TM-5-4320-258-34
TM 5-4320-258-34
D E P A R T M E N T
O F
T H E
A R M Y
T E C H N I C A L
M A N U A L
TECHNICAL MANUAL
DIRECT SUPPORT AND GENERAL SUPPORT
MAINTENANCE MANUAL
FOR
PUMP, CENTRIFUGAL, POL, GED, 6 IN., 1120 GPM
SKID-MOUNTED (BARNES MODEL US67CCG)
FSN 4320-409-8678
H E A D Q U A R T E R S ,
D E P A R T M E N T
A U G U S T
1 9 7 1
O F
T H E
A R M Y
TM 5-4320-258-34
WARNING
If conditions require emergency fuel tank repairs by welding or other methods involving heat or flame, take care
to assure that all gasoline fumes are purged from the tank before commencing the repair. Applying heat or flame to a
fuel tank containing gasoline residue may result in a violent explosion, causing injury or death to maintenance personnel.
Before performing maintenance, be sure the unit is not operating or subject to line pressures.
Do not operate the pump within an enclosed area without venting the exhaust gases to the outside. Exhaust
fumes contain carbon monoxide, an odorless, colorless, deadly poison.
Do not allow smoking or open flames in the vicinity of this pump.
When lifting the pumping unit, be-sure the lifting device has a capacity of at least 4000 lbs. Do not allow the
pumping unit to swing while suspended.
When using cleaning solvents, always provide adequate ventilation to prevent excessive inhalation of solvent
vapors.
TM 5-4320-258-34
TECHNICAL MANUAL
NO. 5-4320-258-34
}
HEADQUARTERS,
DEPARTMENT OF THE ARMY
WASHINGTON, D. C., 30 August 1971
DIRECT SUPPORT AND GENERAL SUPPORT
MAINTENANCE MANUAL
PUMP, CENTRIFUGAL, POL, GED, 6 IN., 1120 GPM,
SKID-MOUNTED
(BARNES MODEL US67CCG)
FSN 4320-409-8678
CHAPTER 1.
Section
Paragraph
Section
Paragraph
INTRODUCTION
Page
I.
General ..............................................................................................1-1
1-1
Scope .................................................................................................1-1
1-2
Forms and records .............................................................................1-1
1-3
Reporting of errors..............................................................................1-1
II.
Description and data...........................................................................1-1
1-4
Description .........................................................................................1-1
1-5
Differences between models...............................................................1-3
1-6
Identification and tabulated data .........................................................1-4
CHAPTER 2.
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
Section
I.
Repair parts, special tools, and equipment..........................................2-1
Paragraph
2-1
Special tools and equipment...............................................................2-1
2-2
Maintenance repair parts ....................................................................2-1
Section
II.
Troubleshooting..................................................................................2-1
Paragraph
2-3
General ..............................................................................................2-1
2-4
Direct support and general support maintenance troubleshooting........2-1
Section
III.
General maintenance .........................................................................2-2
Paragraph
2-5
General ..............................................................................................2-2
2-6
Cleanliness.........................................................................................2-2
2-7
Care of bearings .................................................................................2-2
2-8
Seals and gaskets ..............................................................................2-2
Section
IV.
Removal and installation of major components and auxiliaries ..........2-3
Paragraph
2-9
Centrifugal pump ................................................................................2-3
2-10
Engine ................................................................................................2-3
CHAPTER 3.
REPAIR OF ENGINE COMPONENTS
Section
I.
Repair of fuel system components
Paragraph
3-1
Description of fuel system...................................................................3-1
3-2
Fuel tank ............................................................................................3-2
3-3
Carburetor ..........................................................................................3-4
3-4
Governor ............................................................................................3-6
3-5
Engine overspeed governor................................................................3-8
Section
II.
Repair of cooling system components .............................................. 3-10
Paragraph
3-6
Description of cooling system ........................................................... 3-10
3-7
Radiator............................................................................................ 3-11
3-8
Water pump...................................................................................... 3-11
3-9
Coolant temperature safety switch ................................................... 3-13
Section
III.
Repair of oil system components ..................................................... 3-14
Paragraph
3-10
Description of engine oil system ....................................................... 3-14
3-11
Engine oil filter ................................................................................. 3-14
3-12
Engine oil pressure safety switch ..................................................... 3-16
i
TM 5-4320-258-34
Paragraph
Section
Paragraph
CHAPTER 4.
