results.
Test the brakes at various speeds with both light and heavy pedal
pressure. The vehicle should stop evenly without pulling to one side
or the other. Avoid locking the brakes because this slides the tires and
diminishes braking efficiency and control of the vehicle.
Tires, vehicle load and front-end alignment are factors which also
affect braking performance.
2
Anti-lock brake system (ABS)
- general information
Refer to illustrations 2.2, 2.4 and 2.5
The anti-lock brake system was introduced in 1989 and is designed
to maintain vehicle steerability, directional stability and optimum
deceleration under severe braking conditions and on most road surfaces. It does so by monitoring the rotational speed of each wheel and
controlling the brake line pressure t o each wheel during braking. This
prevents the wheel from locking-up and provides maximum vehicle
controllability.
Components
Actuation assembly
The actuation assembly consists of the master cylinderipower
9
1.2
Schematic of the brake hydraulic system (non-ABS)
1 Master cylinder
2 Combination valve
l
3 Disc brake caliper
4 Wheel cylinder
j
The Motor Manual Guy
9-2
Chapter 9
booster unit, an electric booster pump and motor assembly (which contains an accumulator), a pressure modulator and an accumulator and
pressure switch assembly (see illustration).
a) The electric pump provides hydraulic pressure to charge the
accumulator, which supplies pressure to the braking system. The
pump and accumulator are mounted t o the firewall on the righthand side.
b) The pressure modulator mounts to the side of the master cylinder
and power booster unit and modulates brake line pressure during ABS operation. The valve body contains three valves - one
for each front wheel and one for the both of the rear wheels
combined.
Wheel sensors
These sensors are located at each wheel and generate small electrical pulsations when the toothed sensor rings are turning, sending
a signal to the electronic controller, indicating wheel rotational speed.
The front wheel sensors (see illustration) are mounted to the steering knuckles in close relationship to the tone wheels, which are integral
with the front axleshafts.
The rear wheel sensors bolt to the drum brake backing plates (see
illustration). The tone wheels are integral with the rear axleshafts.
Electronic controller
The electronic controller is mounted under the rear seat and is the
"brain" for the ABS system. The function of the control module consisting of microprocessors, a mercury switch and the related circuits
needed for their operation - is to accept and process information
received from the wheel speed sensors in conjunction with the signal
BOOSTER PUMP AND MOTOR
Brakes
from the internal mercury switch to control the hydraulic line pressure,
avoiding wheel lock-up. The controller also constantly monitors the
system, even under normal driving conditions, to find faults within the
system.
If a problem develops within the system, a yellow or red light will
glow on the dashboard. A diagnostic code will also be stored in the
controller, which, when retrieved by a service technician, will indicate
the problem area or component.
Diagnosis and repair
If a dashboard warning light comes on and stays on while the vehicle
is in operation, the ABS system requires attention. Although a special
electronic ABS diagnostic tester is necessary to properly diagnose the
system, the home mechanic can perform a few preliminary checks
before taking the vehicle t o a dealer who is equipped with this tester.
a) Check the brake fluid level in the reservoir.
b) Lift up the rear seat cushion and check that the controller elecrical
connector is securely connected.
c) Check the electrical connectors at the pump motor, acccumulator
pressure switch and pressure modulator.
d) Check the fuses.
e) Follow the wiring harness t o each wheel and check that all connections are secure and that the wiring is not damaged.
If the above preliminary checks do not rectify the problem, the vehicle
should be diagnosed by a dealer service department. Due to the rather
complex nature of this system and the high operating pressures involved, all actual repair work must be done by a dealer service department.
MASTER CYLINDER/POWER BOOSTER
BOOST PRESSURE SWITCH (IN
MODULATOR)
PRESSURE
MODULATOR
PROPORTIONING
VAL VE/DIFFERENTIAL
SWITCH
ECU
SENSOR
CONNECTORSiWIRES
LEFT
FRONT
SENSOR
2.2
RIGHT
REAR WHEEL
SENSORS
Fta:>NT
SENSOR
Schematic of the brake hydraulic system and control circuit - ABS-equipped models
j
The Motor Manual Guy
Chapter 9
9-3
Brakes
(j)
SENSOR
ADJUSTING BOLT
I
I
1
l/ I)
I
I II
2.4
Front wheel sensor details
3 Disc brake pads - replacement
Refer to illustrations 3.5 and 3.6a through 3.6k
Warning: Disc brake pads must be replaced on both front wheels at
the same time
never replace the pads on only one wheel. Also, the
dust created by the brake system may contain asbestos, which is
harmful to your health. Never blow it out with compressed air and don't
inhale any of it. An approved filtering mask should be worn when working on the brakes. Do not, under any circumstances, use petroleumbased solvents to clean brake parts. Use brake system cleaner or clean
brake fluid only!
Note: When servicing the disc brakes, use only high quality, nationally
recognized name brand pads.
1 Remove the cover from the brake fluid reservoir.
2 Loosen the wheel lug nuts, raise the front of the vehicle and support
It securely on jackstands.
3.5 Using a large C-clamp, push the
piston back into the caliper bore - note
that one end of the clamp is on the flat
area on the backside of the caliper and
the other end (screw end) is pressing
against the outer brake pad
\/
~A_///4
W{{{(((
@tl!!&1 ~/
/
2.5
Rear wheel sensor details
3 Remove the front wheels. Work on one brake assembly at a time,
using the assembled brake for reference if necessary.
4 Inspect the brake disc carefully as outlined in Section 5. If machining is necessary, follow the information in that Section to remove the
disc, at which time the pads can be removed from the calipers as well.
5 Push the piston back into the bore to provide room for the new
brake pads. A C-clamp can be used to accomplish this (see illustration).
As the piston is depressed t o the bottom of the caliper bore, the fluid
in the master cylinder will rise. Make sure it doesn't overflow. If necessary, siphon off some of the fluid.
6 Follow the accompanying illustrations, beginning with 3.6a, for
the actual pad replacement procedure. Be sure t o stay in order and
read the caption under each illustration.
7 When reinstalling the caliper, be sure to tighten the mounting pins
to the specified torque. After the job has been completed, firmly depress
the brake pedal a few times to bring the pads into contact with the disc.
8 Check for fluid leakage and make sure the brakes operate normally
before driving in traffic.
3.6a Before removing the caliper, wash
off all traces of brake dust with brake
system cleaner
3.6b
Using an Allen wrench, unscrew
the t w o caliper mounting pins
The Motor Manual Guy
9-4
.
Chapter 9
Brakes
3.6c Swing the upper end of the
caliper out of the anchor plate, then
remove the caliper completely. Take this
opportunity t o check for fluid leakage
around the caliper piston boot, which
would indicate the need t o overhaul the
calipers (see Section 4)
3.6d Once the caliper is removed from
the anchor plate, hang i t from the coil
spring with a piece of wire - DON'T let
i t hang by the brake hose!
3.6e Pry downward on the lower
anti-rattle clip and remove the
outer brake pad
3.6f Pull the anti-rattle clips away
from the pad with your index fingers
and force the inner brake pads out
with your thumbs
3.6g Before installing the brake pads,
clean the sliding surfaces on the caliper
and anchor plate and apply a thin coat
of high-temperature grease t o the
anchor plate in the area shown
3.6h Position the anti-rattle clips on
the anchor plate and install the
inner brake pad
3.6i Place the lower end of the outer
pad on the anchor plate and push i t
down against the anti-rattle clip, then lift
up on the upper anti-rattle clip and
swing the pad into position
3.6j Engage the notch i n the lower end
of the caliper with the anchor plate,
then rotate it over the pads
3.6k Lubricate the mounting pins with
high-temperature grease, push them into
the caliper and tighten them to the
specified torque
The Motor Manual Guy
Chapter 9
4 Disc brake caliper - removal, overhaul and installation
Warning: Dust created by the brake system may contain asbestos,
which is harmful to your health. Never blow it out with compressed
air and don't inhale any of it. An approved filtering mask should be
worn when working on the brakes. Do not, under any circumstances,
use petroleum-based solvents to clean brake parts. Use brake system
cleaner or clean brake fluid only!
Note: If an overhaul is indicated (usually because of fluid leakage) explore all options before beginning the job. New and factory rebuilt
calipers are available on an exchange basis, which makes this job quite
easy. If it's decided to rebuild the calipers, make sure a rebuild kit is
available before proceeding. Always rebuild the calipers in pairs never
rebuild just one of them.
Removal
Refer to illustration 4.4
1 Remove the cover from the brake fluid reservoir, siphon off twothirds of the fluid into a container and discard it.
2 Loosen the wheel lug nuts, raise the front of the vehicle and support
Brakes
9-5
it securely on jackstands. Remove the front wheels.
3 Bottom the piston in the caliper bore (see illustration 3.5).
4 Note: Do not remove the brake hose from the caliper if you are
only removing the caliper. Remove the brake hose inlet fitting bolt and
detach the hose (see illustration). Have a rag handy t o catch spilled
fluid and wrap a plastic bag tightly around the end of the hose to prevent
fluid loss and contamination.
5 Unscrew the t w o caliper pins and detach the caliper from the vehicle (refer to Section 3 if necessary).
Overhaul
Refer to illustrations 4.7, 4.Ba, 4.Bb, 4.9, 4.10, 4.15 and 4.16
6 Clean the exterior of the caliper with brake cleaner or clean brake
fluid. Never use gasoline, kerosene or petroleum-based cleaning
solvents. Place the caliper on a clean workbench.
7 Position a wooden block or several shop rags in the caliper as a
pad, then use compressed air t o remove the piston from the caliper
(see illustration). Use only enough air pressure to ease the piston out
of the bore. If the piston is blown out, even with the cushion in place,
it may be damaged. Warning: Neverplace your fingers in front of the
piston in an attempt to catch or protect it when applying compressed
air, as serious injury could occur.
8 Carefully pry the dust boot out of the caliper bore (see illustrations).
4.4 Location of the brake hose inlet fitting bolt (arrow) - when
reinstalling the bolt, be sure t o use new sealing washers on each
side of the fitting to prevent fluid leaks
4.7 With the caliper padded t o catch the piston, use
compressed air t o force the piston out of its bore - make
sure your hands or fingers are not between the
piston and caliper frame!
,.~r,~ ~
MOUNTING
PIN
CALIPER
INNER AND
OUTER BUSHINGS
I
i
fl))J(11~
PISTON
,
SEAL
l__
--~
DUST
BOOT
~~
4.8 a
Carefully pry the dust boot out of the caliper
4.8b
Exploded view of the disc brake caliper
9
The Motor Manual Guy
9-6
Chapter 9
4.9 The piston seal should be removed with a plastic or
wooden tool to avoid damage to the bore and seal groove.
A pencil will do the job
9
Using a wood or plastic tool, remove the piston seal from the
groove in the caliper bore (see illustration). Metal tools may cause bore
damage.
1 0 Remove the caliper bleeder screw, then remove and discard the
mounting pin bushings (see illustration). Discard all rubber parts.
1 1 Clean the remaining parts with brake system cleaner or clean brake
fluid, then blow them dry with compressed air.
12 Carefully examine the piston for nicks and burrs and loss of plating.
If surface defects are present, the parts must be replaced.
13 Check the caliper bore in a similar way. Light polishing with crocus
cloth is permissible t o remove light corrosion and stains. Discard the
caliper pins if they're corroded or damaged.
1 4 When assembling the caliper, lubricate the piston bore and seal
with clean brake fluid. Position the seal in the caliper bore groove.
15 Lubricate the piston with clean brake fluid, install it squarely in
the bore and apply pressure to bottom it in the caliper (see illustration).
16 Stretch the dust boot over the groove in the piston, then carefully
seat it in the caliper bore (see illustration).
4.1 5 When installing the piston, make sure i t doesn't
become cocked in the caliper bore while pushing it down
Brakes
4.10 Grab the ends of the mounting pin bushings with
needle-nose pliers and, using a twisting motion. push
them through the caliper ears
17 Install the bleeder screw.
18 lnstall new inner and outer mounting pin bushings.
Installation
19 Inspect the caliper pins for excessive corrosion, replacing them
if necessary.
2 0 Clean the sliding surfaces of the caliper and the anchor plate (see
illustration 3.6g).
21 lnstall the caliper as described in illustration 3.6j and 3.6k.
22 lnstall the brake hose and inlet fitting bolt, using new copper
washers, then tighten the bolt to the specified torque.
23 If the line was disconnected, be sure to bleed the brakes (see Section 11).
2 4 lnstall the wheels and lower the vehicle.
25 After the job has been completed, firmly depress the brake pedal
a few times to bring the pads into contact with the disc.
26 Check brake operation before driving the vehicle in traffic.
4.16 If the correct seal driver tool isn't available. a drift
punch can be used to tap around the the circumference
until the dust boot is seated
The Motor Manual Guy
Chapter 9
5.4a Use a dial indicator to check disc runout - if the
reading exceeds the specified allowable runout limit, the
disc will have to be machined or replaced
5
Brake disc - inspection, removal and installation
Inspection
Refer to illustrations 5.4a, 5.4b, 5.5a and 5.5b
1 Loosen the wheel lug nuts, raise the vehicle and support it securely
on jackstands. Remove the wheel.
2 Remove the brake caliper as described in Section 3. It's not
necessary t o disconnect the brake hose. After removing the caliper
mounting pins, suspend the caliper out of the way with a piece of wire
as shown in illustrations 3.6d. Don't let the caliper hang by the hose
and don't stretch or twist the hose. Reinstall t w o of the lug nuts to
hold the disc in place (4WD models only).
3 Visually check the disc surface for score marks and other damage.
Light scratches and shallow grooves are normal after use and may not
over
always be detrimental to brake operation, but deep score marks
0.01 5-inch (0.38 mm) - require disc removal and refinishing by an
automotive machine shop. Be sure to check both sides of the disc.
If pulsating has been noticed during application of the brakes, suspect
disc runout. Be sure to check the wheel bearings to make sure they're
properly adjusted.
9-7
Brakes
5.4b
Using a swirling motion, remove the glaze from the
disc surface with sandpaper or emery cloth
4 To check disc runout, place a dial indicator at a point about 112-inch
from the outer edge of the disc (see illustration). Set the indicator to
zero and turn the disc. The indicator reading should not exceed the
specified allowable runout limit. If it does, the disc should be refinished
by an automotive machine shop. Note: Professionals recommend resurfacing of brake discs regardless of the dial indicator reading (to produce a smooth, flat surface that will eliminate brake pedal pulsations
and other undesirable symptoms related to questionable discs). A t the
very least, if you elect not to have the discs resurfaced, deglaze them
with sandpaper or emery cloth (use a swirling motion to ensure a nondirectional finish) (see illustration).
5 The disc must not be machined t o a thickness less than the specified minimum refinish thickness. The minimum (or discard) thickness
is cast into the inside of the disc (see illustration). The disc thickness
can be checked with a micrometer (see illustration).
Removal
6 If the vehicle is a 4WD, remove the t w o lug nuts that were installed
to hold the disc in place, then slide the disc off the hub. If the vehicle
is a 2WD, refer to Chapter 1, Front wheel bearing check, repack and
adjustment for the hubldisc removal procedure.
9
5.5a
The minimum thickness is cast into the inside
of the disc
5.5b
Use a micrometer to measure disc thickness at
several points
The Motor Manual Guy
Chapter 9
9-8
Installation
7 On 2WD models, install the disc and hub assembly and adjust the
wheel bearing (see Chapter 1 ). If the disc has been machined on a 2WD
model, thoroughly wash out the hub with solvent, then clean and
repack the wheel bearing (see Chapter 1 ). On 4WD models simply place
the disc over the wheel studs on the hub.
8 Install the caliper and brake pad assembly over the disc and position
it on the steering knuckle (refer to Section 4 for the caliper installation
procedure, if necessary). Tighten the caliper mounting pins to the specified torque.
9 Install the wheel, then lower the vehicle to the ground. Depress
the brake pedal a few times to bring the brake pads into contact with
the disc. Bleeding of the system will not be necessary unless the brake
hose was disconnected from the caliper. Check the operation of the
brakes carefully before placing the vehicle into normal service.
Brakes
the parking brake is completely released, then apply some penetrating
oil at the hub-to-drum joint. Allow the oil to soak in and try to pull the
drum off. If the drum still cannot be pulled off, the brake shoes will
have to be retracted. This is accomplished by first removing the plug
from the backing plate. With the plug removed, pull the lever off the
adjusting star wheel with one narrow screwdriver while turning the
adjusting wheel with another narrow screwdriver, moving the shoes
away from the drum (see illustration 6.7, if necessary). The drum
should now come off.
5 Before reinstalling the drum it should be checked for cracks, score
marks, deep scratches and hard spots, which will appear as small discolored areas. If the hard spots cannot be removed with fine emery
FRONT OF VEHICLE
~
6
Drum brake shoes
ANCHOR PIN
PLATE
replacement
Refer to illustrations 6.4a through 6.4x, 6.5, and 6.8
Warning: Drum brake shoes must be replaced on both wheels at the
same time - never replace the shoes on only one wheel. Also, the
dust created by the brake system may contain asbestos, which is
harmful to your health. Never blow it out with compressed air and don't
inhale any of it. An approved filtering mask should be worn when working on the brakes. Do not, under any circumstances, use petroleumbased solvents to clean brake parts. Use brake s ystem cleaner or clean
brake fluid only!
Caution: Whenever the brake shoes are replaced, the retracting and
hold-down springs should also be replaced. Due to the continuous
heating/cooling cycle that the springs are subjected to, they lose their
tension over a period of tirne and may allow the shoes to drag on the
drum and wear at a much faster rate than normal. When replacing the
rear brake shoes, use only high quality nationally recognized brandname parts.
1 Loosen the wheel lug nuts, raise the rear of the vehicle and support
it securely on jackstands. Block the front wheels to keep the vehicle
from rolling.
2 Release the parking brake.
3 Remove the wheel. Note: All four rear brake shoes must be replaced
at the same tirne, but to avoid mixing up parts, work on only one brake
assembly at a tirne.
4 Follow the accompanying illustrations (6.4a through 6.4x) for the
inspection and replacement of the brake shoes. Be sure to stay in order
and read the caption under each illustration. Note: If the brake drum
cannot be easily pulled off the axle and shoe assembly, make sure that
6.4b Before removing any internal drum brake
components, wash them off with brake cleaner and allow
them to dry - position a drain pan under the brake t o
catch the residue - DO NOT USE COMPRESSED AIR TO
BLOW THE BRAKE DUST FROM THE PARTS!
PARKING
BRAKE
LINK
LEVER
SPRING
PARKING
BRAKE
CABLE
SOCKET
ADJUSTING
LEVER
ADJUSTING
SCREW
6.4a Rear drum brake components - left side shown
6.4c
Pull outward on the adjuster lever and turn the star
wheel t o retract the brake shoes
The Motor Manual Guy
Chapter 9 Brakes
6.4d Pull back on the self-adjuster
cable and push the adjusting lever
toward the rear, unhooking i t from
the secondary brake shoe
6.4g Remove the secondary shoe
retracting spring and cable guide from
the secondary shoe
6.4e Remove the primary and
secondary shoe retracting springs - the
spring removal tool shown here can be
purchased at most auto parts stores
and greatly simplifies this step
6.4h
Remove the primary shoe hold
down spring and pin . . .
9-9
6.4f Remove the self-adjuster cable
and anchor pin plate from the anchor pin
6.4i . . . then lift the primary shoe and
adjusting screw from the backing plate
9
6.4j
Remove the parking brake link
6.4k Remove the secondary shoe holddown spring and pin then lift the shoe
from the backing plate - pry the
parking brake lever retaining clip
off of the pivot pin . . .
6.41 . . . then separate the lever from
the secondary shoe - be careful not to
lose the spring washer
The Motor Manual Guy
Chapter 9
9-10
Brakes
Lubricate the brake shoe contact
areas (arrows) with high
temperature grease
6.4n Attach the new shoe t o the
parking brake lever, install the spring
washer and retaining clip on the pivot
pin then crimp the clip closed with
a pair of pliers
6.40 Install the secondary shoe and
hold down spring t o the backing plate,
then position the end of the parking
brake link into the notch (arrow)
6.4p
Lubricate the adjusting screw
with high temperature
multi-purpose grease
6.4q Place the primary shoe against
the backing plate, then install the holddown spring - make sure the parking
brake strut and wheel cylinder pushrods
engage in the brake shoe slots
6.4r Install the anchor pin plate
6.4s
...
6.4t Hook the end of the secondary
shoe retractor spring through the cable
guide and into the hole in the shoe, then
stretch the spring over the anchor pin
6.4m
and the self-adjuster cable
...
6.4u Install the primary shoe retractor
spring - the tool shown here is
available at most auto parts stores and
makes this step much easier and safer
The Motor Manual Guy
Chapter 9
Hook the adjuster lever spring
into the hole at the bottom of the
primary shoe
Brakes
6.4w Hook the adjuster lever spring
and cable into the adjuster lever and pull
the cable down and t o the rear, inserting
the hook on the lever into the hole
in the secondary shoe
cloth or if any of the other conditions listed above exist, the drum must
be taken to an automotive machine shop t o have it turned. Mote: Professionals recommend resurfacing the drums whenever a brake job is
done. Resurfacing will eliminate the possibility of out-of-round drums.
If the drums are worn so much that they can't be resurfaced without
exceeding the maximum allowable diameter (stamped into the drum)
(see illustration), then new ones will be required. At the very least,
if you elect not to have the drums resurfaced, remove the glazing from
the surface with medium-grit emery cloth using a swirling motion.
6 Once the new shoes are in place, install the drums on the axle
flanges. Remove the rubber plugs from the brake backing plates.
7 Insert a narrow screwdriver or brake adjusting tool through the
adjustment hole and turn the star wheel until the brakes drag slightly
as the drum is turned (see illustration).
8 Turn the star wheel in the opposite direction until the drum turns
freely. Keep the adjuster lever from contacting the star wheel or it won't
turn. This can be done by pushing on it with a narrow screwdriver.
9 Repeat the adjustment on the opposite wheel and install the backing plate plugs.
9-11
Wiggle the assembly t o ensure
the shoes are centered on the
backing plate
10 Mount the wheel, install the lug nuts, then lower the vehicle.
Tighten the lug nuts t o the torque specified in Chapter 1.
1 Make a number of forward and reverse stops to allow the brakes
to further adjust themselves.
1 2 Check brake operation before driving the vehicle in traffic.
7
Wheel cylinder - removal, overhaul and installation
Note: If an overhaul is indicated (usually because of fluid leakage or
sticky operation) explore all options before beginning the job. New
wheel cylinders are available, which makes this job quite easy. If it's
decided to rebuild the wheel cylinder, make sure that a rebuild kit is
available before proceeding. Never overhaul only one wheel cylinder always rebuild both of them at the same time.
9
___ ,
MOVE HANDLE
DOWNWARD
TO EXPAND
BRAKE SHOES
6.5
The maximum allowable drum diameter is cast into
the drum
6.7 Using a screwdriver or brake adjuster tool, turn the adjuster
wheel in the direction shown until the shoes drag on the brake
drum; then, insert a small screwdriver through the backing plate
to move the adjuster lever away from the adjuster wheel and turn
the wheel in the opposite direction until the drum turns freely
The Motor Manual Guy
Chapter 9
9-12
Brakes
7.4 Completely loosen the brake line fitting (1 ), then
remove the t w o wheel cylinder mounting bolts (2)
(one is barely visible in this photo)
7.7
Exploded view of the wheel cylinder
1 Piston and boot
2 Wheel cylinder body
4 Expander assembly
5 Bleeder screw
3 Piston CUl)S
Removal
Refer to illustration 7.4
1 Raise the rear of the vehicle and support it securely on jackstands.
Block the front wheels to keep the vehicle from rolling.
2 Remove the brake shoe assembly (see Section 6).
3 Remove all dirt and foreign material from around the wheel cylinder.
4 Completely loosen the brake line fitting (see illustration). Don't pull
the brake line away from the wheel cylinder.
5 Remove the wheel cylinder mounting bolts (see illustration 7.4).
6 Detach the wheel cylinder from the brake backing plate and place
it on a clean workbench. Immediately plug the brake line to prevent
fluid loss and contamination. Note: If the brake shoe linings are contaminated with brake fluid, install new brake shoes.
Overhaul
Refer to illustration 7.7
Remove the bleeder screw, piston cups, pistons, boots and expander assembly from the wheel cylinder body (see illustration).
8 Clean the wheel cylinder with brake fluid or brake system cleaner.
Warning: Do not, under any circumstances, use petroleum based
solvents to clean brake parts!
9 Use compressed air to remove excess fluid from the wheel cylinder
and to blow out the passages.
10 Check the cylinder bore for corrosion and score marks. Crocus cloth
can be used to remove light corrosion and stains, but the cylinder must
be replaced with a new one if the defects cannot be removed easily,
or if the bore is scored.
11 Lubricate the new cups with brake fluid.
12 Assemble the wheel cylinder components. Make sure the recessed
sides of the cups face in.
7
Removal
Refer to illustration 8.2
1 Place rags under the brake line fittings and prepare caps or plastic
bags to cover the ends of the lines once they are disconnected. Caution:
Brake fluid will damage paint. Cover all body parts and be careful not
to spill fluid during this procedure.
2 Loosen the tube nuts at the ends of the brake lines where they
enter the master cylinder. To prevent rounding off the flats on these
nuts, a flare-nut wrench, which wraps around the nut, should be used
(see illustration).
3 Pull the brake lines away from the master cylinder slightly and plug
the ends to prevent contamination.
4 Remove the t w o master cylinder mounting nuts and remove the
master cylinder from the vehicle.
5 Remove the reservoir cover, then discard any fluid remaining in
the reservoir.
lnstalla tion
13 Place the wheel cylinder in position and install the bolts.
14 Connect the brake line and tighten the fitting. Install the brake shoe
assembly.
15 Bleed the brakes (see Section 1 1).
16 Check brake operation before driving the vehicle in traffic.
8
Master cylinder
removal, overhaul and installation
Note: Before deciding to overhaul the master cylinder, investigate the
availability and cost of a new or factory rebuilt unit and also the availability of a rebuild kit. This procedure does not apply to models equipped
with ABS.
8.2
Unscrew the tube nuts from the master cylinder
use a flare-nut wrench (if one is available)
-
The Motor Manual Guy
Chapter 9
8.7 Use a Phillips head screwdriver to push the primary
piston into the cylinder, then remove the snap-ring with a
pair of snap-ring pliers
Brakes
9-13
8.8 Remove the primary piston assembly from the cylinder
Overhaul
Refer to illustrations 8.7, 8.8, 8.9, and 8. 13
6 Mount the master cylinder in a vise with the vise jaws clamping
on the mounting flange.
7 Remove the primary piston snap-ring by depressing the piston and
extracting the ring with a pair of snap-ring pliers (see illustration).
8 Remove the primary piston assembly from the cylinder bore (see
illustration). Discard it, since it can only be serviced as an assembly.
9 Reinstall the reservoir cover and remove the secondary piston
assembly from the cylinder bore by applying compressed air to the
secondary brake line port (see illustration).
1 0 lnspect the cylinder bore for corrosion and damage. If any corrosion
or damage is found, replace the master cylinder body with a new one,
as abrasives cannot be used on the bore.
1 1 Remove the seals, O-ring, piston spring and seal retainer from the
secondary piston. Discard them.
12 Clean the master cylinder body and secondary piston with clean
brake fluid or brake cleaner.
13 Assemble the O-rings, seals, piston spring and seal retainer to the
secondary piston (see illustration). Make sure the seal lips face away
from each other.
14 Lubricate the cylinder bore and primary and secondary piston
assemblies with clean brake fluid. Install the secondary piston assembly
into the cylinder.
15 Install the primary piston assembly in the cylinder bore, depress
it and install the snap-ring.
16 lnspect the reservoir cover and diaphragm for cracks and deformation. Replace it if it's damaged in any way.
17 Note: Whenever the master cylinder is removed, the complete
hydraulic system must be bled. The time required to bleed the system
can be reduced if the master cylinder is filled with fluid and bench bled
(refer to Steps 18 through 22) before the master cylinder is installed
on the vehicle.
1 8 Insert threaded plugs of the correct size into the cylinder outlet
holes and fill the reservoirs with brake fluid. The master cylinder should
be supported in such a manner that brake fluid will not spill during the
bench bleeding procedure.
1 9 Loosen one plug at a time, starting with the rear outlet port first,
and push the piston assembly into the bore to force air from the master
cylinder. To prevent air from being drawn back into the cylinder, the
appropriate plug must be replaced before allowing the piston to return
t o its original position.
2 0 Stroke the piston three or four times for each outlet to ensure that
all air has been expelled.
21 Since high pressure is not involved in the bench bleeding procedure,
an alternative to the removal and replacement of the plugs with each
stroke of the piston assembly is available. Before pushing in on the
8.9 Eject the secondary piston assembly by appling compressed
air to the secondary brake line port. While doing this, cover the
opening in the cylinder with a piece of wood t o serve as a
shield - only apply enough air pressure t o ease the piston out!
FRONT
SEAL
SECONDARY
SEAL
PISTON
RETAINER
I
REAR
O-RING
SEAL
PISTON
SPRING
8.13 Assembled view of the secondary piston - note
that the lips of the seals face away from each other
The Motor Manual Guy
9-14
Chapter 9
piston assembly, remove one of the plugs completely. Before releasing
the piston, however, instead of replacing the plug, simply put your
finger tightly over the hole to keep air from being drawn back into the
master cylinder. Wait several seconds for the brake fluid to be drawn
from the reservoir to the piston bore, then repeat the procedure. When
you push down on the piston it will force your finger off the hole, allowing the air inside to be expelled. When only brake fluid is being ejected
from the hole, replace the plug and go on to the other port.
2 2 Refill the master cylinder reservoir and install the diaphragm and
cover assembly.
Installation
23 Carefully install the master cylinder by reversing the removal steps,
then bleed the brakes (refer to Section 1 1).
9
Brakes
light when a jumper is connected t o ground, the warning light switch
portion of the combination valve is defective and the combination valve
must be replaced with a new one since the components of the combination valve are not individually serviceable.
Replacement
1 4 Place a container under the combination valve and protect all
painted surfaces with newspapers or rags.
1 5 Disconnect the hydraulic lines at the combination valve, using a
flare-nut wrench, if available. Plug the lines to prevent further loss of
fluid and to protect the lines from contamination.
1 6 Disconnect the electrical connector from the pressure differential
switch.
1 7 Remove the bolt holding the valve t o the mounting bracket and
remove the valve from the vehicle.
1 8 Installation is the reverse of the removal procedure.
19 Bleed the entire brake system.
Combination valve - check and replacement
Refer to illustration 9.
Check
1
Disconnect the wire connector from the pressure differential switch
(see illustration). Note: When unplugging the connector, squeeze the
side lock releases, moving the inside tabs away from the switch, then pull
up. Pliers may be used as an aid if necessary.
2 Using a jumper wir;,e, connect the switch wire to a good ground, such
as the engine block.
3 Turn the ignition key to the On position. The warning light in the instrument panel should light.
4 If the warning light does not light, either the bulb is burned out or the
electrical circuit is defective. Replace the bulb (refer to Chapter 12) or repair the electrical circuit as necessary.
5 When the warning light functions correctly, turn the ignition switch
off, disconnect the jumper wire and reconnect the wire t o the switch
terminal.
6 Make sure the master cylinder reservoirs are full, then attach a
bleeder hose to one of the rear wheel bleeder valves and immerse the
other end of the hose in a container partially filled with clean brake fluid.
7 Turn the ignition switch on.
8 Open the bleeder valve while a helper applies moderate pressure
to the brake pedal. The brake warning light on the instrument panel
should light.
9 Close the bleeder valve before the helper releases the brake pedal.
1 0 Reapply the brake pedal with moderate t o heavy pressure. The
brake warning light should go out.
11 Attach the bleeder hose to one of the front brake bleeder valves
and repeat Steps 8 through 10. The warning light should react in the
same manner as in Steps 8 and 10.
12 Turn the ignition switch off.
13 If the warning light did not come on in Steps 8 and 11, but does
9.1 Location of the combination valve - master cylinder
removed for clarity - the arrow shows the location of
the wire connector
10
Brake hoses and lines
inspection and replacement
Inspection
1 About every six months, with the vehicle raised and supported
securely on jackstands, the rubber hoses which connect the steel brake
lines with the front and rear brake assemblies should be inspected for
cracks, chafing of the outer cover, leaks, blisters and other damage.
These are important and vulnerable parts of the brake system and inspection should be complete. A light and mirror will be helpful for a
thorough check. If a hose exhibits any of the above conditions, replace
it with a new one.
Replacement
Front brake hose
Refer to illustration 10.2
2 Disconnect the brake line from the hose fitting, being careful not
t o bend the frame bracket or brake line (see illustration). Use a flare
nut wrench, if available.
3 Unbolt the hose from the frame using a Torx drive socket.
4 Remove the inlet fitting bolt from the brake caliper (see illustration 4.4, if necessary) and separate the hose from the caliper. Discard
the sealing washers.
5 To install the hose, first attach it to the caliper, using new sealing
washers on both sides of the fitting. Tighten the inlet fitting bolt t o
the specified torque.
6 Without twisting the hose, connect the brake line t o the hose fitting, but don't tighten it yet.
7 Install the bolt retaining the hose to the frame, tightening it
securely.
8 Tighten the brake line fitting securely.
10.2 To remove the brake hose, unscrew the brake line from
the hose fitting, using a flare-nut wrench; then unbolt the hose
from the frame, using a Torx socket or screwdriver
The Motor Manual Guy
Chapter 9
Brakes
LINES TO
WHEEL BRAKE
(BLEED
11.8 When bleeding the
brakes, a hose is connected
to the bleeder valve at the
caliper or wheel cylinder
and then submerged in
brake fluid. Air will be seen
as bubbles in the tube and
container. All air must be
expelled before moving to
the next wheel.
FLUID
CONTAINER
PARTIALLY
FILLED WITH
FLUID
9 When the brake hose installation iscomplete, thereshould be no
kinks i n the hose. Make sure the hose doesn't contact any part of the
suspension. Check this by turning the wheels to the extreme left and
right positions. If the hose makes contact, remove it and correct the
installation as necessary. Bleed the system (Section 11).
Rear brake hose
10 Using a back-up wrench, disconnect the hose at the frame bracket, being careful not to bend the bracket or steel lines.
11 Remove the U-clip with a pair of pliers and separate the female
fitting from the bracket.
12 Disconnectthetwo hydraulic lines at the junction block, then unbolt and remove the hose.
13 Bolt the junction block to the axle housing and connectthe lines,
tightening them securely. Without twisting the hose, install the female end of the hose in the frame bracket.
14 Install the U-clip retaining the female end to the bracket.
15 Using a back-up wrench, attach the steel line fittings to the female fittings. Again, be careful not to bend the bracket or steel line.
16 Make sure the hose installation did not loosen the frame bracket.
Tighten the bracket if necessary.
17 Fill the master cylinder reservoir and bleed the system (refer to
Section 11).
Metal brake lines
18 When replacing brake lines besureto usethecorrectparts. Don't
use copper tubing for any brake system components. Purchase steel
brake lines from a dealer or auto parts store.
19 Prefabricated brake line, with the tube ends already flared and
fittings installed, is available at auto parts stores and dealers. These
lines are also bent to the proper shapes.
20 When installing the new line, make sure it's securely supported
in the brackets and has plenty of clearance between moving or hot
components.
21 After installation, check the master cylinder fluid level and add
fluid as necessary. Bleed the brake system as outlined i n the next
Section and test the brakescarefully beforedrivingthevehicle in traffic.
11
Brake system bleeding
Refer to illustrations 11.8 and 11. 15
Warning: Weareyeprotection when bleeding the brakesystem. ff the
fluid comes in contact with your eyes, immediately rinse them with
water and seek medical attention.
Note: Bleeding the hydraulic system is necessary to remove any air
that manages to find its way into the system when it's been opened
during removal and installation of a hose, line, caliper or master cylinder.
Vehicles with conventional (non-ABS) brakes
1 It will probably be necessary to bleed the system at all four
brakes if air has entered the system due to low fluid level, or if the
9-15
11.15 Master cylinderlmodulator bleeding points
brake lines have been disconnected at the master cylinder.
2 If a brake line was disconnected only at a wheel, then only that
caliper or wheel cylinder must be bled.
3 If a brake line is disconnected at a fitting located between the
master cylinder and any of the brakes, that part of the system served
by the disconnected line must be bled.
4 Remove any residual vacuum from the brake power booster by
applying the brake several times with the engine off.
5 Removethe master cylinder reservoir cover and fill the reservoir
with brake fluid. Reinstall the cover. Note: Check the fluidleveloften
during the bleeding operation and add fluid as necessary to prevent
the fluid level from falling low enough to allow air bubbles into the
master cylinder.
6 Have an assistant on hand, as well as a supply of new brake fluid,
a clear container partially filled with clean brake fluid, a length of
3116-inch plastic, rubberorvinyl hosetofit over the bleedervalveand
a wrench t o open and close the bleeder valve.