Section
Paragraph
Section
Paragraph
CHAPTER 5.
Paragraph
APPENDIX A
3-13
IV.
3-14
3-15
Page
Engine oil pressure adjustment ......................................................... 3-17
Repair of engine mounting ............................................................... 3-17
Description ...................................................................................... 3-17
Engine support ................................................................................. 3-17
BASIC ENGINE OVERHAUL
I.
Introduction and fits, tolerances, and wear limits ................................4-1
4-1
Introduction.........................................................................................4-1
4-2
Fits, tolerances, and wear limits..........................................................4-1
II.
Engine overhaul .................................................................................4-4
4-3
Cylinder head ....................................................................................4-5
4-4
Intake and exhaust valves ..................................................................4-7
4-5
Intake and exhaust manjfolds ........................................................... 4-10
4-6
Oil pan and filler blocks ................................................................... 4-12
4-7
Engine oil pump................................................................................ 4-14
4-8
Gear cover ....................................................................................... 4-16
4-9
Flywheel and flywheel housing.......................................................... 4-18
4-10
Pistons and connecting rods ............................................................ 4-19
4-11
Main bearings and crankshaft ........................................................... 4-23
4-12
Camshaft ......................................................................................... 4-25
4-13
Cylinder block .................................................................................. 4-26
REPAIR OF CENTRIFUGAL PUMP
5-1
General ..............................................................................................5-1
5-2
Check valve replacement ...................................................................5-1
5-3
Shaft seal replacement ......................................................................5-3
5-4
Centrifugal pump overhaul .................................................................5-5
REFERENCES
ii
TM 5-4320-258-34
LIST OF ILLUSTRATIONS
Number
1-1
1-2
1-3
2-1
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
4-22
5-1
5-2
Title
Page
Centrifugal pump, left front view ..................................................................................1-2
Centrifugal pump, right rear view .................................................................................1-3
Wiring diagram ............................................................................................................1-5
Engine removal ..........................................................................................................2-4
Operation of engine speed regulating system ..............................................................3-2
Fuel tank, exploded view ............................................................................................3-3
Carburetor, exploded view ...........................................................................................3-5
Governor, exploded view.............................................................................................3-7
Engine overspeed governor, showing adjustment points .............................................3-9
Engine overspeed governor and related parts, exploded view .....................................3-9
Coolant temperature and oil pressure safety switches................................................ 3-10
Water pump, exploded view ..................................................................................... 3-12
Coolant temperature and oil pressure safety switches, exploded view ....................... 3-13
Engine oil filter mounting, exploded view .................................................................. 3-15
Engine oil filter, exploded view .................................................................................. 3-16
Engine mounting parts, exploded view....................................................................... 3-18
Cylinder head, exploded view ......................................................................................4-6
Cylinder head cap screw tightening sequence..............................................................4-7
Valves and camshaft, exploded view ..........................................................................4-8
Valve guide installation dimensions .............................................................................4-9
Narrowing valve seat ................................................................................................. 4-10
Intake and exhaust manifolds, exploded view ............................................................ 4-11
Oil pan and filler blocks, exploded view ..................................................................... 4-13
Engine oil pump, exploded view ............................................................................... 4-15
Gear cover and front end plate, exploded view ......................................................... 4-17
Checking flywheel runout .......................................................................................... 4-18
Checking flywheel eccentricity ................................................................................... 4-18
Checking flywheel housing runout ............................................................................. 4-19
Checking flywheel housing eccentricity ...................................................................... 4-19
Piston, crankshaft, and flywheel, exploded view ....................................................... 4-20
Checking piston fit in cylinder bore ........................................................................... 4-22
Removing upper bearing shell with angular pin ......................................................... 4-23
Checking bearing clearance with plastigage .............................................................. 4-24
Installing upper bearing half, using angular pin .......................................................... 4-24
Checking bearing clearance with shim stock .............................................................. 4-25
Timing gears showing alinement marks .................................................................... 4-26
Checking for insufficient timing gear clearance ......................................................... 4-26
Cylinder block and flywheel housing, exploded view .................................................. 4-28
Suction and discharge assemblies, exploded view ......................................................5-2
Centrifugal pump, exploded view.................................................................................5-4
iii
TM 5-4320-258-34
CHAPTER 1
INTRODUCTION
SECTION I. GENERAL
1-1.