7 Beginning at the right rear wheel, loosen the bleeder valve
slightly, then tighten itto a pointwhere it is snug but can still be loosened quickly and easily.
8 Place one end of the hose over the bleeder valve and submerge
the other end in brake fluid in the container (see illustration).
9 Have the assistant pump the brakes slowly a few times to get
pressure in the system, then hold the pedal firmly depressed.
10 While the pedal is held depressed, open the bleeder valve just
enough to allow a flow of fluid to leave the valve. Watch for air
bubbles to exit the submerged end of the tube. When the fluid flow
slows after a couple of seconds, close the valve and have your assistant release the pedal.
11 Repeat Steps 9 and 10 until no more air is seen leaving the tube,
then tighten the bleeder valve and proceed t o the left rearwheel, the
right front wheel and the left front wheel, i n that order, and perform
the same procedure. Be sure to check the fluid in the master cylinder
reservoir frequently.
12 Never use old brakefluid. ltcontainsmoisturewhich will deteriorate the brake system components.
13 Refill the master cylinder with fluid at the end of the operation.
14 Check the operation of the brakes. The pedal should feel solid
when depressed, with no sponginess. If necessary, repeat the entire
process. Warning: Do not operate the vehicle if you are in doubt
about the effectiveness of the brake system.
Vehicles with ABS brakes
15 Ifequipped with ABS brakes, begin by bleeding thesystem at the
master cylinder/modulator (see illustration). This is done by loosening and tightening the brake linefittings, one at a time, while an assistant operates the brake pedal. The ignition must be on.
16 The remaining bleeding operations are the same as for conventional brakes. However, note the following:
a) It is imperative that no dirt enter the system with the reservoir
cap off.
b) Insure that the fluid in the master cylinder does not drop too
low during bleeding, since this will lead to severe pump damage.
9
The Motor Manual Guy
Chapter 9
9-16
Start
12.2 Push down on the brake pedal, then
start the engine - the brake pedal should
go down slightly, indicating normal
booster operation
12
Brakes
First
12.3 With the engine turned off,
the pedal should gradually rise
with each pump if the booster
is functioning properly
Power brake booster - check, removal and installation
Refer to illustrations 12.2, 12.3 and 12.9
Operating check
1 Depress the brake pedal several times with the engine off and
make sure that there is no change i n the pedal reserve distance.
2 Depress the pedal and start the engine. If the pedal goes down
slightly, operation is normal (see illustration).
Air tightness check
3 Start the engine and turn it off after one or t w o minutes.
Depress the brake pedal several times slowly. If the pedal goes down
farther the first time but gradually rises after the second or third depression, the booster is air tight (see illustration).
4 Depress the brake pedal while the engine is running, then stop the
engine with the pedal depressed. If there is no change in the pedal
reserve travel after holding the pedal for 3 0 seconds, the booster is
air tight.
Removal
5 Power brake booster units should not be disassembled. They require special tools not normally found in most service stations or shops.
They are fairly complex and because of their critical relationship to brake
performance it is best to replace a defective booster unit with a new
or rebuilt one.
6 To remove the booster, first unbolt the brake master cylinder from
the booster and carefully pull it forward.
7 Disconnect the hose leading from the engine to the booster. Be
careful not to damage the hose when removing it from the booster
fitting.
8 Locate the pushrod connecting the booster to the brake pedal. This
is accessible from the interior in front of the driver's seat.
9 Disconnect the brake light switch wire connector, remove the
pushrod bolt nuts and pull out the bolt (see illustration). Discard the
bolt and nuts and obtain new ones of the same part number for
installation.
1 0 Remove the four nuts holding the brake booster to the firewall.
You may need a light t o see these, as they are up under the dash area
(see illustration 12.9).
1 1 Slide the booster straight out from the firewall until the studs clear
the holes and pull the booster, brackets and gaskets from the engine
compartment area.
12.9 Disconnect the wire connector from
the brake light switch (1 ), then remove the
two booster pushrod nuts (2) and slide out
the pushrod bolt - the booster is fastened
to the firewall by four nuts; three of which
are visible in this photo (3)
1 3 Parking brake - adjustment
Refer to illustration 13.4
1 The adjustment of the parking brake, often overlooked or put off
by many motorists, is actually a fairly critical adjustment. If the parking
brake cables are too slack, the brake won't hold the vehicle on an incline - if they're too tight, the brakes may drag, causing them to wear
prematurely. Another detrimental side effect of a tightly adjusted parking brake cable is the restriction of the automatic adjuster assembly
on the rear drum brakes, which will not allow them to function properly.
2 The first step in adjusting slack parking brake cables is to ensure
the correct adjustment of the rear drum brakes. This can be accomplished by making a series of forward and reverse stops (approximately
1 0 of them), which will bring the brake shoes into proper relationship
with the brake drums.
3 Fully apply and release the parking brake four or five times, then
set the parking brake lever or pedal to the fifth notch.
4 Raise the rear of the vehicle and support it securely on jackstands.
While holding the equalizer rod with a pair of locking pliers, turn the
equalizer locknut (see illustration) until the cables are fairly taut.
5 Release the parking brake and apply it, making sure it travels five
to seven clicks. If it travels too far, tighten the equalizer locknut a little
more. If the travel is less than five clicks, the locknut will have to be
loosened.
6 After the parking brake has been properly adjusted, place the handle
or pedal in the released position and rotate the rear wheels, making
sure the brakes don't drag.
7 Lower the vehicle and test the operation of the parking brake on
an incline.
EQUALIZER
LOCKNUT
EQUALIZER
Installation
Warning: When installing the booster pushrod to brake pedal bolt,
insert i t from the right side o n manual transrnission models a n d from
the left side o n automatic transmission models. In either case, the
bolt must firstpass throught the brake pedal, THEN the push rod (see
illustration 15.3 if necessary).
12 Installation procedures are basically the reverse of those for removal. Tighten the push rod nuts, booster mounting nuts and the
master cylinder mounting nuts to the specified torque.
EQUAI IZER
13.4 To adjust the parking brake, turn the equalizer locknut until
the desired tension on the cables is reached; it may be necessary
t o hold the equalizer rod with a pair of locking pliers to prevent it
from turning
The Motor Manual Guy
Chapter 9
14.3 To disconnect the cable end from the parking brake
lever, pull back on the return spring and maneuver the
cable out of the slot i n the lever
,,
.Al'
(f8'
CABLE\
CLIP
~
PARKING BRAKE
LEVER AND
OPERATING ROD
9-17
Brakes
14.4
Compress the retainer tangs (arrows) t o free the
cable and housing from the backing plate
/
EQUAL/- J(
\
\
AcABLES
r--_
I
L_ .
~ fJiiFirYIA
l..,., / "
4,)~
:
L____________ J
SLEEVE
-
CABLE
SPRING
14.5
t
EQUALIZER
NUTS AND
WASHER
~
SPACER
BRAKELIGHT SWITCH
@
SLEEVE
@~
t
BUSHINGS
SPACER
Parking brake cable installation details (Cherokee
model shown, Comanche similar)
PUSH ROD
BOLT
INSTALL
BOLT THIS
SIDE ON
MAN. TRANS.
MODELS
PAD
1 4 Parking brake cables - replacement
Refer to illustrations 14.3, 14.4 and 14.5
1 Release the parking brake. Loosen the rear wheel lug nuts, raise
the rear of the vehicle and support it securely on jackstands.
2 Remove the rear wheel and brake drum. Loosen the equalizer nut
fully (see illustration 13.4).
3 Following the procedure in Section 6, remove the brake shoes, then
disconnect the parking brake cable end from the parking brake lever
(see illustration).
4 Compress the cable housing retainer tangs at the brake backing
plate (see illustration) and push the cable and housing through the backing plate.
5 Remove the spring and clip from the cable housing (see illustration)
and pry the housing out of the frame bracket, then disconnect the forward end of the cable from the slot in the equalizer (see illustration
13.4)
6 Installation is the reverse of the removal procedure. Be sure to adjust the parking brake as described in Section 13.
15
Brake pedal
-
removal and installation
Refer to illustration 15.3
Removal
1 Disconnect the cable from the negative battery terminal.
2 Disconnect the power brake booster pushrod from the brake pedal
(see Section 1 2).
3 Remove the nut from the right end of the pivot pin and slide the
BUSHINGS
--- ~
/
LOCKNUTS
~,..>
~
;;?'"
/
PUSH ROD
BOLT
CAUTION:
INSTALL BOLT
THIS SIDE
O N AUTO.
TRANS.
11MODELS
1
1.:.- - - -
SPACER
BRAKELIGHT SWITCH
@~
t
SLEEVE
@fii>r-.,
-uyl,../J
t
BUSHINGS
SPACER
I
V"
LOCKNUTS
\
))
(JJ ~
)\BRAKE
~
PEDAL
l__j
15.3 Brake pedal and brake light switch mounting details
(1990 and earlier models)
pin t o the left just far enough t o allow removal of the brake pedal (see
illustration).
4 Check the bushings in the top of the pedal for excessive wear,
replacing them if necessary.
Installation
5 Apply a light coat of multi-purpose grease to the sleeve and
bushings and push them into the top of the pedal.
9
The Motor Manual Guy
Chapter 9 Brakes
9-18
6 Position the pedal in the bracket and slide the pivot pin to the
right, making sure it passes through the pedal bushings, Install the nut
and tighten it to the specified torque.
7 Connect the booster pushrod to the brake pedal, inserting a new
bolt from the right side on models with a manual transmission and
from the left side on automatic transmission models (see illustration
15.3). Install new nuts and tighten them to the specified torques.
8 Connect the negative battery cable and test the brakes for proper
operation.
16
Height sensing proportioning valve general information
Note: Only the Comanche models are equipped with this valve.
The height sensing proportioning valve regulates hydraulic pressure to the rear brakes in accordance with the amount of weight present in the bed of the truck. When the bed is empty, pressure to the
rear brakes will be decreased to avoid locking up the wheels. When
the bed contains a load, the valve senses the lower ride height and allows more hydraulic pressure to the rear brakes.
Due to the special tools, test equipment and skills required to diagnose and service the height sensing proportioning valve, it is not
recommended that the home mechanic attempt the procedures. If servicing the system becomes necessary, take the vehicle to a dealer service department or other qualified repair shop.
Warning: Any suspension modifications that alter the distance between the rear axle and the frame (such as the installation of air shocks,
heavy duty springs or lift kits) will furnish the height sensingproportioning valve with a false reading. This could lead to inadequate braking
characteristics, possibly resulting in an accident.
17
-
Brake light switch replacement
Refer to illustration 17.2
Disconnect the negative battery cable.
2 From under the dash, unplug the brake light switch electrical connector and remove the pushrod bolt (pre-1991 models) or the retaining
clip (1991 and later models). Remove the brake light switch, noting the
positions of the bushings, spacers and sleeves (see accompanying illustration and illustration 15.3).
3 Lubricate the switch bushings, spacers and sleeves with a light
coat of multi-purpose grease and position the switch against the brake
pedal, Install the pushrod bolt and nuts or retaining clip. On pre-1991
models, be sure to tighten the nuts to the torque listed in this Chapter's Specifications.
4 Plug in the electrical connector and reconnect the battery.
DASH
PANEL
SUPPORT
SWITCH
BRAKE PEDAL
(MAN. TRANS.)
·.~~
BOOSTER~
PUSH
ROD
RETAINING
CLIP
•
\
BRAKE PEDAL
(AUTO. TRANS.)
I
BRAKE PEDAL
j,'
17.2 Brake pedal and brake light switch mounting details
5 On pre-1991 models, the switch is not adjustable. On 1991 and
later models, it is adjustable.
6 To check the switch adjustment on 1991 and later models, move
the brake pedal forward by hand and watch the switch plunger. It
should be fully extended at the point at which pedal freeplay is taken
up and brake application begins. A clearance of about 1/8-inch should
exist between the plunger and the pedal at this point.
7 If the plunger-to-pedal clearance is correct and the brake lights are
operating, no adjustment is necessary. If the plunger doesn't fully extend and the clearance between the pedal and switch barrel is insufficient, adjust the switch.
8 To adjust the switch, grasp the brake pedal and pull it to the rear
as far as possible. The switch plunger barrel will "ratchet" to the rear in
its retaining clip to the correct position. Measure the plunger-to-pedal
clearance to make sure it's correct and verify that the brake lights are
still operating correctly. Warning: Make SURE the brake pedal returns
to its fully releasedposition after adjustment. The switch can interfere
with full pedal return if it's too far forward, resulting in dragging brakes
caused by partial brake application.
The Motor Manual Guy
Chapter 10
Suspension and steering systems
Contents
11
removal and installation
Rear leaf spring
12
check and replacement
Rear leaf spring bushing
Rear shock absorber
removal and installation
9
Rear stabilizer bar
removal and installation
10
Steering gear
removal and installation
15
Steering knuckle
removal and installation
7
Steering linkage
inspection, removal and installation . . . . . 16
Steering wheel
removal and installation
13
Suspension and steering check
See Chapter 1
See Chapter 1
Tire pressure check . . . . . . . . . . . . . . . . . . . . . .
Tire rotation . . . . . . . . . . . . . . . . . . . . . . . . . . .
See Chapter 1
Track bar
removal and installation
4
general information
19
Wheels and tires
Balljoints
replacement
8
Front axle suspension arms
removal and installation
5
6
Front coil spring(s) - removal and installation
Front end alignment
general information
20
Front shock absorber
removal and installation
3
Front stabilizer bar and bushings.removal and
2
installation
Front wheel bearing service (4WD vehicles)
See Chapter 8
See Chapter 1
Front wheel bearing service (2WD vehicles)
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
Intermediate shaft
removal and installation
14
See Chapter 1
Power steering fluid level check
removal and installation
17
Power steering pump
bleeding
18
Power steering system
Specifications
Torque Specifications
Ft-lbs
Front Suspension
Track bar ballstud nut
Track bar-to-axle bracket nut . . . . . . . . . . . . . . . . . . . . . . . .
Front axle suspension arm bolts and nuts
Upper arm
Axle end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frame end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lower arm (both ends)
Steering knuckle-to-axle housing balljoint
stud nuts
Brake caliper anchor plate bolts . . . . . . . . . . . . . . . . . . . . . .
62
74
55
66
133
75
77
Rear suspension
Leaf spring
Front and rear mounting bolts
Tie plate U-bolt nuts
Cherokee
Comanche . . . . . . . . . . . . .
......................
109
......................
52
82
Steering
Steering wheel-to-steering shaft hub nut
Intermediate shaft pinch bolts
Steering gear mounting bolts
Pitman arm nut
Center link-to-Pitman arm nut
Center link-to-steering knuckle nut
Tie-rod-to-center link nut
Tie-rod-to-steering knuckle nut
Steering damper-to-center link nut
Steering damper-to-axle bracket bolt
Wheel lug nuts . . . . . . . . . . . . . . . . . . . .
........
25
33
65
185
35
35
35
35
35
55
See Chapter I
10,
....
0
I
I\)
The Motor Manual Guy
1. 1
1
2
3
4
5
6
Front suspension and steering components
Stabilizer bar
Upper suspension arms
Center link
Track bar
Pitman arm
Shock absorber (barely
visible in this photo}
7 Coil spring
8
9
10
11
12
Tie rod
Steering knuckle
Lower suspension arms
Front axle housing
Steering damper
The Motor Manual Guy
1.2
Rear suspension components
1 Stabilizer bar
2 U-bolt
3 Shock absorber
4 Leaf spring
5 Leaf spring shackle
6 Rear axle housing
....
0
I
(,.)
....
Q
The Motor Manual Guy
10-4
1
Chapter 10
Suspension and steering systems
General information
Refer to illustrations I.I and 1.2
All of the vehicles covered by this manual utilize a solid front axle,
suspended by t w o coil springs. Four control arms allow the axle to
move vertically, and lateral movement is prevented by a track bar. A
telescopic dual-action shock absorber is mounted on each side. The
steering knuckles pivot on balljoints and a stabilizer bar controls body
roll (see illustration).
The rear axle on all models is suspended by t w o semi-elliptic leaf
springs and t w o dual-action telescopic shock absorbers (see illustration). A stabilizer bar is installed on most models. As an option, some
Commanche models are equipped with an automatic load leveling
system.
Steering is either manual or power assisted. A recirculating ball type
steering gearbox transmits the turning force through the steering
linkage to the steering knuckle arms. A steering damper is mounted
between the frame and the center link to reduce unwanted bump steer.
An intermediate shaft connects the steering gear to the steering column. The steering column is designed to collapse in the event of an
accident.
Frequently, when working on the suspension or steering system components, you may come across fasteners which seem impossible to
loosen. These fasteners on the underside of the vehicle are continually
subjected to water, road grime, mud, etc., and can become rusted or
"frozen," making them extremely difficult to remove. In order to
unscrew these stubborn fasteners without damaging them (or other
components), be sure t o use lots of penetrating oil and allow it to soak
in for a while. Using a wire brush to clean exposed threads will also
ease removal of the nut or bolt and prevent damage t o the threads.
Sometimes a sharp blow with a hammer and punch is effective in breaking the bond between a nut and bolt threads, but care must be taken
to prevent the punch from slipping off the fastener and ruining the
threads. Heating the stuck fastener and surrounding area with a torch
sometimes helps too, but isn't recommended because of the obvious
dangers associated with fire. Long breaker bars and extension, or
"cheater," pipes will increase leverage, but never use an extension
pipe on a ratchet - the ratcheting mechanism could be damaged.
Sometimes, turning the nut or bolt in the tightening (clockwise) direction first will help to break it loose. Fasteners that require drastic
measures to unscrew should always be replaced with new ones.
Since most of the procedures that are dealt with in this chapter involve jacking up the vehicle and working underneath it, a good pair
of jackstands will be needed. A hydraulic floor jack is the preferred
type of jack to lift the vehicle, and it can also be used t o support certain components during various operation. Warning: Never, under any
circumstances, rely on a jack to support the vehicle while working on
2.2 Note the positions of the bushings and washers before
removing the stabilizer bar-to-link nuts - if the link turns while
loosening the nut, hold it with a pair of locking pliers
it. Whenever any of the suspension or steering fasteners are loosened
or removed they must be inspected and, if necessary, be replaced with
new ones of the same part number or of original equipment quality
and design. Torque specifications must be followed for proper reassembly and component retention. Never attempt to heat or straighten
any suspension or steering components. Instead, replace any bent or
damaged part with a new one.