Scope
These instructions are published for use by personnel to
whom the Barnes Manufacturing Company Model
US67CCG Centrifugal Pump is issued. They provide
information on the Direct and General maintenance of
the equipment as allocated by the Maintenance
Allocation Chart.
1-2.
Forms and Records
Maintenance forms, records, and reports which are used
by maintenance personnel at all maintenance levels are
listed in and prescribed.
1-3.
Reporting of Errors
Report of errors, omissions, and recommendations for
improving this publication by the individual user is
encouraged. Reports should be submitted on DA Form
2028, Recommended Changes to Publications, and
forwarded directly to Commanding General, U. S.
Army Mobility Equipment Command, ATTN: AMSMEMP, 4300 Good-fellow Boulevard, St.
Louis, Mo.
63120.
Section II. DESCRIPTION AND DATA
pump mounted on a welded skid base. The torque from
the engine is transferred to the pump through a flexible
coupling.
1-4.Description
a. Centrifugal Pump, Model US67CCG,
consists primarily of a gasoline engine and a centrifugal
1-1
TM 5-4320-258-34
Figure 1-1. Centrifugal pump, left front view.
1-2
TM 5-4320-258-34
Figure 1-2. Centrifugal pump, right rear view.
b. The centrifugal pump has a 6-inch suction
flange (7, fig. 5-1) secured to the front of the pump
body and a 6-inch discharge elbow secured to the top of
the pump body. The bearing housing (40, fig. 5-2)
joins the flywheel housing of the engine with the pump
body, providing correct spacing and proper alinement of
the parts. The bearing housing also provides the
bearing seats for the ball bearings that support the
impeller shaft. The impeller is keyed to the end of the
impeller shaft and is secured with nuts. The impeller is
enclosed in a close-fitting volute to provide efficient
pumping operation. A replaceable wear plate at the
front of the impeller takes most of the internal pump
wear.
c. The engine is a six-cylinder, water-cooled,
pressure-lubricated, four-stroke-cycle, L-head type.
Engine speed is governed by a flyball-type governor and
is protected by an overspeed governor that shuts off the
engine when the engine speed reaches the preset
speed. The engine is enclosed in a housing that has
coolant and oil drains ported to the outside of the
housing for easy access. The engine uses an electrical
starting motor, has magneto ignition, and uses an
alternator to maintain the charge of the battery which is
depleted by operation of the starting motor. The
conventional radiator-type cooling system uses a
pusher-type cooling fan which forces cooling air through
the radiator from the inside out. It also maintains a flow
of air around the engine to provide proper cooling.
1-5. Differences Between Models
This technical manual covers only the Barnes Model
US67CCG. No known changes exist in the equipment
procured under this model number.
1-3
TM 5-4320-258-34
Part number ........................MA24-900G
Voltage ..............................24
Amperage output.................35
(b) Voltage regulator.
Manufacturer.......................Motorola
Part number ........................70C44707B
(c) Starter.
Manufacturer.......................Delco-Remy
Part number ........................1108271
Voltage ...............................24
(d) Magneto.
Manufacturer.......................Slick
Model No. ...........................625
(e) Fuel pump.
Manufacturer.......................AC Spark Plug
Part number ........................5594228
(f) Air cleaner.
Manufacturer.......................Donaldson
Part number ........................FWG06-5032
(g) Oil filter.
Manufacturer.......................Fram
Part number ........................
C7407
(4) Overall dimensions and weight.
Overall length .....................111 in.
Overall width.......................31 in.
Overall height .....................55 in.
Overall weight .....................4000 lb
Shipping weight...................4270 lb
Shipping volume .................201 cu ft
(5) Engine torque specifications.
Item
Torque (ft-lb)
1-6.
Identification and Tabulated Data
a. Identification. The centrifugal pump has
three identification plates.
(1) US data plate. The US data plate is
located on front of the pump above the suction flange.
It indicates the pump identification number, serial
number, dimensions, weight, and shipping information.
(2) Engine plate. The engine data plate is
located on alternator side of the engine block. It
indicates engine identification numbers, serial number,
valve tappet clearance information, and patent
information.
(3) Instruction plate.
The pump
instruction plate is located in the cover of the control
panel. It identifies the controls and provides basic
operating instructions.
b. Tabulated Data.
(1) Pump.