2
Front stabilizer bar and bushings
removal and installation
Refer to illustrations 2.2 and 2.3
Removal
1 Apply the parking brake. Raise the front of the vehicle and support
it securely on jackstands.
2 Remove the stabilizer bar-to-link nuts, noting how the spacers,
washers and bushings are positioned (see illustration). If it is necessary
to remove the links, simply unbolt them from the axle brackets.
3 Remove the stabilizer bar bracket bolts and detach the bar from
the vehicle (see illustration).
4 Pull the brackets off the stabilizer bar and inspect the bushings
for cracks, hardness and other signs of deterioration. If the bushings
are damaged, replace them.
lnstalla tion
5
Position the stabilizer bar bushings on the bar.
Push the brackets over the bushings and raise the bar up t o the
frame. Install the bracket bolts but don't tighten them completely at
this time.
7 Install the stabilizer bar-to-link nuts, washers, spacers and rubber
bushings and tighten the nuts securely.
8 Tighten the bracket bolts.
6
3
Front shock absorber
-
removal and installation
Refer to illustrations 3.2 and 3.3
Removal
1 Loosen the wheel lug nuts, raise the vehicle and support it securely
on jackstands. Apply the parking brake. Remove the wheel.
2 Remove the upper shock absorber stem nut (see illustration). Use
an open end wrench to keep the stem from turning. If the nut won't
loosen because of rust, squirt some penetrating oil on the stem threads
and allow it to soak in for awhile. It may be necessary to keep the stem
2.3 The stabilizer bar is attached to the frame with t w o
brackets like this - remove the bolts (arrows) t o detach
the bar from the frame - the rubber bushings should be
replaced if they are hard, cracked or otherwise deformed
The Motor Manual Guy
Chapter 10
Suspension and steering systems
10-5
3.2 When removing the shock absorber stem nut (arrow),
it may be necessary to hold the stem with an open end
wrench or locking pliers to prevent it from turning - the
brake master cylinder has been removed for clarity
3.3 The lower end of the shock absorber is connected to
from turning with a pair of locking pliers, since the flats provided for
a wrench are quite small.
3 Remove the t w o lower shock mount nuts and bolts (see illustration)
and pull the shock absorber out from the wheel well. Remove the
washers and the rubber grommets from the top of the shock absorber.
1 Raise the front of the vehicle and support it securely on jackstands.
2 Remove the cotter pin and retaining nut from the ballstud at the
frame rail bracket (see illustration). Discard the cotter pin.
3 Remove the bolt and nut from the axle bracket end of the bar and
remove the bar from the vehicle.
4 Installation is the reverse of the removal procedure, but be sure
to tighten the fasteners t o the specified torque.
Installation
4 Extend the new shock absorber as far as possible. Position a new
washer and rubber grommet on the stem and guide the shock up into
the upper mount.
5 lnstall the upper rubber grommet and washer and wiggle the stem
back-and-forth to ensure the grommets are centered in the mount.
Tighten the stem nut securely.
6 Install the lower mounting bolts and nuts and tighten them securely.
4
Track bar - removal and installation
Refer to illustration 4.2
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design. Torque specifications must be followed for proper reassembly and component retention.
the front axle housing by two bolts and nuts
5 Front axle suspension arms - removal and installation
Refer to illustration 5.2
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design. Torque specifications must be followed for proper
reassembly and component retention.
Note: Remove and install only one suspension arm at a time to avoid
the possibility of the axle housing shifting out of position, which would
make reassembly much more difficult. If it is absolutely necessary to
remove more than one at a time, support the axle with a floor jack.
1 Raise the front of the vehicle and support it securely on jackstands.
2 Remove the nut and bolt securing the suspension arm to the axle
housing (see illustration).
RETAINING
NUT
BRACKET
."
4.2
Track bar mounting details
--~
5.2 Remove the nut (arrow), then slide out the bolt that
secures the suspension arm to the front axle housing
The Motor Manual Guy
Chapter 10
10-6
Suspension and steering systems
3 Remove the arm-to-frame bracket bolt and remove the arm from
the vehicle.
4 Check the arm for distortion and cracks, replacing i t if either of
these conditions are noted.
5 Inspect the bushing in the axle housing (upper arm only) for cracking, hardness and general deterioration. If it is in need of replacement,
reinstall the suspension arm and take the vehicle to a dealer service
department or other qualified shop to have it replaced, as special tools
are required to perform the job successfully.
6 Installation is the reverse of the removal procedure, but be sure
to tighten the fasteners to the specified torque.
6
Front coil spring(s) - removal and installation
Installation
9 Position the coil spring on the axle housing, place the spring retainer over the bottom coil of the spring and tighten the spring retainer
bolt securely.
1 0 Raise the axle up into position and connect the lower suspension
arms to the axle housing (see Section 5). Tighten the fasteners to the
specified torque.
11 Connect the center link to the Pitrnan arm (see Section 15).
12 Connect the track bar to its bracket on the axle (see Section 4).
13 Connect the stabilizer bar links and the shock absorbers to the front
axle housing (see Sections 2 and 3).
1 4 Connect the front driveshaft to the differential pinion shaft yoke
(see Chapter 8 ) .
1 5 Install the wheels and lug nuts and lower the vehicle. Tighten the
lug nuts to the torque specified in Chapter 1.
Refer to illustration 6.7
Removal
1 Loosen the front wheel lug nuts, raise the front of the vehicle and
support it securely on jackstands. Remove the wheels.
2 Referring to Chapter 8 , mark and disconnect the front driveshaft
from the front differential pinion shaft yoke. Hang the driveshaft out
of the way with a piece of wire.
3 Support the axle assembly with a floor jack (under the differential),
or preferably t w o jacks (one at each end of the axle), to provide better
balance. Unbolt the lower suspension arms from the axle (see Section 5).
4 Unbolt the stabilizer bar links and the shock absorbers at the front
axle housing (see Sections 2 and 3).
5 Disconnect the track bar at the axle bracket (see Section 4).
6 Separate the steering center link from the Pitman arm (see Section 15).
7 Slowly lower the axle assembly until the coil springs are fully extended. If you are using only one jack, have an assistant support the
right side of the axle as it's lowered. Remove the spring retainer (see
illustration) and remove the spring from the vehicle.
8 Check the spring for deep nicks and corrosion, which will cause
premature failure of the spring. Replace the spring if these or any other
questionable conditions are evident.
SHOCK
/
ABSORBER/ I
7
Steering knuckle
- removal and installation
Refer to illustrations 7.5, 7.6 and 7.9
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of originalequipment quality
and design. Torque specifications must be followed for proper
reassembly and component retention.
Note: This procedure applies to 4 WD and 2 WD models. If you are working on a 2 WD model, simply ignore references to the components particular to 4 WD vehicles.
Removal
1 Loosenthe wheel lug nuts, raisethevehicleand support it securely on
jackstands. Remove the wheel.
2 Disconnect the tie-rod from the steering knuckle (see Section 16).
3 Remove the disc brake caliper and disc (see Chapter 9).
4 Remove the front axle hub and bearing assembly (4WD only) and remove the axleshaft (see Chapter 8).
5 Remove the cotter pins and loosen the castellated nuts on the balljoint studs (see illustration).
6 Using a large hammer, tap the steering knuckle at the top to separate
it from the balljoint studs (see illustration).
7 Carefully check the steering knuckle for cracks, especially around the
steering arm and spindle mounting area. Check for elongated balljoint
stud holes. Replace the steering knuckle if any of these conditions are
found.
SPRING
RETAINER
-
6.7 Coil spring mounting details
once the spring is fully
extended, unscrew the bolt and remove the spring retainer
(inset), then guide the spring out from between the axle
and frame
7.5 Remove the cotter pins and loosen the castellated
nuts on the upper (A) and lower (not visible i n this photo)
balljoint stud nuts - if a new steering knuckle is being
installed, first remove the anchor plate bolts (Bl, then
remove the anchor plate
The Motor Manual Guy
Chapter 10
Suspension and steering systems
7.6 Strike the steering knuckle at the top to separate it
from the balljoint studs - note that the castellated nuts
are loosened, but not removed - this will prevent the
knuckle from falling when it suddenly breaks loose
10-7
7.9 The split ring seat must be screwed in t o a depth of
0.206 i n (5.23mm), measured from the spindle boss t o
the flats of the seat; this can be measured with a depth
micrometer or a vernier caliper, as shown here
Installation
8 If the steering knuckle is being replaced, unscrew the split ring seat
from the lower mount and transfer it to the new knuckle. Also remove the
disc anchor plate from the old knuckle(see illustration 7.5).
9 Check the depth of the split ring seat in the knuckle using a depth micrometer or vernier caliper ( see illustration). Screwthesplit ring seat in or
out to attain the proper depth of 0.206 in (5.23 mm).
10 Position the steering knuckle on the axle housing, inserting the balljoint studs into the holes in the knuckle. lnstall the nuts and tighten them to
the specified torque. Remember to use new cotter pins.
11 Install the axleshaft (see Chapter 8).
12 Install the front axle hub and bearing assembly (see Chapter 8).
13 Install the disc anchor plate (if removed previously) and tighten the
bolts to the specified torque. Then install the brake disc and caliper (see
Chapter 9).
14 Connect the tie-rod to the steering knuckle (see Sectionm 16)
15 Install the wheel and lug nuts. Lower the vehicle and tighten the lug
nuts to the torque specified in Chapter 1.
8
Balljoints - replacement
The balljoints are a press fit in the front axle housing, which necessitates the use of a special tool to remove and install them. Since the
tool is not normally available to the home mechanic, it is recommended
that the vehicle be taken to a dealer service department or other
qualified repair shop to have the balljoints replaced.
9.3 The lower end of the rear shock absorber mounts t o a stud
on the axle housing and is retained by a nut and washer
9 Rear shock absorber - removal and installation
Refer to illustrations 9.3 and 9.4
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design.
1 Raise the rear of the vehicle and support it securely on jackstands.
2 Support the rear axle assembly with a floor jack placed under the
differential. Raise the jack just enough to take the spring pressure off
the shock absorbers (the shock absorbers limit downward travel of the
suspension).
3 Remove the shock absorber lower retaining nut and washer (see
illustration).
4 Remove the t w o upper mounting bolts (see illustration) and slide
the shock off the lower mounting stud.
5 Installation is the reverse of the removal procedure.
10
9.4 The upper end of the rear shock absorber is mounted
t o the frame with t w o bolts
The Motor Manual Guy
Chapter 10
10-8
10.2
10
Suspension and steering systems
Remove the nut and bolt (arrow) that retain the
stabilizer bar link to the spring tie plate
Rear stabilizer bar
10.3
The stabilizer bar is connected to the frame rails
with two brackets like this
- removal and installation
Refer to illustrations 10.2 and 10.3
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design.
Removal
1
2
Raise the rear of the vehicle and support it securely on jackstands.
Unbolt the stabilizer bar link at the spring tie plate (see illustration).
3 Unbolt the stabilizer bar brackets from the frame rails (see illustration) and remove the bar from the vehicle.
4 Pull the brackets and bushings off the bar and inspect them for
wear, cracking and general deterioration, replacing them if necessary.
Installation
5 Push the bushings and brackets onto the stabilizer bar. Position
the bar against the frame and install the bracket bolts, tightening them
securely.
6 Connect the links to the spring tie plates and tighten them securely.
Lower the vehicle,
11
Rear leaf spring
11.5 The rear axle must be supported before removing
the U-bolt nuts (arrows); otherwise the axle will fall
removal and installation
Refer to illustrations 11.5, 1 1.6 and 11. 7
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design. Torque specifications must be followed for proper reassembly and component retention.
Removal
1 Loosen the rear wheel lug nuts, raise the rear of the vehicle and
support it securely on jackstands. Remove the wheel.
2 Support the rear axle assembly with a floor jack positioned
underneath the differential. Raise the axle just enough to take the spring
pressure off of the shock absorbers.
3 Disconnect the shock absorber from the axle bracket (see Section 9).
4 Unbolt the stabilizer bar links from the spring tie plate (see Section 10).
5 Support the axle, then unscrew the U-bolt nuts (see illustration).
Remove the spring tie plate.
6 Remove the rear spring-to-shackle bolt (see illustration).
7 , Remove the spring front eye-to-frame bracket bolt (see illustration)
and remove the spring from the vehicle.
11.6
Unscrew the nut (arrow), then remove the rear
spring-to-shackle bolt
The Motor Manual Guy
Chapter 10
Suspension and steering systems
10-9
PIPE
SPRING
EYE
Remove the spring front eye-to-frame bracket bolt (arrow)
Installation
8 Installation is the reverse of the removal procedure. Be sure to
tighten the spring mounting bolts and the spring tie plate U-bolt nuts
to the specified torque. Note: The vehicle must be standing at normal
ride height before tightening the front and rear mounting bolts.
12 Rear leaf spring bushing
- check and replacement
Refer to illustration 12.8
Check
1 All models are equipped with slient block type rubber bushings
which are pressed into the spring eyes. The bushings should be inspected for cracks, damage and looseness indicating excessive wear.
To check for wear, jack up the frame until the weight is removed from
the spring bushing. Pry the spring eye up-and-down to check for movement. If there is considerable movement, the bushing is worn and
should be replaced.
Replacement
2
Remove the spring (see Section 1 1 ).
3 The bushings are of t w o different sizes and tools can be fabricated
from threaded rod for pressing them out. For small diameter bushings,
cut an eight inch length of 318-inch diameter threaded rod and, for the
large diameter bushings, cut an eleven-inch length of 112-inch diameter
threaded rod.
4 Insert the threaded rod through the bushing.
5 Place a socket over one end of the rod with the open end toward
the bushing to serve as a driver. The socket must be large enough to
bear against the bushing outer sleeve and small enough to pass throught
the spring eye.
6 Install a flat washer and hex nut on the rod behind the socket.
7 On the opposite end of the threaded rod, install a piece of pipe
t o serve as a receiver. The inside diameter of the pipe must be large
enough to accommodate the bushing while still seating against the
spring eye surface, It must also be long enough to accept the entire
bushing.
8 Secure the pipe section on the rod with a flat washer and nut (see
illustration). The washer must be large enough to properly support the
pipe.
9 Tighten the nuts finger tight t o align the components. The socket
must be positioned in the spring eye and aligned with the bushing and
the pipe must butt against the eye surface so the bushing can pass
through it.
1 0 Press the bushing out of the spring eye by tightening the nut at
the socket end of the rod,
11 Remove the bushing and tool from the spring eye.
12 Install the new bushing on the threaded rod and assemble and align
the tools as previously described.
FLAT
THREADED
WASHER
ROD
12.8 A threaded rod and t w o appropriately-sized sockets
can be used t o remove and install the spring eye bushings
13 Line up the bushing with the spring eye and press the new bushing
into position.
1 4 Loosen the nuts and check t o make sure the bushing is centered
in the spring eye with the ends of the bushing flush with or slightly
below the sides of the eye. If necessary, reinstall the tools and adjust
the bushing position.
13 Steering wheel
- removal and installation
Refer to illustrations 3.2, 13.3 and 13.4
1 Disconnect the cable from the negative terminal of the battery.
2 Detach the horn pad from the steering wheel and disconnect the
wires t o the horn switch (see illustration).
13.2 After removing the horn pad, disconnect the horn switch
wires; the horn pad is retained t o the steering wheel by thre1:1
screws, accessible from the dashboard side of the wheel
..
The Motor Manual Guy
Chapter 10
10-10
Suspension and steering systems
13.4
13.3 Before removing the steering wheel, check to see if
any relationship marks exist (arrows) - if not, use a sharp
scribe or white paint to make your own marks
Remove the wheel from the shaft with a puller DO NOT HAMMER ON THE SHAFT!
3 Remove the steering wheel retaining nut, then mark the relationship
of the steering shaft to the hub (if marks don't already exist or don't
line up) to simplify installation and ensure steering wheel alignment
(see illustration).
4 Use a puller to detach the steering wheel from the shaft (see illustration). Don't hammer on the shaft to dislodge the steering wheel.
5 To install the wheel, align the mark on the steering wheel hub with
the mark on the shaft and slip the wheel onto the shaft. Install the
nut and tighten it t o the specified torque.
6 Connect the horn wire and install the horn pad.
7 Connect the negative battery cable.
14
14.2 Using white paint. mark the relationship of the upper and
lower universal joints to the steering shaft and steering gear input
shaft, respectively; then remove the upper pinch bolt (arrow) . . .
Intermediate shaft - removal and installation
Refer to illustrations 14.2 and 14.3
Turn the front wheels to the straight ahead position.
1
2 Using white paint, mark the relationship of the upper universal joint
to the steering shaft and the lower universal joint to the steering gear
input shaft (see illustration).
3 Remove the upper and lower universal joint pinch bolts (see illustration). Some designs require the steering gear to be loosened (bolts
removed) and repositioned t o allow shaft removal.
4 Pry the intermediate shaft out of the steering shaft universal joint
with a large screwdriver, then pull the shaft from the steering gearbox.
5 Installation is the reverse of the removal procedure. Be sure to align
the marks and tighten the pinch bolts to the specified torque.
15
Steering gear - removal and installation
Refer to illustrations 15.4, 15.5 and 15.6
Removal
14.3
...
and lower pinch bolt (arrow)
1 Raise the front of the vehi~le and support it securely on jackstands.
Apply the parking brake.
2 Place a drain pan under the steering gear (power steering only).
Remove the hosesllines and cap the ends to prevent excessive fluid
loss and contamination. If available, use a flare-nut wrench to remove
the hosesllines.
3 Mark the relationship of the intermediate shaft lower universal joint
to the steering gear input shaft. Remove the intermediate shaft lower
pinch bolt (see illustration 14.3).
4 Remove the Pitman arm nut and washer. Mark the relationship of
The Motor Manual Guy
Chapter 10
15.4
Suspension and steering systems
Before removing the Pitman arm, mark its
relationship to the steering gear shaft
15.5
10-11
Use a two-jaw puller to separate the Pitman arm
from the steering gear shaft
the Pitman arm t o the shaft so it can be installed in the same position
(see illustration).
5 Separate the Pitman arm from the shaft with a two-jaw puller (see
illustration).
6 Support the steering gear and remove the mounting bolts (see illustration). Lower the unit, separate the intermediate shaft from the
steering gear input shaft and remove the steering gear from the vehicle.
Installation
7 Raise the steering gear into position and connect the intermediate
shaft, aligning the marks.
8 Install the mounting bolts and washers and tighten them t o the
specified torque.
9 Slide the Pitman arm onto the shaft. Make sure the marks are
aligned, Install the washer and nut and tighten the nut t o the specified
torque.
1 0 Install the intermediate shaft lower pinch bolt and tighten i t t o the
specified torque.