Manufacturer.......................Barnes Manufacturing
Company
Part number ........................US67CCG
Serial number range............37628-001 thru 37628
047
Type....................................Centrifugal
Pumping medium................Petroleum products
Output (at maximum rated
speed) ...........................245 gpm at 205 feet
head 1120 gpm at 100
feet head
Maximum rated driven speed 2450 rpm
Suction port size .................6 in.
Discharge port size..............6 in.
(2) Engine.
Manufacturer.......................Continental Motors
Corporation
Model..................................
FS244-06097P
Type....................................
Four-stroke-cycle
Number of cylinders ............6
Displacement ......................244
Compression ratio ..............6.9:1
Cooling ...............................Liquid
Cooling system capacity......18 qts
Crankcase oil capacity ........5 qts
Valve clearance (warm)
Intake .............................0.014 in.
Exhaust ..........................0.016 in.
Spark plug gap....................0.025 in.
Breaker point gap................0.020 in.
Firing order .........................1-5-3-6-2-4
Governed speed..................2450 rpm
Overspeed cutout................2700 rpm
(3) Engine accessories.
(a) Alternator.
Manufacturer.......................Motorola
Cylinder head bolts .............
Main bearing cap bolts ........
Flywheel nuts ......................
Manifold nuts ......................
Gear cover bolts and nuts
5/16 in ...........................
3/8 in ..............................
Oil pan bolts........................
Flywheel housing bolts .......
Filler block bolts .................
Front end plate bolts ...........
Camshaft thrust plate bolts..
Water pump bolts ...............
Magneto bolts .....................
Governor bolts ....................
35-40
85-95
35-40
25-30
15-20
25-30
12-16
50-55
15-20
25-30
15-20
25-30
25-30
25-30
(6) Wiring diagram. See figure 1-3.
1-4
TM 5-4320-258-34
Figure 1-3. Wiring diagram.
1-5
TM 5-4320-258-34
CHAPTER 2
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
SECTION I. REPAIR PARTS, SPECIAL TOOLS, AND EQUIPMENT
the repair parts and special tools list covering direct
support and general support maintenance for this
centrifugal pump. Refer to TM 5-4320-258-35P (when
printed).
2-1. Special Tools and Equipment
No special tools and equipment are required for the
direct support and general support maintenance of the
centrifugal pump.
2-2. Maintenance Repair Parts
Repair parts and equipment are listed and illustrated in
SECTION II. TROUBLESHOOTING
the scope of operator/crew and organizational
2-3. General
maintenance, refer to TM 5-4320-258-12.
This section describes troubles which might occur during
2-4. Direct Support and General Support
operation of the centrifugal pump, along with the
probable causes and corrective actions relating to the
Maintenance Troubleshooting
troubles. Only those functions which are solely within
Refer to table 2-1 for troubleshooting which is allocated
the scope of direct and general support maintenance are
to direct support and general support maintenance
listed. For trouble shooting procedures which are within
levels.
Table 2-1. Troubleshooting
Malfunction
1. Engine will not crank.
Probable Cause
a. Impeller binding in volute.
b. Impeller bearings binding in
bearing housing.
c. Engine seized.
2. Engine cranks but will not start.
a. Carburetor defective.
b. Engine compression too low.
3. Water temperature safety switch
Stops engine operation.
a. Radiator clogged, causing engine
Overheating.
b. Cylinder head or block badly
scaled.
c. Safety switch improperly adjusted.
d. Water pump defective.
a. Oil pressure regulator valve imProperly adjusted.
b. Oil pump defective.
c. Safety switch improperly adjusted.
a. Overspeed governor not properly
adjusted.
b. Overspeed governor defective.
4. Oil pressure safety switch stops
engine operation.
5. Engine overspeed governor trips.
6. Engine lacks power, smokes, or
operates erratically.
a. Carburetor float level incorrect.
b. Carburetor defective.
2-1
Corrective Action
a. Disassemble pump and free
impeller (para 5-4).
b. Disassemble pump and replace
Bearings (para 5-4).
c. Remove engine (para 2-10).
Repair engine as necessary (para
4-3 through 4-13).
a. Repair carburetor (para 3-3).
b. Test engine to determine fault
(TM 5-4320-258-12). Repair
engine as necessary (para 4-3
through 4-13).
a. Clean radiator (para 3-7).
b. Clean cylinder head (Para 4-3) or
Block (para 4-13).
c. Adjust safety switch (para 3-9).
d. Repair water pump (para 3-8).
a. Adjust regulator valve (para 313).
b. Repair oil pump (para 4-7).
c. Adjust safety switch (para 3-12).
a. Adjusted overspeed governor (para
3-5).
b. Replace overspeed governor (para
3-5).
a. Adjust carburetor float level (para
3-3).
b. Repair carburetor (para 3-3).
TM 5-4320-258-34
Table 2-1. Troubleshooting-Continued
Malfunction
6. Engine lacks power, smokes or
operates erratically,-Continued
Probable Cause
c. One or more valves stuck open.
d. Valve springs weak.
e. Defective piston
7. Engine makes excessive noise
f. Piston rings worn.
g. Engine timing incorrect.
a. Main or connecting rod bearing.
Defective.
b. Flywheel rubbing on flywheel
housing
c. Loose pistons pins
d. Excessive crankshaft end play
e. Loose camshaft bearings.
8. Pump runs with no fluid discharge
or with low discharge.
9. Pump noisy.
f. Piston slap.
a. Impeller broken, worn, or
damaged.
b. Impeller-to-wear plate clearance
incorrect.
c. Wear plate excessively worn.
d. Shaft seal defective.
a. Impeller or wear plate loose.
b. Defective pump bearings.
Corrective Action
c. Free stuck valves; Replace or
regrind if burned (para 4-4).
d. Replace valve springs (para 4-4).
e. Replace defective piston (para 410).
f. Replace piston rings (para 4-10).
g. Correct engine timing (parp 4-12).
a. Replace defective bearing (para 410 and 4-11).
b. Aline flywheel housing (para 4-9).
c. Replace pistons (para 4-10).
d. correct crankshaft bearings (para
4-12).
e. Replace cramshaft bearings (para
4-12).
f. Replace worn pistons (para 4-10).
a. Replace impeller (para 5-4).
b. Add or remove shims as required
(par 5-4).
c. Replace wear plate (para 5-4).
d. Replace shaft seal (para 5-3).
a. Tighten impeller or wear plate
(para 5-4).
b. Replace pump bearings (para 5-4).
SECTION III. GENERAL MAINTENANCE
2-5.
General
This section contains general maintenance procedures
which are the responsibility of direct support and general
support maintenance personnel.
The paragraphs
contained herein describe general practices applicable
to several assemblies or components of the centrifugal
pump which would otherwise have to be repeated in
each section of the manual assigned to those
assemblies and components.
2-6.
Cleanliness
a. Take care to assure that the workplace is
clean before starting to disassemble the engine or pump
parts.
b. Steam-clean the exterior of the engine or
pump before starting disassembly to prevent the dirt
from entering the bearings. Clean the exterior of engine
components with a cloth dampened with cleaning
solvent (FED. Spec. P-D-680).
c. If compressed air is used to clean the parts,
make sure the compressed air is free from dirt and
contaminants.
d. Protect disassembled parts from blowing
sand and dust which could later cause rapid wear of the
gears, bearings, and machined surfaces.
2-7.
Care of Bearings
a. Clean ball and roller bearings by placing
them in a wire basket and immersing them into a
container of fresh cleaning solvent (FED. Spec. PD680). Agitate the bearings in the solvent to remove all
traces of old lubricant.
b. After the bearings are cleaned, dry them
with clean, filtered compressed air. Take care to
prevent spinning the bearings with the compressed air
jet.
c. Dip the cleaned bearings in clean engine
oil and immediately wrap them in lint-free paper to
prevent the entry of dust and dirt.
2-8.
Seals and Gaskets
Replace seals and gaskets of all components with each
disassembly. The use of new gaskets and seals will
greatly reduce the possibility of leaking and will help
prevent the entry of dust and dirt after reassembly.
2-2
TM 5-4320-258-34
SECTION IV. REMOVAL AND INSTALLATION OF MAJOR
COMPONENTS AND AUXILIARIES
2-9.
Centrifugal Pump,
Removal and installation. of :the centrifugal pump are
described in
2-10. Engine
a. Removal. Remove the engine from the
centrifugal pump as follows:
(1) Remove the. centrifugal pump (TM 54320-258-12).
(2) Disconnect the fuel lines connecting the
engine to the fuel tank.