11 Connect the power steering hoses/lines t o the steering gear and
fill the power steering pump reservoir with the recommended fluid (see
Chapter 1).
1 2 Lower the vehicle and bleed the steering system as discussed in
Section 18.
16
Steering linkage - inspection. removal and installation
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design. Torque specifications must be followed for proper
reassembly and component retention. Never attempt to heat, straighten
or weld any suspension or steering component. Instead, replace any
bent or damaged part with a new one.
Caution: DO NOT use a "pickle fork" type balljoint separator
it may
damage the balljoint seals.
Inspection
1 The steering linkage connects the steering gear t o the front wheels
and keeps the wheels in proper relation t o each other (see illustration 1.1 ). The linkage consists of the Pitman arm, fastened t o the steering gear shaft, which moves the center link back and forth. The backand-forth motion of the center link is transmitted t o the right steering
knuckle. A tie-rod assembly connects the center link t o the left knuckle.
'The tie-rod is made up of a tube, clamps and t w o tie-rod ends. A steering damper, connected between the center link and the frame reduces
shimmy and unwanted forces t o the steering gear.
15.6
The steering gear is mounted to the frame rail with
three bolts (arrows)
2 Set the wheels in the straight ahead position and lock the steering
wheel.
3 Raise one side of the vehicle until the tire is approximately -inch
o f f the ground.
4 Mount a dial indicator w i t h the needle resting on the outside edge
of the wheel. Grasp the front and rear of the tire and using light pressure, wiggle the wheel back-and-forth and note the dial indicator
reading. The gauge reading should be less than 0.108-inch. If the play
i n the steering system is more than specified, inspect each steering
linkage pivot point and ball stud for looseness and replace parts if
necessary.
5 Raise the vehicle and support i t on jackstands. Check for torn ball
stud boots, frozen joints and bent or damaged linkage components.
Removal and installation
Refer to illustrations 16.8 and 16.9
Tie-rod
6 Loosen the wheel lug nuts, raise the vehicle and support i t securely
on jackstands. Apply the parking brake. Remove the wheel.
7 Remove the cotter pins and loosen, but do not remove, the castellated nuts from the ball studs on each end of the tie-rod.
10···
The Motor Manual Guy
10-12
Chapter 10
Suspension and steering systems
16.8 Use a two-jaw puller t o detach the tie-rod end from
the steering knuckle - notice the nut has been loosened
but not removed; this will prevent the components from
separating violently
8 Using a two-jaw puller, separate the tie-rod ends from the steering
knuckle and the center link (see illustration). Remove the castellated
nuts and pull the tie-rod ends frorr. the knuckle and center link.
9 If the tie-rod ends must be replaced, measure the distance from
the end of the tie-rod tube to the center of the ball stud and record
i t (see illustration). Loosen the adjuster tube clamp and unscrew the
tie-rod end.
10 Lubricate the threaded portion of the tie-rod end with chassis grease.
Screw the new tie-rod end into the adjuster tube and adjust the distance
from the tube to the ball stud to the previously measured dimension.
The number of threads showing on the inner and outer tie-rod ends
should be equal within three threads. Don't tighten the clamp yet.
1 1 To install the tie-rod, insert the tie-rod end ball studs into the steering knuckle and center link until they're seated. Install the nuts and
tighten them to the specified torque. If a ball stud spins when attempting to tighten the nut, force it into the tapered hole with a large pair
of pliers.
12 Install new cotter pins. If necessary, tighten the nut slightly to align
a slot in the nut with the hole in the ball stud.
13 Tighten the clamp nuts. The bolts should be nearly horizontal.
1 4 Install the wheel and lug nuts, lower the vehicle and tighten the
lug nuts to the torque specified in Chapter 1. Drive the vehicle to an
alignment shop to have the front end alignment checked and, if
necessary, adjusted.
16.9 If the tie-rod ends must be replaced, measure the distance
from the end of the tie rod tube t o the center of the ballstud so
the new tie-rod end can be set t o this dimension
17
Power steering pump
removal and installation
Refer to illustration 1 7.2, 1 7.3, 7.4 and 1 7.5
Warning: Whenever any of the suspension or steering fasteners are
loosened or removed they must be inspected and, if necessary, replaced
with new ones of the same part number or of original equipment quality
and design.
1 Loosen the pump drivebelt and slip the belt over the pulley (see
Chapter 1).
2 Using a suction gun, suck out as much power steering fluid from
the reservoir as possible. Position a drain pan under the pump and
disconnect the high pressure line and fluid return hose (see illustration). It may be necessary to remove the air cleaner housing for access
Center link
1 5 Raise the front of the vehicle and support it securely on jackstands.
Apply the parking brake.
16 Loosen, but do not remove, the nuts securing the center link ball
studs to the tie-rod and steering knuckle. Separate the joints with a
two-jaw puller, then remove the nuts (see illustration 16.8).
17 Separate the center link from the Pitrnan arm using the same technique. If the tie-rod end on the left end of the center link is in need
of replacement, follow Steps 9 and 1 0 of this Section.
18 lnstallation is the reverse of the removal procedure. If the ball studs
spin when attempting to tighten the nuts, force them into the tapered
holes with a large pair of pliers. Be sure to tighten all of the nuts to
the specified torque.
Pitman arm
19 Refer to Section 15 of this Chapter for the Pitman arm removal
procedure.
Steering damper
2 0 Raise the front of the vehicle and support it securely on jackstands.
21 Separate the steering damper from the center link using the technique described in Step 16.
22 Unbolt the damper from the frame and remove it from the vehicle.
23 Installation is the reverse of the removal procedure.
FLUID
RETURN
HOSE
17.2
Power steering pump line and hose connections and
rear attaching bolts
The Motor Manual Guy
Chapter 10
Suspensia
17.4
17.3
10-1 3
and steering systems
This special tool, designed for removing power steering
pump pulleys, is available at most auto parts stores
Power steering pump front attaching bolts
to the return hose (if so, see Chapter 4). Cap the ends of the lines to
prevent excessive fluid leakage and the entry of contaminants.
3 Remove the front attaching bolts (see illustration) and the rear attaching bolts (see illustration 17.2) and nuts, then lift the pump from
the engine.
4 If it is necessary to remove the pulley from the pump, first measure
how far the pump shaft protrudes from the face of the pulley hub.
Remove the pulley from the shaft with a special power steering pump
pulley removal tool (see illustration). This tool can be purchased at most
auto parts stores.
5 A special pulley installation tool is available for pressing the pulley
back onto the pump shaft, but an alternate tool can be fabricated from
a long bolt, nut, washer and a socket of the same diameter as the pulley
hub (see illustration). Push the pulley onto the shaft until the the shaft
protrudes from the hub the previously recorded amount.
6 Installation of the power steering pump is the reverse of the removal
procedure. Be sure to bleed the power steering system following the
procedure in Section 18.
18 Power steering system - bleeding
1 Following any operation in which the power steering fluid lines have
been disconnected, the power steering system must be bled to remove
all air and obtain proper steering performance.
2 With the front wheels in the straight ahead position, check the
power steering fluid level and, if low, add fluid until it reaches the Cold
(Cl mark on the dipstick.
3 Start the engine and allow it t o run at fast idle. Recheck the fluid
level and add more if necessary t o reach the Cold (C) mark on the dipstick.
4 Bleed the system by turning the wheels from side-to-side, without
hitting the stops. This will work the air out of the system. Keep the
reservoir full of fluid as this is done.
5 When the air is worked out of the system, return the wheels to
the straight ahead position and leave the vehicle running for several
more minutes before shutting it off.
6 Road test the vehicle to be sure the steering system is functioning
normally and noise free.
7 Recheck the fluid level t o be sure it is up to the Hot (H) mark on
the dipstick while the engine is at normal operating temperature. Add
fluid if necessary (see Chapter 1 ).
19
17.5 A long bolt with the same thread pitch as the
internal threads of the power steering pump shaft. a nut.
washer and a socket that is the same diameter as the
pulley hub can be used to install the pulley on the shaft
r-__
METRIC TIRE SIZES
P 185 / 8 0 R 13
P
T -
C -
TIRE TYPET
PASSENGER
TEMPORARY
T~
ASPECT RATIO
(SECTION HEIGHT)
~IAMETER
(INCHES)
\
10
Wheels and tires - general information
Refer to illustration 19.
All vehicles covered by this manual are equipped with metric-sized
fiberglass or steel belted radial tires (see illustration). Use of other size
13
14
COM~:R-~~:. ····--~:ECT!O;~ WiDTH)
\
SECTION WIDTH
15
75
\
(MILLIMETERS)
CONSTRUCTION TYPE
80
185
R - RADIAL
195
B - BIAS - BELTED
205
D
DIAGONAL (BIASI
ETC
19.1 Metric tire size code
The Motor Manual Guy
Chapter 10
10-14
Suspension and steering systems
.....
VERTICAL-I !-CASTER ANGLE
I
FRONT
OF VEHICLE
20.1
Toe-in is the only normally adjusted
alignment setting
or type o f tires may affect the ride and handling o f the vehicle. Don't
mix different types of tires, such as radials and bias belted, on the same
vehicle as handling may be seriously affected. It's recommended that
tires be replaced in pairs on the same axle, but if only one tire is being
replaced, be sure it's the same size, structure and tread design as the
other.
Because tire pressure has a substantial effect on handling and wear,
the pressure on all tires should be checked at least once a month or
before any extended trips (see Chapter 1 ).
Wheels must be replaced if they are bent, dented, leak air, have
elongated bolt holes, are heavily rusted, out of vertical symmetry or
if the lug nuts won't stay tight. Wheel repairs that use welding or peening are not recommended.
Tire and wheel balance is important t o the overall handling, braking
and performance of the vehicle. Unbalanced wheels can adversely
affect handling and ride characteristics as well as tire life. Whenever
a tire is installed on a wheel, the tire and wheel should be balanced
by a shop with the proper equipment.
20 Front end alignment - general information
Refer to illustrations 20. and 20.2
A front end alignment refers t o the adjustments made t o the front
wheels so they are in proper angular relationship t o the suspension
and the ground. Front wheels that are out of proper alignment not only
affect steering control, but also increase tire wear. The only front end
adjustments possible on these vehicles are caster and toe-in.
Getting the proper front wheel alignment is a very exacting process,
one in which complicated and expensive machines are necessary t o
perform the job properly. Because of this, you should have a technician
with the proper equipment perform these tasks. We will, however, use
this space t o give you a basic idea of what is involved with front end
20.2 Caster (the tilting of the top of the front steering
axis from vertical) affects the self-return characteristics of
the steering system; it is not a routine adjustment, but
should be checked whenever the front axle housing or front
suspension arms are changed
alignment so you can better understand the process and deal intelligently w i t h the shop that does the work.
Toe-in is the turning in of the front wheels (see illustration). The purpose of a toe specification is t o ensure parallel rolling of the front
wheels. In a vehicle w i t h zero toe-in, the distance between the front
edges of the wheels will be the same as the distance between the rear
edges of the wheels. The actual amount o f toe-in is normally only a
fraction of an inch. Toe-in adjustment is controlled by the tie-rod end
position on the tie-rod. Incorrect toe-in will cause the tires t o wear improperly by making them scrub against the road surface.
Caster is the tilting of the top of the front steering axis from the vertical (see illustration). A tilt toward the rear is positive caster and a
tilt toward the front is negative caster. This angle is adjusted by adding
or subtracting shims at the rear of the lower suspension arms.
Camber (the tilting o f the front wheels from vertical when viewed
from the front of the vehicle) is factory present at
and cannot be
adjusted. If the camber angle isn't correct, the components causing
the problem must be replaced. NEVER ATTEMPT TO ADJUST THE
CAMBER ANGLE BY HEATING OR BENDING THE AXLE OR ANY
OTHER SUSPENSION COMPONENT!
The Motor Manual Guy
Chapter 11 Body
Contents
Body - maintenance
Body repair
major damage
Body repair - minor damage
Bumpers
removal and installation
Center console - removal and installation . . . . . . . . . . . . . .
Dashboard panels
removal and installation
Door latch, lock cylinder and handle - removal
and installation
Door - removal, installation and adjustment
Door trim panel
removal and installation . . . . . . . . . . . . . .
Door window glass - removal and installation
Fixed glass
replacement
2
6
5
11
17
16
General information
Hinges and locks - maintenance
Hood
removal, installation and adjustment
Liftgate (Cherokee models)
removal, installation
and adjustment
Outside mirror - removal and installation
Radiator grille
removal and installation
Seats - removal and installation
Tailgate (Comanche models)
removal and installation
Upholstery and carpets - maintenance.
Vinyl trim
maintenance.
19
13
12
18
8
1
7
10
14
20
9
21
15
4
3
Specifications
Torque specifications
Ft-lb
Door
Glass stud nuts.
Hinge bolts
Hood-to-hinge bolts
Liftgate striker screws
Front seat retaining nuts.
Seatback cushion pivot bolts
Rear seat-to-bottom cushion hinge striker bolt
4
26
23
22
18
33
33
1
General information
The vehicles covered in this manual have a separate frame and body.
As with other parts of the vehicle, proper maintenance of body components plays an important part in preserving the vehicle's market
value. It's far less costly to handle small problems before they grow
into larger ones. Information in this Chapter will tell you all you need
to know to keep seals sealing, body panels aligned and general appearance up to par.
Major body components which are particularly vulnerable in accidents
are removable. These include the hood, fenders, grille and doors. It's
often cheaper and less time consuming to replace an entire panel than
it is to attempt a restoration of the old one. However, this must be
decided on a case-by-case basis.
2
Body - maintenance
1 The condition of your vehicle's body is very important, because
the resale value depends a great deal on it. It's much more difficult
to repair a neglected or damaged body than it is to repair mechanical
components. The hidden areas of the body, such as the wheel wells,
the frame and the engine compartment, are equally important, although
they don't require as frequent attention as the rest of the body.
2 Once a year, or every 12,000 miles, it's a good idea to have the
underside of the body steam cleaned. All traces of dirt and oil will be
removed and the area can then be inspected carefully for rust, damaged
brake lines, frayed electrical wires, damaged cables and other problems.
The front suspension components should be greased after completion
of this job.
11
The Motor Manual Guy
Chapter 11
11-2
3 At the same time, clean the engine and the engine compartment
with a steam cleaner or water soluble degreaser.
4 The wheel wells should be given close attention, since undercoating
can peel away and stones and dirt thrown up by the tires can cause
the paint to chip and flake, allowing rust to set in. If rust is found, clean
down to the bare metal and apply an anti-rust paint.
5 The body should be washed about once a week. Wet the vehicle
thoroughly to soften the dirt, then wash it down with a soft sponge
and plenty of clean soapy water. If the surplus dirt is not washed off
very carefully, it can wear down the paint.
6 Spots of tar or asphalt thrown up from the road should be removed
with a cloth soaked in solvent.
7 Once every six months, wax the body and chrome trim. If a chrome
cleaner is used to remove rust from any of the vehicle's plated parts,
remember that the cleaner also removes part of the chrome, so use
it sparingly.
3
Vinyl trim - maintenance
Don't clean vinyl trim with detergents, caustic soap or petroleumbased cleaners. Plain soap and water works just fine, with a soft brush
to clean dirt that may be ingrained. Wash the vinyl as frequently as
the rest of the vehicle.
After cleaning, application of a high quality rubber and vinyl protectant will help prevent oxidation and cracks. The protectant can also
be applied to weatherstripping, vacuum lines and rubber hoses, which
often fail as a result of chemical degradation, and to the tires.
Body
Repair of dents
4 When repairing dents, the first job is to pull the dent out until the
affected area is as close as possible to its original shape. There is no
point in trying to restore the original shape completely as the metal
in the damaged area will have stretched on impact and cannot be restored t o its original contours. It is better to bring the level of the dent
up to a point which is about 118-inch below the level of the surrounding
metal. In cases where the dent is very shallow, it is not worth trying
to pull it out at all.
5 If the back side of the dent is accessible, it can be hammered out
gently from behind using a soft-face hammer. While doing this, hold
a block of wood firmly against the opposite side of the metal to absorb
the hammer blows and prevent the metal from being stretched.
6 If the dent is in a section of the body which has double layers,
or some other factor makes it inaccessible from behind, a different
technique is required. Drill several small holes through the metal inside
the damaged area, particularly in the deeper sections. Screw long, self
tapping screws into the holes just enough for them to get a good grip
in the metal. Now the dent can be pulled out by pulling on the protruding heads of the screws with locking pliers.
7 The next stage of repair is the removal of paint from the damaged
area and from an inch or so of the surrounding metal. This is easily
done with a wire brush or sanding disk in a drill motor, although it can
be done just as effectively by hand with sandpaper. To complete the
preparation for filling, score the surface of the bare metal with a screwdriver or the tang of a file or drill small holes in the affected area. This
will provide a good grip for the filler material. To complete the repair,
see the Section on filling and painting.
Repair of rust holes or gashes
4
Upholstery and carpets - maintenance
1 Every three months remove the carpets or mats and clean the interior of the vehicle (more frequently if necessary). Vacuum the upholstery and carpets to remove loose dirt and dust.
2 Leather upholstery requires special care. Stains should be removed
with warm water and a very mild soap solufion. Use a clean, damp
cloth t o remove the soap, then wipe again with a dry cloth. Never use
alcohol, gasoline, nail polish remover or thinner to clean leather
upholstery.
3 After cleaning, regularly treat leather upholstery with a leather wax.
Never use car wax on leather upholstery.
4 In areas where the interior of the vehicle is subject t o bright
sunlight, cover leather seats with a sheet if the vehicle is to be left
out for any length of time.
--
5 Body repair - minor damage
See photo sequence
Repair of minor scratches
1 If the scratch is superficial and does not penetrate to the metal
of the body, repair is very simple. Lightly rub the scratched area with
a fine rubbing compound to remove loose paint and built up wax. Rinse
the area with clean water.
2 Apply touch-up paint to the scratch, using a small brush. Continue
to apply thin layers of paint until the surface of the paint in the scratch
is level with the surrounding paint. Allow the new paint at least t w o
weeks t o harden, then blend it into the surrounding paint by rubbing
with a very fine rubbing compound. Finally, apply a coat of wax to
the scratch area.
If the scratch has penetrated the paint and exposed the metal of
the body, causing the metal to rust, a different repair technique is required. Remove all loose rust from the bottom of the scratch with a
pocket knife, then apply rust inhibiting paint to prevent the formation
of rust in the future. Using a rubber or nylon applicator, coat the
scratched area with glaze-type filler. If required, the filler can be mixed
with thinner to provide a very thin paste, which is ideal for filling narrow
scratches. Before the glaze filler in the scratch hardens, wrap a piece
of smooth cotton cloth around the tip of a finger. Dip the cloth in thinner
and then quickly wipe it along the surface of the scratch. This will ensure that the surface of the filler is slightly hollow. The scratch can
now be painted over as described earlier in this section.