Caution: Though, thisengineis equipped
with a reverse polarity protector to protect the
alternator'aigainst damage due to reverse-polarity
connectioi6ns, it is good practice to take special
precaut-ions, when connecting and disconnecting
electrical leads and cables. Do not ground the field
terminal between the iS alternator and regulator. Do
not operate the alternator in an open circuit with the
rotor winding energized. Do not ground the alternator output circuit. Take care to prevent reversing
polarity of the electrical system. When using a
battery booster or fast charger, make sure the leads
are connected with the correct polarity. Failure to
follow these in- structions may damage the
rectifiers, voltage regulator, and wiring.
(3) Disconnect the battery cables at the
battery, taking care to prevent shorting, grounding, or
reverse-polarizing the electrical system. Disconnect the
battery cable from the engine.
(4) Remove the nuts (1, fig. 2-1) and bevel
washers (2) that secure the lifting bail (4) to the skid
base (11); remove the lifting bail.
2-3
TM 5-4320-258-34
Figure 2-1. Engine removal.
(5) Remove the bolts (5 and 6), flat
washers (7), nuts (8), and lock washers (9) that secure
the engine to the skid base. Use a suitable lift truck to
lift the engine from the skid base, taking care to insert
the forks under structural members only.
b. Installation.
(1) Use a lift truck to position the engine on
the skid base (11). Take care to insert the forks under
structural members only. Secure the engine to the skid
base with bolts (5 and 6), nuts (8), lock washers (9), and
flat washers (7).
(2) Connect the battery cables to the
battery and to the engine. Review the caution in
subparagraph a above to prevent damage to the
components of the electrical system while connecting
the battery cables.
(3) Install the fuel lines connecting the
engine to the fuel tank.
(4) Position the lifting bail (4) on the skid
base; secure with nuts (1) and bevel washers (2).
(5) Install the centrifugal pump TM 5-4320258-12)
2-4
TM 5-4320-258-34
CHAPTER 3
REPAIR OF ENGINE COMPONENTS
SECTION I. REPAIR OF FUEL SYSTEM COMPONENTS
3-1.
Description of Fuel System
a. The fuel tank is bolted to the skid at the
radiator end of the engine. It is narrow enough to ride
between the longitudinal frame members of the skid. It
has an offset to permit part of the tank to slide under the
radiator end of the engine. The tank capacity is 30
gallons.
b. Fuel from the fuel tank is pumped to the
carburetor by a fuel pump mounted on and driven by the
engine. The updraft-type carburetor controls the fuel-air
mixture which is fed to the engine to meet the needs of
the engine power requirements. A float system controls
the level of the fuel in the carburetor float bowl.
Adjustment screws are provided to permit regulation of
the high-speed operation fuel mixture, the idle mixture,
and the idle speed. Choking is controlled manually.
c. Engine speed control is done by the
interoperation of the governor and the carburetor. The
governor is a variable-speed type and is driven by the
timing gear on the end of the camshaft. The driver on
the drive shaft of the centrifugal flyball governor
engages four hardened steel balls. As the engine runs,
centrifugal force tends to throw the balls outward. As
the engine speed increases, the centrifugal force
increases. This causes the balls to exert pressure
against a dished race, forcing the race to move , axially
away from the rotating balls. The movement of the
dished race is transferred to a drive fork through a thrust
bearing. The fork is pinned to the governing shaft which
pivots as the drive fork moves. An external governing
.lever on the end of the control shaft is connected to the
throttle control onthe carburetor and as the engine
speed tends to increase, the throttle is closed slightly,
resulting in a decrease in engine speed. The decrease
in engine speed decreases the centrifugal force of the
balls, and the dished race moves axially toward the
balls. This movement is sensed by the fork which, in
turn, transfers the movement to the external governing
lever.
The governing lever opens the carburetor
throttle, tending to speed up the engine. In this manner,
a balanced condition is reached and the engine speed
remains constant, keeping the engine speed at the level
determined by the throttle control setting. Adjustment of
the governor'is made by changing the tension of the
spring which applies tension to the external governing
lever and which tends to keep the dished race against
the flyballs. Tightening the spring tends to raise engine
speed at any particular throttle control setting.
Decreasing spring tension lowers the speed.
3-1
TM 5-4320-258-34
Figure 3-1. Operation of engine speed regulating system.
d. The engine is protected from overspeeds
by the overspeed governor (fig. 3-6). The overspeed
governor is mounted on an adapter on the top center of
the cylinder head. It is driven by a shaft which engages
the top of the oil pump drive shaft which is, in turn,
driven by a geared portion of the camshaft. The
overspeed governor is adjusted to stop the engine if
crankshaft speed exceeds 2700 rpm. The stopping is
accomplished by grounding the magneto primary
through a switch which closes in the governor
mechanism. A reset button at the top of the overspeed
governor must be 'pressed to reset the switch if the unit
it tripped by an overspeed condition.
3-2.
Fuel Tank
a. Removal and Disassembly.
(1) Disconnect the fuel lines and fittings
from the fuel tank (TM 5-4320-258-12)
(2) Remove the battery box from the skid
base.
(3) Remove the drain plug (1, fig. 3-2)
from the bottom of the fuel tank and catch the fuel in a
suitable container.
KEY to fig. 3-2:
1. Drain plug
2. Cap screw
3. Lock washer
4. Fuel tank cap
5. Chain
6. Screen
7. Nut
8. Lock washer
9. Fill plate
10. Gasket
11. Suction pipe
12. Pipe plug
13. Nut 1
14. Autofill float valve
15. Fuel level gage
16. Fuel tank
3-2
TM 5-4320-258-34
Figure 3-2. Fuel tank, exploded view.
3-3
TM 5-4320-258-34
brackets, cracked seams, loose studs, and damaged
threads. Replace a damaged fuel tank.
(3) Inspect the autofill float valve (14, fig.
32) for binding or catching operation of the float valve.
Inspect the float valve seat for nicks and damage.
Replace a damaged float valve.
(4) Inspect the fuel level gage for free
operation of the float valve and proper registration of the
level indicator. Replace if damaged.
c. Installation.
Install the fuel tank by
reversing the removal procedure. Refer to figure 3-2.
3-3.
Carburetor
a. Removal. Remove the carburetor (TM
54320-258-12).
b. Disassembly. Disassemble the carburetor
as shown in figure 3-3. The index numbers assigned to
the parts indicate the order of disassembly. Note the
following:
(4) Remove the four bolts and lock washers
that secure the fuel tank to the skid 'base. Remove the
fuel tank.
(5) Disassemble the fuel tank as shown in
figure 3-2.
b. Cleaning and Inspection.
(1) Steam-clean the inside and outside of
the fuel tank. Thoroughly flush with cleaning solvent
(FED. Spec. P-D-680).
Warning: If conditions require emergency
fuel tank repairs by welding or other methods
involving heat or flame, take care to assure that all
gasoline fumes are purged from the tank before
commencing the repair. Applying heat or flame to a
fuel tank containing gasoline residue may result in a
violent explosion, causing injury or death to
maintenance personnel.
(2) Inspect the fuel tank for loose mounting
34. Pump piston
35. Idling jet
36. Throttle body
37. Shaft nut
38. Lock washer
39. Return spring
40. Swivel screw
41. Air shutter lever
42. Clamp screw
43. Nut
44. Wire clamp
45. Shaft bushing
46. Air shutter bracket
47. Screw 48. Shutter plate
49. Air shutter shaft
50. Shaft hole plug
51. Fiber washer
52. Main jet adjusting
53. Fiber washer
54. Main jet
55. Fiber washer
56. Lower plug
57. Fiber washer
58. Accelerator jet
59. Fiber washer
60. Main discharge jet
61. Fiber washer
62. Power jet valve
63. Well vent
64. Check valve
65. Pipe plug
66. Drip plug
67. Fuel bowl assembly
KEY to fig. 3-3:
1. Screw
2. Gasket
3. Float axle
4. Float and hinge assembly
5. Fuel valve
6. Fuel valve seat
7. Fiber washer
8. Filter head
9. Washer
10. Filter element
11. Idle adjusting screw
12. Spring
13. Venturi screw
14. Venturi
15. Cotter pin
16. Retainer
17. Clamp screw
18. Clamp lever
19. Spring
20. Bushing
21. Stop screw
22. Clamp screw
23. Nut
24. Lever stop
25. Swivel screw
26. Floating lever
27. Taper pin
28. Throttle plate screw
29. Throttle plate
30. Throttle shaft
31. Shaft hole plug
32. Seal retainer
33. Shaft seal
3-4
TM 5-4320-258-34
Figure 3-3. Carburetor, exploded view.