8 Remove all paint from the affected area and from an inch or so
of the surrounding metal using a sanding disk or wire brush mounted
in a drill motor. If these are not available, a few sheets of sandpaper
will do the job just as effectively.
9 With the paint removed, you will be able to determine the severity
of the corrosion and decide whether to replace the whole panel, if possible, or repair the affected area. New body panels are not as expensive
as most people think and it is often quicker to install a new panel than
to repair large areas of rust.
1 0 Remove all trim pieces from the affected area except those which
will act as a guide to the original shape of the damaged body, such
as headlight shells, etc. Using metal snips or a hacksaw blade, remove
all loose metal and any other metal that is badly affected by rust. Hammer the edges of the hole inward to create a slight depression for the
filler material.
1 1 Wire brush the affected area to remove the powdery rust from the
surface of the metal. If the back of the rusted area is accessible, treat
it with rust inhibiting paint.
12 Before filling is done, block the hole in some way. This can be done
with sheet metal riveted or screwed into place, or by stuffing the hole
with wire mesh.
13 Once the hole is blocked off, the affected area can be filled and
painted. See the following subsection on filling and painting.
Filling and painting
1 4 Many types of body fillers are available, but generally speaking,
body repair kits which contain filler paste and a tube of resin hardener
are best for this type of repair work. A wide, flexible plastic or nylon
applicator will be necessary for imparting a smooth and contoured finish
to the surface of the filler material. Mix up a small amount of filler on
a clean piece of wood or cardboard (use the hardener sparingly). Follow
the manufacturer's instructions on the package, otherwise the filler
will set incorrectly.
1 5 Using the applicator, apply the filler paste t o the prepared area.
Draw the applicator across the surface of the filler to achieve the desired
contour and to level the filler surface. As soon as a contour that approximates the original one is achieved, stop working the paste. If you
continue, the paste will begin t o stick to the applicator. Continue to
add thin layers of paste at 20-minute intervals until the level of the
filler is just above the surrounding metal.
16 Once the filler has hardened, the excess can be removed with a
body file. From then on, progressively finer grades of sandpaper should
be used, starting with a 180-grit paper and finishing with 600-grit wetor-dry paper. Always wrap the sandpaper around a flat rubber or
The Motor Manual Guy
Chapter 11
wooden block, otherwise the surface of the filler will not be completely
flat. During the sanding of the filler surface, the wet-or-dry paper should
be periodically rinsed in water. This will ensure that a very smooth finish
is produced in the final stage.
17 At this point, the repair area should be surrounded by a ring of
bare metal, which in turn should be encircled by the finely feathered
edge of good paint. Rinse the repair area with clean water until all of
the dust produced by the sanding operation is gone.
18 Spray the entire area with a light coat of primer. This will reveal
any imperfections in the surface of the filler. Repair the imperfections
with fresh filler paste or glaze filler and once more smooth the surface
with sandpaper. Repeat this spray-and-repair procedure until you are
satisfied that the surface of the filler and the feathered edge of the
paint are perfect. Rinse the area with clean water and allow it to dry
completely.
19 The repair area is now ready for painting. Spray painting must be
carried out in a warm, dry, windless and dust free atmosphere. These
conditions can be created if you have access to a large indoor work
area, but if you are forced to work in the open, you will have to pick
the day very carefully. If you are working indoors, dousing the floor
in the work area with water will help settle the dust which would otherwise be in the air. If the repair area is confined to one body panel, mask
off the surrounding panels. This will help minimize the effects of a slight
mismatch in paint color. Trim pieces such as chrome strips, door
handles, etc., will also need to be masked off or removed. Use masking
tape and several thicknesses of newspaper for the masking operations.
2 0 Before spraying, shake the paint can thoroughly, then spray a test
area until the spray painting technique is mastered. Cover the repair
area with a thick coat of primer. The thickness should be built up using
several thin layers of primer rather than one thick one. Using 600-grit
wet-or-dry sandpaper, rub down the surface of the primer until it is
very smooth. While doing this, the work area should be thoroughly
rinsed with water and the wet-or-dry sandpaper periodically rinsed as
well. Allow the primer to dry before spraying additional coats.
21 Spray on the top coat, again building up the thickness by using
several thin layers of paint. Begin spraying in the center of the repair
area and then, using a circular motion, work out until the whole repair
area and about t w o inches of the surrounding original paint is covered.
Remove all masking material 10 to 15 minutes after spraying on the
final coat of paint. Allow the new paint at least t w o weeks to harden,
then use a very fine rubbing compound to blend the edges of the new
paint into the existing paint. Finally, apply a coat of wax.
6
Body repair - major damage
1 Major damage must be repaired by an auto body shop specifically
equipped to perform unibody repairs. These shops have the specialized equipment required to do the job properly.
2 If the damage is extensive, the body must be checked for proper
alignment or the vehicle's handling characteristics may be adversely
affected and other components may wear at an accelerated rate.
3 Due to the fact that all of the major body components (hood,
fenders, etc.) are separate and replaceable units, any seriously damaged
components should be replaced rather than repaired. Sometimes the
components can be found in a wrecking yard that specializes in used
vehicle components, often at considerable savings over the cost of
new parts.
7
11-3
Body
SCREWS
9.1
The grille is held in place by eight screws
and techniques. These operations should be left t o a dealer service
department or a shop specializing in glass work.
9
Radiator grille
removal and installation
Refer to illustration 9. 1
1 Remove the phillips head mounting screws and detach the grille
from the vehicle (see illustration).
2 Installation is the reverse of removal.
10 Hood - removal, installation and adjustment
Refer to illustrations 10.2, 10.4 and 10. 12
Note: The hood is heavy and somewhat awkward to remove and install - at least two people should perform this procedure.
Removal and ins talla tion
1 Use blankets or pads to cover the cowl area of the body and the
fenders. This will protect the body and paint as the hood is lifted off.
2 Scribe or paint alignment marks around the bolt heads to insure
proper alignment during installation (see illustration).
3 Disconnect any cables or wire harnesses which will interfere with
removal.
Hinges and locks - maintenance
Once every 3000 miles, or every three months, the hinges and latch
assemblies on the doors, hood and liftgate or tailgate should be given
a few drops of light oil or lock lubricant. The door latch strikers should
also be lubricated with a thin coat of grease to reduce wear and ensure
free movement. Lubricate the door and liftgate locks with spray-on
graphite lubricant.
11
8 Fixed glass - replacement
Replacement of the windshield and fixed glass requires the use of
special fast-setting adhesive/caulk materials and some specialized tools
10.2 Use white paint or a marker t o make alignment
marks around the hood bolt heads - note the padding
used t o protect the body in case the hood swings back
The Motor Manual Guy
These photos illustrate a method of repairing simple dents. They are intended to supplement Body repair
damage in this Chapter and should not be used as the sole instructions for body repair on these vehicles.
- minor
...
1 If you can't access the backside of the body panel to hammer
out the dent, pull it out with a slide-hammer-typedent puller. In
the deepest portion of the dent or along the crease line, drill or
punch hole(s) at least one inch apart.
2
then screw the slide-hammer into the hole and operate it.
Tap with a hammer near the edge of the dent to help 'pop' the
metal back to its original shape. When you're finished, the dent
area should be close to its original contour and about 118-inch
below the surface of the surrounding metal
3 Using coarse-grit sandpaper, remove the paint down to the
bare metal. Hand sanding works fine, but the disc sander shown
here makes the job faster. Use finer (about 320-grit) sandpaper to
feather-edge the paint at least one inch around the dent area
4 When the paint is removed, touch will probably be more
helpful than sight for telling if the metal is straight. Hammer
down the high spots or raise the low spots as necessary.
Clean the repair area with wax/silicone remover
5 Following label instructions, mix up a batch of plastic filler and
hardener. The ratio of filler to hardener is critical, and, if you mix it
incorrectly, it will either not cure properly or cure too quickly (you
won't have time to file and sand it into shape)
6 Working quickly so the filler doesn't harden, use a plastic
applicator to press the body filler firmly into the metal, assuring it
bonds completely. Work the filler until it matches the original
contour and is slightly above the surrounding metal
..
The Motor Manual Guy
7 Let the filler harden until you can just dent it with your
fingernail. Use a body file or Surform tool (shown here) to roughshape the filler
9 You shouldn't be able to feel any ridge at the transition from
the filler to the bare metal or from the bare metal to the old paint,
As soon as the repair is flat and uniform, remove the dust and
mask off the adjacent panels or trim pieces
8 Use coarse-grit sandpaper and a sanding board or block to
work the filler down until it's smooth and even. Work down to
finer grits of sandpaper - always using a board or block ending
up with 360 or 400 grit
-
10 Apply several layers of primer to the area. Don't spray the
primer on too heavy, so it sags or runs, and make sure each coat
is dry before you spray on the next one. A professional-type spray
gun is being used here, but aerosol spray primer is available
inexpensively from auto parts stores
11
11 The primer will help reveal imperfections or scratches. Fill
these with glazing compound. Follow the label instructions and
sand it with 360 or 400-grit sandpaper until it's smooth. Repeat
the glazing, sanding and respraying until the primer reveals a
perfectly smooth surface
12 Finish sand the primer with very fine sandpaper (400 or 600grit) to remove the primer overspray. Clean the area with water
and allow it to dry. Use a tack rag to remove any dust, then apply
the finish coat. Don't attempt to rub out or wax the repair area
until the paint has dried completely (at least two weeks)
The Motor Manual Guy
Chapter 11 Body
11-6
4 Have an assistant support the weight of the hood. Remove the
hinge-to-hood bolts and adjusting shims (see illustration).
5 Lift off the hood.
6 Installation is the reverse of removal. Be sure to reinstall the adjusting shims and tighten the hinge-to-hood bolts t o the specified
torque.
Adjustment
10.4 Be sure t o remove and keep track of the adjusting shims
before lifting the hood off - it's a good idea t o mark them so
you know which side t o return them to on installation
7 Fore-and-aft and side-to-side adjustment of the hood is done by
moving the hood in relation to the hinge plate after loosening the bolts.
8 Scribe or paint around the hood bolt heads so you can judge the
amount of movement (see illustration 10.2).
9 Loosen the bolts and move the hood into correct alignment. Move
it only a little at a time. Tighten the hood bolts and carefully lower the
hood t o check the alignment.
10 If necessary after installation, the entire hood latch assembly can
be adjusted up-and-down as well as from side-to-side on the radiator
support so the hood closes securely and the front of the hood is flush
with the fenders. To do this, scribe a line around the hood latch mounting bolts to provide a reference point. Then loosen the bolts and reposition the latch assembly as necessary. Following adjustment, retighten
the mounting bolts.
LICENSE
PLATE
10.12 The hood bumpers, located at the front of the hood, can
be screwed up or down to adjust the closed position of the hood
BUMPER
GUARDS
11.3a
Typical front bumper details
BUMPER
MOUNTING
EXTENSION
HOOK
TOW
HOOK
BUMPER
MOUNTING
HOOK
BRACKET
1 1.3b Cherokee rear bunnper details
GUARDS
BUMPER
RAIL (WITH_
SWING-OUT
SPARE TIRE)
The Motor Manual Guy
Chapter 11
1 1 The rear of the hood can also be adjusted up-and-down so it is
flush with the fenders. To do this, loosen the hood-to-hinge bolts and
add or subtract adjusting shims, which are available at your dealer.
12 Finally, adjust the hood bumpers so the hood, when closed, is flush
with the fenders (see illustration).
13 The hood latch assembly, as well as the hinges, should be periodically lubricated with white lithium-base grease t o prevent sticking and
wear.
Body
an assistant support the bumper as the bolts are removed.
3 Remove the bolts that secure the bumper mounting brackets t o
the frame, then detach the bumper (see illustrations).
4 Installation is the reverse of removal.
5 Tighten the retaining bolts securely.
6 Install any components that were removed.
12
11
Bumpers
removal and installation
Refer to illustrations 1 1.3a, 1 1.3b and 11.3c
1 Disconnect any wiring or other components that would interfere
with bumper removal.
2 Supp~rt the bumper with a jack or jackstand. Alternatively, have
11-7
Door trim panel - removal and installation
Refer to illustrations 12. 2a, 12.2b, 12.3 and 12.4
1 Disconnect the negative cable from the battery.
2 Remove the armrest and door handle assemblies (see illustrations).
3 On manual window regulator equipped models, remove the crank
handle (see illustration). On power reaulator
models, pry out the control
switch assembly and unplu~ it.
11.3c Typical Comanche
rear bumper details
1 Bumper rail
2 License plate light
bulb housings
3 Bumper extensions
4 Anti-skid plates
5 Bumper mounting brackets
6 License plate lights and wires
B
PANEL
1,1
ARMREST
RETAINING
SCREWS
12.2a Remove the two armrest
retaining scraws . . .
12.2b . . . remove the three door
handle/bezel screws (A), detach the rod
links (Bl, then remove the door handle
12.3
Pry off the crank handle
The Motor Manual Guy
Chapter 11
11-8
Body
!':1
:'I
i
.
'
/; J,
I /l
')
'
I
HINGE
PLATES
I
ADJUSTMENT
SHIMS
12.4 A flat, forked tool such as this one makes door
panel removal much easier because the long ribbed plastic
retainers are difficult t o pry out
4 Insert a flat, forked tool or a putty knife between the trim panel
and the door and disengage the ribbed plastic retainers (see illustration).
Work around the outer edge until the panel is free.
5 Once all of the retainers are disengaged, detach the trim panel,
unplug any wire harness connectors and remove the trim panel from
the vehicle.
6 For access to the inner door, carefully peel back the plastic watershield.
7 Prior to installation of the door panel, be sure to reinstall any retainers in the panel which may have come out during the removal procedure and remain in the door itself.
8 Plug in the wire harness connectors and place the panel in position
in the door. Press the door panel into place until the clips are seated
and install the handle and armrest assemblies, Install the manual
regulator window crank or power window switch assembly.
13 Door - removal, installation and adjustment
13.6 Forward-and-backward adjustments are made by
adding or subtracting adjustment shims between the door
and hinge plates
5
Installation is the reverse of removal. Tighten the hinge-to-door
bolts t o the specified torque.
6 Following installation of the door, check the alignment and adjust
it if necessary as follows:
a) Forward-and-backward adjustments are made by adding or removing as necessary (see illustrations).
b) The door lock striker can also be adjusted both up-and-down and
sideways to provide positive engagement with the lock mechanism. This is done by loosening and moving the striker as necessary.
-
Refer to illustrations 13. and 13.6
Remove the door trim panel (see Section 12). Disconnect any wire
harness connectors and push them through the door opening so they
won't interfere with door removal. Remove the door check pin (see
illustration).
2 Place a jack or jackstand under the door or have an assistant on
hand to support it when the hinge bolts are removed. Note: If a jack
or jackstand is used, place a rag between it and the door to protect
the door's painted surfaces.
3 Scribe around the door hinges.
4 Remove the hinge-to-door bolts (a #30 Torx head tool is required)
and carefully lift off the door.
13.1 Remove the door check pin (arrow)
14
Liftgate (Cherokee models)
and adjustment
- removal,
installation
Refer to illustrations 14.4, 14.5 and 14.8
1 Open the liftgate and cover the upper body area around the opening
with pads or cloths to protect the painted surfaces when the liftgate
is removed.
2 Detach the left side cargo area trim panel and unplug the electrical
connector for the liftgate wiring harness.
3 Paint or scribe around the hinge flanges so the liftgate can be easily
adjusted when installed.
4 While an assistant supports
the liftgate, detach the support struts
. .
(see illustration).
14.4 Detach the wire retainer with a small screwdriver
and pry the end of the support strut off the ballstud
The Motor Manual Guy
Chapter 11
Body
11-9
14.8
14.5
A #30 Torx head tool will be required to remove the
hinge bolts
Liftgate striker and shim details
end of the support from the retaining dowel (see illustration).
2 Pull the right side of the tailgate rearward t o disengage the right
hinge, then pull the tailgate t o the right to disengage the left hinge.
5 Remove the hinge bolts (a Torx head tool is necessary) and detach
the liftgate from the vehicle (see illustration).
6 Installation is the reverse of removal. Tighten the hinge bolts securely.
7 After installation, close the liftgate and make sure it's in proper
alignment with the surrounding body panels. Adjustments are made
by adding or removing shims (available at your dealer) between the
hinge and liftgate or roof panel.
8 The engagement of the liftgate can be adjusted by removing the
screws and the striker and adding or removing shims underneath t o
raise or lower it (see illustration). If you add or remove shims, tighten
the striker screws to the specified torque.
With the tailgate in the open (horizontal) position, engage the
female half of the left hinge (located on the tailgate) with the male half
(on the cargo box).
4 Force the right side of the tailgate forward until the halves of the
right hinge are engaged.
5 Pull the supports upward and engage the slots on their ends with
the retaining dowels, then force the supports down t o seat them.
15 Tailgate (Comanche models) - removal and installation
Refer to illustrations 16.2, 16.4, 16.7 and 16.10
1
Disconnect the negative cable at the battery.
Refer to illustrations 75.la and 15.1b
Lower instrument panel
Removal
1
Lower the tailgate and pull the centers of the supports up (see illustration). Push each support forward to disengage the slot on the
Installation
3
16 Dashboard panels - removal and installation
2 Remove the retaining screws, lower the panel, unplug any electrical
connectors and remove the panel (see illustration).
3 Installation is the reverse of removal.
LOWER INSTRUMENT
PANEL
15.1a Pull the center of each tailgate
support up
...
15.1 b . . . then disengage the slot on
the end of the support from the
retaining dowel
16.2 Remove the retaining screws
from the lower instrument panel
The Motor Manual Guy
Chapter 11 Body
61-10
BEZEL
ATTACHING
SCREWS
SNAP FIT
LOCATION
\
,
\I
/ DEFROSTER COWL
RETAININr CL~'
I
~-\
SNAP FIT
LOCATIONS
16.4
The instrument cluster bezel is held in place by four
screws and is a snap fit
The left side of the defroster cowl is retained by a clip
Defroster cowl panel
Instrument cluster bezel
4
fit
5
6
16.10
Remove the attaching screws and unsnap the bezel at the snap
locations in the dash (see illustration).
Remove the bezel.
lnstallation is the reverse of removal.
Radio and heater control panel
7 Remove the attaching screws and pull the panel assembly out (see
illustration).
8 Unplug the electrical connectors and remove the assembly.
9 Installation is the reverse of removal.
10 Remove the screws, detach the retaining clip on the driver's side
and lift the c o w l panel out (see illustration).
11 Installation is the reverse of removal.
17
Center console - removal and installation
Refer to illustration 1 7.3a, 1 7.36, 1 7.4a and 1 7.46
1
Disconnect the negative cable at the battery.
~
'\
DEFROSTER COWL
PANEL
RADIO AND
HEATER CONTROL
PANEL
16.7
Dashboard panel installation details
The Motor Manual Guy
Chapter 11 Body
Pry up on the corner of the
transmission shift boot t o detach it
(manual transmission shown, automatic
transmission similar)
11-11
17.4a Locations of the t w o front
console retaining screws (arrows)
If you have a 4WD vehicle, also
detach the transfer case shift plate
2 On vehicles with automatic transmission, remove the shift handle
by grasping it securely and pulling straight up. On vehicles with manual
transmission, remove the shift knob by loosening the locknut with a
wrench, then unscrewing the shift knob by hand.
3 Remove the transmission shift boot or plate by prying up at the
corner with a small screwdriver (see illustration). On 4WD vehicles,
also remove the transfer case shift plate (see illustration).
4 Remove the retaining screws or bolts (see illustrations).
5 Detach the console and lift it from the vehicle.
6 Installation is the reverse of removal.
6
Center console component layout
I
2
3
4
5
6
7
8
9
11
Center panel retaining serews
Center panel
Console
Storage pocket
Storage pocket
Wing and rear panels
Ashtray and bracket
Compartment lid
Bottom panels
Heater air ducts
Brackets
11
The Motor Manual Guy
Chapter 11 Body
11-12
r
18 Door window glass
- removal and installation
Refer to illustrations 18.4, 18.5, 18.6, 18.8 and 18.9
1
Remove the door trim panel and watershield (see Section 12).
2 Lower the window glass.
3 Remove the door window hardware, weatherseal and moldings
as necessary for access.
Front door
4
Remove the glass channel bottom screw (see illustration).
Remove the vent window frame screws, tilt the window and frame
back and remove it (see illustration).
6 Remove the door glass attaching stud nut and spring washer, tilt
the glass to detach it from the stud, then remove the glass by pulling
it up and out of the door (see illustration).
7 Installation is the reverse of removal. Tighten the vent window
frame screws and stud nut securely.
5
Rear door
8
18.4
A Torx head tool is required when removing the
glass channel bottom screw (arrow)
Remove the window channel screws and stationary glass frame
screws, tilt the channel and frame forward and remove it from the door
(see illustration).
9 Remove the glass stud nut and wave washer (see illustration).
~==--STUD
~\~VENT
\\\
NUT
I
FRAME
1\ ~""
'
VENT WINDOW
18.5 Remove the front door vent window frame screws,
tilt the window and frame back and remove i t
.c=----__
CHANNEL
TOP
SCREW
\
SPRING
WASHER
\
DOOR GLASS
18.6 Front door glass attachment details
STATIONARY
WAVE WASHER
D NUT
WINDOW
CHANNEL
CHANNEL
BOTTOM
SCREW
18.8 Rear door stationary glass frame and window
channel attachment details
18.9 Rear door glass attachment details
I
•
The Motor Manual Guy
11-13
Chapter 11 Body
10 Remove the window glass by ·tilting it to detach the stud, then
sliding the glass up and out of the door.
1 1 lnstallation is the reverse of removal. Tighten the stationary glass
frame screws and stud nut securely.
solenoid (see illustration). On power door locks, it will be necessary
to drill out the rivets retaining the solenoid to the door.
5 lnstallation is the reverse of removal. Tighten the door latch retaining screws securely.
Lock cylinder
Refer to illustrations 19.3,19.4,19.6 and 19.8
1 Remove the door trim panel and watershield (see Section 12).
2 Remove the door window glass (see Section 18).
Disconnect the link from the lock cylinder (see illustration).
Use pliers t o slide the retaining clip off and remove the lock cylinder
from the door. lnstallation is the reverse of removal. After installation,
check the latch link freeplay by pressing the door handle release button
in. Check that the latch link starts to move after the button moves about
1164-inch. If necessary, loosen the adjusting screw on the latch, adjust
the freeplay and then retighten it.
Door latch
Handle
3
8 Remove the retaining nuts, pull the handle out, detach the control
rod and remove the handle from the door (see illustration).
9 lnstallation is the reverse of removal. Tighten the retaining nuts
securely.
19 Door latch, lock cylinder and handle
- removal
and installation
Remove the access plug (if equipped) in the end of the door (see
illustration).
4 Remove the three door latch retaining screws from the end of the
door, disconnect the links, then remove the latch and (if equipped)
6
7
ACCESS
PLUG
19.4 Door latch and lock details
19.3 On some models it is necessary
to pry out the plug i n the end of the
door for access t o the door handle
I Latch retaining screws
2 Latch assembly
3 Power lock solenoid
4 Lock cylinder and clip
11•·...
the handle out,
19.8 Remove the retaining nuts (1), pull(2)
19.6
Lock cylinder installation details
then detach the control rod
.I
The Motor Manual Guy
Chapter 11 Body
11-14
20.2
20.3
Remove the retaining screw, pull out the trim cover
Three bolts (arrows) retain the mirror to the door
(1), loosen the adjustment knob set screw (2) and detach
the panel from the door
20
Outside mirror
- removal and installation
21
Seats - removal and installation
Refer to illustration 20.2, 20.3 and 20.5
Refer to illustrations 2 1.2, 2 1.4a, 2 1.4b and 2 1.7
Standard mirror
Front seat
1 Remove the door trim panel (see Section 12).
2 Remove the retaining screw, pull out the trim cover, loosen the
adjustment knob set screw and pull off the trim cover (see illustration).
3 Remove the three retaining bolts and lift off the mirror (see illustration).
4 Installation is the reverse of removal.
Remove the seat frame trim panels.
Remove the retaining nuts, unplug any electrical connectors and
lift the seats from the vehicle (see illustration).
3 Installation is the reverse of removal. Tighten the retaining nuts
t o the specified torque.
1
2
Rear seat
Low profile mirror
Bottom cushion
5
4 Pull up on the bottom cushion release strap, tilt the cushion forward, then unlock the frame release lever and lift the assembly out
(see illustrations).
Remove the three retaining bolts and lower the mirror assembly
from the vehicle (see illustration).
6 Installation is the reverse of removal.
I
20.5
The low profile mirror (1) is retained by three bolts (2)
21.2
The front seats are retained by four nuts (arrows)
The Motor Manual Guy
Chapter 11 Body
21.4b
21.4a
Pull up on the bottom cushion release strap (arrow)
11-15
...
tilt the cushion forward, then unlock the frame
release lever (arrow)
...
5 To install the cushion, place the cushion assembly in position, insert
the left pivot shaft into the receptacle, snap the release lever in place
and swing the seat down.
Seatback cushion
6 Remove the bottom cushion (see above), remove the seatbelts from
their elastic straps, then release the seatback lock.
7 Remove the pivot bolts and washers, move the cushion forward,
then lift it from the vehicle (see illustration).
8 To install the cushion, set it in place and install the pivot bolts and
washers. Tighten the bolts to the specified torque. Lock the seatback
in position, insert the seatbelts through the elastic straps and install
the bottom cushion.
21.7
The seatback cushion pivot bolts (arrow) are located
at the base of the cushion
The Motor Manual Guy
Chapter 12
Chassis electrical system
Contents
Battery check and maintenance
Battery
removal and installation
Bulb replacement
Brake light switch replacement and adjustment .
Cruise control system.description and check .
Circuit breakers
general information
Electrical troubleshooting.general information
Fuses
general information
Fusible links
general information
General information
Headlights
removal and installation
Headlights
adjustment
Headlight switch
removal and installation . . .
Ignition switch
removal and installation
Instrument cluster
removal and installation
Instrument panel
removal and installation
Neutral start switch.removal, installation
and adjustment
See Chapter
description and check
Power door lock system
Power window system
description and check
Relays
general information
check and replacment
Turn signal and hazard flashers
removal and installation
Turn signal switch
Wiper motors
removal and installation
Wiring diagrams
general information
See Chapter 1
See Chapter 5
13
See Chapter 9
17
5
2
3
4
1
11
12
10
8
15
16
78
18
19
6
7
9
14
20
Specifications
Light bulb application
Number
Underhood light
Front park/turn signal light
Front side marker light
Headlight
Single
Dual
High beam .................................. .
Low beam .................................. .
License plate light
Cherokee
With swing-out spare tire
Without swing-out spare tire
Comanche
With step bumper
Without step bumper
Stopltail light
Rear turn signal light
Side marker light
Backup light
90
1
General information
The electrical system is a 12-volt, negative ground type. Power for
the lights and all electrical accessories is supplied by a leadlacid-type
battery which is charged by the alternator .
This Chapter covers repair and service procedures for the various
2057NA
194
H6052
H4701
H4703
168
67
194
67
2057
1156
97
1156
electrical components not associated with the engine Information on
the battery. alternator. distributor and starter motor can be found in
Chapter 5.
It should be noted that when portions of the electrical system are
serviced. the negative battery cable should be disconnected from the
battery to prevent electrical shorts and/or fires
The Motor Manual Guy
Chapter 12 Chassis electrical system
2 Electrical troubleshooting
general information
A typical electrical circuit consists of an electrical component, any
switches, relays, motors, fuses, fusible links or circuit breakers related
t o that component and the wiring and connectors that link the component to both the battery and the chassis. To help you pinpoint an
electrical circuit problem, wiring diagrams are included at the end of
this book.
Before tackling any troublesome electrical circuit, first study the appropriate wiring diagrams t o get a complete understanding of what
makes up that individual circuit. Trouble spots, for instance, can often
be narrowed down by noting if other components related to the circuit
are operating properly. If several components or circuits fail at one time,
chances are the problem is in a fuse or ground connection, because
several circuits are often routed through the same fuse and ground
connections.
Electrical problems usually stem from simple causes, such as loose
or corroded connections, a blown fuse, a melted fusible link or a bad
relay. Visually inspect the condition of all fuses, wires and connections in a problem circuit before troubleshooting it.
If testing instruments are going t o be utilized, use the diagrams to
plan ahead of time where you will make the necessary connections
in order t o accurately pinpoint the trouble spot.
The basic tools needed for electrical troubleshooting include a circuit
tester or voltmeter (a 12-volt bulb with a set of test leads can also
be used), a continuity tester, which includes a bulb, battery and set
of test leads, and a jumper wire, preferably with a circuit breaker incorporated, which can be used to bypass electrical components. Before
attempting t o locate a problem with test instruments, use the wiring
diagram(s) t o decide where to make the connections.
Voltage checks
Voltage checks should be performed if a circuit is not functioning
properly. Connect one lead of a circuit tester t o either the negative
battery terminal or a known good ground. Connect the other lead t o
a connector in the circuit being tested, preferably nearest t o the battery
or fuse. If the bulb of the tester lights, voltage
- is present, which means
that the part of the circuit between the connector and the battery is
problem free. Continue checking the rest of the circuit in the same
fashion. When you reach a point at which no voltage is present, the
problem lies between that point and the last test point with voltage.
Most of the time the problem can be traced to a loose connection. Note:
Keep in mind that some circuits receive voltage only when the ignition
key is in the Accessory or Run position.
12-1
Finding an open circuit
When diagnosing for possible open circuits, it is often difficult t o
locate them by sight because oxidation or terminal misalignment are
hidden by the connectors. Merely wiggling a connector on a sensor
or in the wiring harness may correct the open circuit condition.
Remember this when an open circuit is indicated when troubleshooting
a circuit. Intermittent problems may also be caused by oxidized or loose
connections.
Electrical troubleshooting is simple if you keep in mind that all electrical circuits are basically electricity running from the battery, through
the wires, switches, relays, fuses and fusible links t o each electrical
component (light bulb, motor, etc.) and to ground, from which it is
passed back t o the battery. Any electrical problem is an interruption
in the flow of electricity to and from the battery.
3 Fuses
- general information
Refer to illustrations 3. 1 and 3.3
The electrical circuits of the vehicle are protected by a combination
of fuses, circuit breakers and fusible links. The fuse block is located
under the instrument panel on the left side of the dashboard (see
illustration).
Each of the fuses is designed to protect a specific circuit, and the
various circuits are identified on the fuse panel itself.
Miniaturized fuses are employed in the fuse block. These compact
fuses, with blade terminal design, allow fingertip removal and replacement. If an electrical component fails, always check the fuse first. A
blown fuse is easily identified through the clear plastic body. Visually
inspect the element for evidence of damage (see illustration). If a continuity check is called for, the blade terminal tips are exposed in the
fuse body.
Be sure t o replace blown fuses with the correct type. Fuses of different ratings are physically interchangeable, but only fuses of the proper rating should be used. Replacing a fuse with one of a higher or
lower value than specified is not recommended. Each electrical circuit
Finding a short
One method of finding shorts in a circuit is to remove the fuse and
connect a test light or voltmeter in its place to the fuse terminals. There
should be no voltage present in the circuit. Move the wiring harness
from side-to-side while watching the test light. If the bulb goes on,
there is a short to ground somewhere in that area, probably where the
insulation has rubbed through. The same test can be performed on each
component in the circuit, even a switch.
HAZARD
FLASHER
3.1
The fuse block is located under the left side of the
instrument panel
Ground check
Perform a ground test to check whether a component is properly
grounded. Disconnect the battery and connect one lead of a selfpowered test light, known as a continuity tester, to a known good
ground. Connect the other lead to the wire or ground connection being
tested. If the bulb goes on, the ground is good. If the bulb does not
go on, the ground is not good.
Continuity check
A continuity check is done t o determine if there are any breaks in
a circuit - if it is passing electricity properly. With the circuit off (no
power in the circuit), a self-powered continuity tester can be used to
check the circuit. Connect the test leads to both ends of the circuit
(or to the "power" end and a good ground), and if the test light comes
on the circuit is passing current properly. If the light doesn't come on,
there is a break somewhere in the circuit. The same procedure can
be used t o test a switch, by connecting the continuity tester t o the
switch terminals. With the switch turned On, the test light should come
on.
3.3 To check for a blown fuse, pull it out and inspect it
visually for an open (1 ), then with the circuit activated. use
a test light across the points shown (2)
The Motor Manual Guy
Chapter 12
12-2
Chassis electrical system
needs a specific amount of protection. The amperage value of each
fuse is molded into the fuse body.
If the replacement fuse immediately fails, don't replace it again until
the cause of the problem is isolated and corrected. In most cases, the
cause will be a short circuit in the wiring caused by a broken or deteriorated wire.
4 Fusible links - general information
Some circuits are protected by fusible links. The links are used in
circuits which are not ordinarily fused, such as the ignition circuit.
Although the fusible links appear to be a heavier gauge than the wire
they are protecting, the appearance is due to the thick insulation. All
fusible links are four wire gauges smaller than the wire they are designed
to protect.
Fusible links cannot be repaired, but a new link of the same size wire
can be put in its place. The procedure is as follows:
a) Disconnect the negative cable from the battery.
b) Disconnect the fusible link from the wiring harness.
c) Cut the damaged fusible link out of the wiring just behind the
connector.
d) Strip the insulation back approximately 112-inch.
e) Position the connector on the new fusible link and crimp it into
place.
f) Use rosin core solder at each end of the new link to obtain a good
solder joint.
g) Use plenty of electrical tape around the soldered joint. No wires
should be exposed.
h) Connect the battery ground cable. Test the circuit for proper
operation.
5
Circuit breakers
-
7
Turn signal and hazard flashers
- check and replacement
Turn signal flasher
1 The turn signal flasher, a small canister-shaped unit located in the
fuse block (see illustration 3.1), flashes the turn signals.
2 When the flasher unit is functioning properly, an audible click can
be heard during its operation. If the turn signals fail on one side or the
other and the flasher unit does not make its characteristic clicking
sound, a faulty turn signal bulb is indicated.
3 If both turn signals fail to blink, the problem may be due to a blown
fuse, a faulty flasher unit, a broken switch or a loose or open connection.
If a quick check of the fuse box indicates that the turn signal fuse has
blown, check the wiring for a short before installing a new fuse.
4 To replace the flasher, simply pull it out of the fuse block.
5 Make sure that the replacement unit is identical t o the original.
Compare the old one t o the new one before installing it.
6 Installation is the reverse of removal.
Hazard flasher
7 The hazard flasher, a small canister-shaped unit located in the fuse
block, flashes all four turn signals simultaneously when activated.
8 The hazard flasher is checked in a fashion similar to the turn signal
flasher (see Steps 2 and 3).
9 To replace the hazard flasher, pull it from the back of fuse block.
1 0 Make sure the replacement unit is identical to the one it replaces.
Compare the old one to the new one before installing it.
1 1 lnstallation is the reverse of removal.
general information
Circuit breakers protect components such as power windows, power
door locks and headlights. Some circuit breakers are located in the fuse
box.
On some models the circuit breaker resets itself automatically, so
an electrical overload in a circuit breaker protected system will cause
the circuit to fail momentarily, then come back on. If the circuit does
not come back on, check it immediately. Once the condition is corrected, the circuit breaker will resume its normal function. Some circuit
breakers must be reset manually.
-
6 Relays
If a faulty relay is suspected, it can be removed and tested by a dealer
service department or a repair shop. Defective relays must be replaced
as a unit.
general information
Refer to illustration 6.2
Several electrical accessories in the vehicle use relays to transmit
the electrical signal t o the component. If the relay is defective, that
component will not operate properly.
The various relays are grouped together i n several locations (see
illustration).
8
Ignition switch
removal and installation
Refer to illustrations 8.Ba and 8.Bb
1 Disconnect the negative cable at the battery.
Removal
2 The ignition switch is located on the lower end of the steering column and is connected by an actuating rod t o the key lock assembly
3 Remove the lower dashboard trim panel (see Chapter 11).
4 Set the key lock in the Off-Lock position.
5 Remove the t w o screws retaining the switch to the steering column and disconnect the actuating rod.
6 Unplug the black harness electrical connector from the white connector and remove the switch from the steering column.
Ins talla tion
7 Place the switch in position.
8 Move the slider on the switch to the Accessory position (see illustrations). On standard columns, the Accessory position is t o the
SLIDER HOLE
L--------- ON
L---------- OFF
L..-------- OFF-LOCK
.__-------ACCESSORY
6.2
Three of the relays (arrows) are located in the engine
compartment adjacent t o the battery, under a cover
8.8a
Standard steering column ignition switch details
The Motor Manual Guy
Chapter 12
Chassis electrical system
extreme left. On tilt columns, the Accessory position is on the extreme
right.
9 Connect the actuating rod to the slider hole and install the switch
with the screws finger tight.
1 0 Hold the key lock in the Accessory position, push the switch toward
the bottom of the column slightly to remove any slack in the rod and
tighten the retaining screws securely.
11 Plug in the connector and install the dashboard trim panel.
9
Turn signal switch - removal and installation
Refer to illustrations 9.4 and 9.9
1 Disconnect the negative battery cable and remove the steering
wheel as detailed in Chapter 10.
2 Remove the lower trim cover located at the base of the dashboard
(see Chapter 1 1 ).
3 At the end of the steering column, some models have a plastic
cover plate which should be pried out of the column using a screwdriver
in the slots provided.
4 The lock plate will now have t o be removed from the steering column. This is held in place with a snap-ring which fits into a groove
in the steering shaft. The lock plate must be depressed t o relieve
pressure on the snap-ring. A special U-shaped tool which fits on the
shaft should be used to depress the lock plate as the snap-ring is removed from its groove (see illustration).
5 Slide the cancelling cam, upper bearing repload spring and thrust
washer off the end of the shaft.
12-3
6
Remove the turn signal lever attaching screw and withdraw the
turn signal lever from the side of the column.
7 Remove the hazard warning knob.
8 Remove the turn signal assembly mounting screws.
9 Remove the nuts and bolts retaining the steering column t o the
bracket (see illustration). Loosen the column brace mounting nut at
the driver's side kick panel. This will allow the column to drop, providing
clearance for switch and wiring removal.
10 Pull the switch wiring connector out of the bracket on the steering
column jacket. Tape the connector terminals to prevent damage. Feed
the wiring connector up through the column support bracket and pull
the switch, wiring harness and connectors out the top of the steering
column.
1 1 Installation is a reversal of removal; however, make sure the wiring
harness is in the protector as it is pulled into position. Before installing
the thrust washer, upper bearing preload spring and cancelling cam,
make sure the switch is in the neutral position and the warning knob
is pulled out. Always use a new snap-ring on the shaft for the lock plate.
-
10 Headlight switch - removal and installation
Refer to illustrations 70.3 and 7 0.4
1 Disconnect the negative cable at the battery.
2 Pull the headlight switch out to the On position.
3 Reach up under the dash panel, push the retainer button, then pull
the control shaft out of the switch (see illustration).
LOCKPLATE
ACCESSORY
OFF-LOCK
OFF-------ON--------,
START-
SLIDER HOLE
9.4
8.8b
Tilt steering column ignition switch details
With the lockplate compressed, pry out the snap-ring
with a screwdriver
(
0
VIEWED FROM UNDERSIDE OF DASH
9.9
Remove the steering column nuts and bolts so the
column can be lowered
10.3 Reach up under the dash panel, push the retainer
button and pull the control shaft out of the switch
12
The Motor Manual Guy
Chapter 12 Chassis electrical system
12-4
RETAINER BUTTON
FERRULE NUT
\
CONTROL
SHAFT
10.4
Headlight switch component layout
4 Unplug the electrical connector, unscrew the ferrule nut and
remove the switch from the instrument panel (see illustration).
5 To install the switch, plug in the electrical connector, place the
switch in position and install the ferrule nut. Insert the shaft into the
switch until it is seated.
11.2a
11
Headlights - removal and installation
Single headlight installation details
3 Headlight
4 Headlight bucket
1 Headlight bezel
2 Headlight retainer
Refer to illustrations 1 1.2a and 1 1.2b
1 Disconnect the negative cable from the battery.
2 Remove the retaining screws and detach the headlight bezel (see
illustrations).
3 Remove the headlight retainer screws, taking care not t o disturb
the adjustment screws.
4 Remove the retainer and pull the headlight out enough to allow
the connector to be unplugged.
5 Remove the headlight.
6 To install the headlight, plug the connector in, place the headlight
in position and install the retainer and screws. Tighten the screws
securely.
7 Place the headlight bezel in position and install the retaining screws.
2
3
5
1 2 Headlights - adjustment
Refer to illustrations 12. l a and 12.1b
Note: The headlights must be aimed correctly. If adjusted incorrectly
they could blind the driver of an oncoming vehicle and cause a serious
accident or seriously reduce your ability to see the road. The headlights
should be checked for proper aim every 12 months and any time a new
headlight is installed or front end body work is performed. It should
be emphasized that the following procedure is only an interim step
which will provide temporary adjustment until the headlights can be
adjusted by a properly equipped shop.
1 1.2b
1
2
3
4
Headlight
Headlight
Headlight
Headlight
bezel
retainer
(low beam)
adjusters
5 Headlight buckets
6 Headlight (high beam}
7 Side marker light
2
4
2
Dual headlight installation details
3
3
4
I
12. 1a
Single headlight adjustment screw details
Left-and-right adjusting
screw (right headlight}
2 Up-and-down adjusting
screw
3 Left-and-right adjusting
screw (left headlight}
4 Headlight retainer screws
12.1 b
Dual headlight adjustment screw details
Left-and-right adjusting screw
(right headlight}
2 Up-and-down adjusting screw
3 Left-and-right adjusting screw
(left headlight)
I
J
The Motor Manual Guy
Chapter 12 Chassis electrical system
13.1a
13. b
Front turn signallparking light bulb replacement details
12-5
Side marker light housing removal details
CLIP
0
13.1c
Cherokee tail light housing
removal details
13.1d
Comanche tail light housing
removal details
13.1 e Comanche license plate bulb
replacement details
GASKET
LICENSE PLATE BULB
HOUSING
LENS
\
~--
,,;-,. . -
~
13. l f
Cherokee license plate bulb replacement details
(without swing-out spare tire)
1 Headlights have t w o spring loaded adjusting screws, one on the
top controlling up-and-down movement and one on the side controlling
left-and-right movement (see illustrations).
2 There are several methods of adjusting the headlights. The simplest
method requires a blank wall 25 feet in front of the vehicle and a level
floor.
3 Position masking tape vertically on the wall in reference to the vehicle centerline and the centerlines of both headlights.
4 Position a horizontal tape line in reference to the centerline of all
the headlights. Note: It may be easier to position the tape on the wall
with the vehicle parked only a few inches away.
5 Adjustment should be made with the vehicle sitting level, the gas
tank half-full and no unusually heavy load in the vehicle.
6 Starting with the low beam adjustment, position the high intensity
zone so it is t w o inches below the horizontal line and t w o inches t o
13.1 g Cherokee license plate
bulb replacement details (with
swing-out spare tire)
the right of the headlight vertical line. Adjustment is made by turning
the top adjusting screw clockwise to raise the beam and counterclockwise to lower the beam. The adjusting screw on the side should be
used in the same manner to move the beam left or right.
7 With the high beams on, the high intensity zone should be vertically
centered with the exact center just below the horizontal line. Note:
It may not be possible to position the headlight aim exactly for both
high and low beams. If a compromise must be made, keep in mind that
the low beams are the most used and have the greatest effect on driver
safety.
8 Have the headlights adjusted by a dealer service department or
service station at the earliest opportunity.
1 3 Bulb replacement
Refertoillustrations 13. la, 13. Ib, 13.1c, 13.1d, 13. le, 13. 1f, 13.1g
and 13.3
1 The lenses of many lights are held in place by screws, which makes
it a simple procedure to gain access t o the bulbs (see illustrations).
The Motor Manual Guy
Chapter 12 Chassis electrical system
12-6
13.3 To remove a bulb housing, rotate the housing
counterclockwise about so• and pull it out
14.2 Pry up on the locking lever with a small screwdriver,
2 On some lights the lenses are held in place by clips. The lenses
can be removed either by unsnapping them or by using a small
screwdriver to pry them off.
3 Some bulbs, such as the tail light bulbs, are located in bulb housings. To remove a bulb housing, rotate the housing counterclockwise
about 60° and pull it out (see illustration).
4 Several types of bulbs are used. Some are removed by pushing
in and turning them counterclockwise. Others can simply be unclipped
from the terminals or pulled straight out of the socket.
5 To gain access to the instrument panel lights, the instrument cluster
will have t o be removed first.
the wiper arms off the pivots (see illustration).
3 Remove the cowl trim cover retaining screws, then detach the
cover for access to the motor.
4 Disconnect the washer hoses.
5 Remove the bracket nuts and the pivot pin screws (see illustration). Unplug the electrical connector and remove the assembly from
the vehicle. Be careful not to damage the rubber waterproof boot shroud
when handling the motor assembly.
6 Installation is the reverse of removal.
then pull the wiper arm off the pivot
Rear wiper
7
14 Wiper motors
removal and installation
Refer to illustrations 14.2, 14.5, 14.7 and 14.8
1 Disconnect the negative cable at the battery.
Windshield wiper
2
(
Use as small screwdriver to pry the locking levers up, then pull
Remove the wiper arm and disconnect the washer hose (see illustration).
8 Remove the pivot pin retaining nut and washers. Note the order
in which the washers are arranged for ease of installation (see illustration).
9 Open the liftgate and remove the trim panel.
1 0 Unplug the electrical connector, remove the t w o mounting screws
and lower the motor from the liftgate (see illustration).
11 Installation is the reverse of removal.
4a.
PIVOT PIN SCREWS (4)
I\
=3Mb:.1c,
(;o
\
I
\
14.5
The wiper assembly is held in place by four pivot pin
screws and t w o bracket nuts
14.7
Lift the tab t o release the wiper arm, then
disconnect the washer hose
The Motor Manual Guy
Chapter 12 Chassis electrical system
12-7
PIVOT PIN
INSTRUMENT CLUSTER
ATTACHING SCREWS
MOUNTING
SWITCH
HOUSINGS
SCREWS
14.8
CIGAR
LIGHTER
HOUSING
Rear wiper motor installation details
15.3
lnstrument cluster, switch housing and cigar lighter
screw locations
1 5 lnstrument cluster - removal and installation
Refer to illustration 15.3 and 15.4
1 Disconnect the negative cable at the battery.
2 Remove the instrument cluster bezel (see Chapter 1 1 ).
3 Remove the screws attaching the instrument cluster, cigar lighter
and (if equipped) switch housings (see illustration).
4 Pull the cluster out and disconnect the speedometer cable and the
electrical connectors (see illustration). On some later models it may
be necessary to remove the nut under the vehicle on the left side upper
suspension arm and disconnect the speedometer cable bracket to provide sufficient slack so the cluster can be pulled out. You can pull the
speedometer cable out of the instrument cluster after you press the
spring clip on the instrument cluster and squeeze the clip attached to
the cable (if equipped).
5 Detach the cluster from the instrument panel.
6 Installation is the reverse of removal.
16
lnstrument panel - removal and installation
Refer to illustration 16.4
1 Disconnect the negative cable at the battery.
2 Remove all the dashboard panels (see Chapter 11).
3 Remove the parking brake release handle (if equipped) and the
lower heater/air conditioning duct, which is located below the steering
column.
4 Loosen the mounting bolts, then rotate the instrument panel back
so you can disconnect the tubes, wires, cables and harnesses (see
illustration).
5 Make sure all instrument panel components are disconnected, then
lift the instrument panel from the vehicle.
6 Installation is the reverse of removal. Make sure none of the wires
DEFROSTER
TUBE
15.4 Disconnect the
speedometer cable (1) and the
electrical connectors (2)
HEATER
VACUUM
HARNESS
DEFROSTER
TUBE
ENGINE
CHECK
LIGHT
INSTRUMENT
PANEL
12
HEATER CONTROL
16.4 Loosen the mounting bolts, rotate the instrument panel
back, then disconnect the tubes, wires, cables and harnesses
I
The Motor Manual Guy
12-8
Chapter 12
Chassis electrical system
or hoses get pinched between components when the instrument panel
is rotated-back into position.
WIRE COLOR CODE CHART
COLOR
STANDARD
TRACER
COLOR
BK
BLACK
WT
PK
PINK
BR
BROWN
WT
RD
RED
WT
DB
DARK
BLUE
WT
TN
TAN
WT
DG
DARK
GREEN
\AIT
VT
VIOLET
\UT
GY
GRAY
BK
WT
WHITE
BK
LB
LIGHT
BLUE
BK
YL
YELLOW
BK
COLOR
17 Cruise control system - description and check
CODE
The cruise control system maintains vehicle speed with a vacuum
actuated servo motor located in the engine compartment, which is connected t o the throttle linkage by a cable. The system consists of the
servo motor, clutch switch, brake switch, control switches, a relay
and associated vacuum hoses.
Because of the complexity of the cruise control system and the
special tools and techniques required for diagnosis, repair should be
left to a dealer service department or a repair shop. However, it is possible for the home mechanic t o make simple checks of the wiring and
vacuum connections for minor faults which can be easily repaired.
These include:
a) lnspect the cruise control actuating switches for broken wires
and loose connections.
b) Check the cruise control fuse.
c) The cruise control system is operated by vacuum so it's critical
that all vacuum switches, hoses and connections are secure.
Check the hoses in the engine compartment for tight connections,
cracks and obvious vacuum leaks.
19 Power window system
- description and check
--
The power window system operates the electric motors mounted
in the doors which lower and raise the windows. The system consists
of the control switches, the motors (regulators), glass mechanisms and
associated wiring.
Because of the complexity of the power window system and the
special tools and techniques required for diagnosis, repair should be
left to a dealer service department or a repair shop. However, it is pos-
COLOR
STANDARD
TRACER
CODE
BK OR
WH-
. LG
OR
LIGHT
GREEN
BK
ORANGE
BK
.
WITH TRACER
I
20.4 This chart will help you identify wire colors from the
18 Power door lock system - description and check
The power door lock system operates the door lock actuators
mounted in each door. The system consists of the switches, actuators
and associated wiring. Since special tools and techniques are required
to diagnose the system, it should be left to a dealer service department
or a repair shop. However, it is possible for the home mechanic to make
simple checks of the wiring connections and actuators for minor faults
which can be easily repaired. These include:
a) Check the system fuse and/or circuit breaker.
b) Check the switch wires for damage and loose connections. Check
the switches for continuity.
c) Remove the door panel(s) and check the actuator wiring connections to see if they're loose or damaged. lnspect the actuator
rods (if equipped) to make sure they aren't bent or damaged. Inspect the actuator wiring for damaged or loose connections. The
actuator can be checked by applying battery power momentarily.
A clicking sound indicates the solenoid is operating properly.
li.'lJ-9tR
wiring diagrams that follow - the term tracer is used t o
designate a different-colored stripe on a wire
sible for the home mechanic to make simple checks of the wiring connections and motors for minor faults which can be easily repaired.
These include:
a) lnspect the power window actuating switches for broken wires
and loose connections.
b) Check the power window fuse/and or circuit breaker.
c) Remove the door panel(s) and check the power window motor
wires to see if they're loose or damaged. lnspect the glass mechanisms for damage which could cause binding.
20
Wiring diagrams
general information
Since it isn't possible t o include all wiring diagrams for every year
covered by this manual, the following diagrams are those that are
typical and most commonly needed.
Prior to troubleshooting any circuits, check the fuse and circuit
breakers (if equipped) t o make sure they're in good condition. Make
sure the battery is properly charged and check the cable connections
(Chapter 1 ).
When checking a circuit, make sure that all connectors are clean,
with no broken or loose terminals. When unplugging a connector, do
not pull on the wires. Pull only on the connector housings themselves.
Refer to the accompanying chart for the wire color codes applicable
t o your vehicle.
The Motor Manual Guy
12-9
LEGEND OF SYMBOLS USED ON WIRING DIAGRAMS
+
POSITIVE
~>--
CONNECTOR
-
NEGATIVE
~
MALE CONNECTOR
GROUND
>---
FEMALE CONNECTOR
~
---
~-n.-
FUSE
__.._
GANG FUSES WITH BUSS BAR
I
~
~
,,___.
fvvrwrw,
~
~
.........._
...........
~
....
__..,....,,._
:r:
~
.,._
--e............_
~
]I
~n
-M~
l
-00
~
~2~
CAPACITOR
OHMS
I
RESISTOR
VARIABLE RESISTOR
I
I
OPEN CONTACT
CLOSED CONTACT
CLOSED SWITCH
SPLICE IDENTIFICATION
THERMAL ELEMENT
TIMER
TIMER
!.J
'YY v1
I
~}--~
COIL
SPLICE
C.i:t...':I
....
I~~
sERIES RESISTOR
STEP UP COIL
DENOTES WlRE CONTINUES ELSEWHERE
DENOTES WlRE GOES TO ONE OF TWO
CIRCUITS
',
CIRCUIT BREAKER
•---H-•
n
~
MULTIPLE CONNECTOR
OPTIONAL
WIRING WITH
WIRING WITHOUT
"Y" WINDINGS
'
aa=aa
I'-.
~
-(5~
~
DIGITAL READOUT
SINGLE FILAMENT LAMP
DUAL FILAMENT LAMP
L.E.D. - LIGHT EMITTING DIODE
OPEN SWITCH
THERMISTOR
CLOSED GANGED SWITCH
GAUGE
OPEN GANGED SWITCH
SENSOR
FUEL INJECTOR
TWO POLE SINGLE THROW SWITCH
m
'-.../
PRESSURE SWITCH
DENOTES WlRE GOES THROUGH
BULKHEAD DISCONNECT
#36
SOLENOID SWITCH
~
DENOTES WlRE GOES THROUGH
STEERING COLUMN CONNECTOR
MERCURY SWITCH
~
DENOTES WlRE GOES THROUGH
INSTRUMENT PANEL CONNECTOR
T
~
DIODE OR RECTIFIER
.
G
~
L-...-......1
BY-DIRECTIONAL ZENER DIODE
MOTOR
DENOTES WlRE GOES THROUGH GROMMET
P"'
I
DENOTES WlRE GOES THROUGH GROMME'r
TO ENGINE COMPARTMENT
)
HEATED
HEATED GRID ELEMENTS
ELEMENTS
ARMATURE AND BRUSHES
j
The Motor Manual Guy
12-10-
mF2
TO TURN/HAZZARD SWITCH
5- 18BR----c~·~(=:;:___ __ 79 18BR----,
79
ASSEMBLY (SEE SH 47,49)
TO HEADLAMP
DIMMER SWITCH
(SEE SH 37,39)
TO TURN/HAZZARD SWITCH 578
18GY
ASSEMBLY (SEE SH 47,49)
5-...---
1
m
E4
16WT - - < ~ 7 6 16WT
mA1
* --~(<---78 18GY * ~
ms1
~:::?A ___
TO