3-5
TM 5-4320-258-34
(1) To remove the float axle (3), press a
screwdriver against the float axle at the slotted side of
the float hinge bracket. Remove the axle from the
opposite side and remove the float (4).
(2) After the float is removed, take care
that the fuel valve (5) does not drop from the valve seat
(6).
(3) Use a file to match-mark the throttle
lever (on the throttle shaft (30)) and the throttle body
(36). These marks will serve as a guide to assure that
the parts will be reassembled in the proper manner.
(4) Use a file to match-mark the air shutter
bracket (46), air shutter lever (41), and the boss on the
fuel bowl (67). These marks will serve as a guide to
assure proper reassembly.
(5) To remove the plug (31), insert a 1/4inch rod, 6 inches long, through the opposite side of the
throttle body (36) and drive out the shaft hole plug (31).
c. Cleaning and Inspection.
(1) Clean all parts in an approved
carburetor cleaner. Wash with cleaning solvent (FED.
Spec. P-D-680). Dry thoroughly with compressed air.
Caution: Do not clean by inserting a wire or drill into any
openings or passages as this will destroy their fine
calibration.
(2) Blow out all passages in the air intake,
fuel bowl, and throttle body with compressed air. (3)
Inspect the float for cracks, worn float axle bearing,
wear in the needle valve contact area, and other visible
damage. Replace the float if it is damaged or if it is
loaded with gasoline.
(4) Inspect the float axle for wear on the
bearing surface. Replace if any wear can be
detected.
(5) Inspect the needle valve and needle
valve seat for wear or damage. Both parts must be
replaced as an assembly if either is damaged.
(6) Inspect the idle adjusting screw for
damaged threads and for a worn needle point. The
point must be sharp and free from ridges of the tapered
area.
(7) Inspect the throttle plate for burrs or
damaged edges. Clean with crocus cloth to remove
light burrs. Do not use a buffing wheel on the throttle
plate. Replace if edges are damaged.
(8) Inspect the throttle shaft for wear of the
bearing areas. Replace the shaft if visible wear is
noted.
(9) Inspect the pump lever for distortion
and for wear of the pump link hole. Replace if
damaged.
(10) Inspect the air shutter plate for
distortion, burrs, and damaged edges. Make sure the
poppet valve on the choke plate is free. Replace a
damaged choke plate.
(11) Inspect the air shutter shaft for cracks,
distortion, and for worn bearing surfaces. Replace if
damaged.
(12) Inspect the fuel bowl assembly and
throttle body for cracks, distortion, damaged threads,
and other damage. Inspect the bearing surfaces of the
throttle shaft and air shutter shaft bores for wear or
scoring. Replace damaged housings.
(13) Inspect all other parts for cracks,
distortion, and other damage; replace damaged parts.
d. Reassembly.
Refer to figure 3-3 to
reassemble the carburetor. Reassembly is the reverse
of disassembly. Note the following:
(1) During reassembly, aline the match
marks made during disassembly on the fuel bowl (67),
air shutter bracket (46), air shutter shaft (49), and lever
(41).
(2) Aline the match marks made at
disassembly on the throttle body (36) and lever of the
throttle shaft (30).
(3) Note that the screw holes in the throttle
plate (29) are off-centered. Start the side of the throttle
plate with the shortest distance between the screw holes
and beveled edge into place first. The plates are made
with two opposite edges beveled to fit the throttle body
bore when the plate is closed. The throttle plate will not
close tightly if installed upside down. Pressure on the
plate must be maintained with the finger until the screws
are tightened. When properly installed, the side of the
throttle plate farthest away from the mounting flange will
be alined with the idle discharge holes when the plate is
closed.
e. Installation.
Install and adjust the
carburetor (TM 5-4320-258-12).
3-4.
Governor
a. Removal. Remove the governor from the
engine (TM 5-4320-258-12).
b. Disassembly. Disassemble the governor,
following the sequence of numbers assigned to figure 34. Note the following
3-6
TM 5-4320-258-34
1. Screw
2. Retaining ring
3. Retaining ring washer
4. Ball stop washer
5. Fork base
6. Thrust bearing
7. Upper race
8. Ball
9. Drive gear
10. Governor base
11. Ball bearing
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
Lower race spacer
Lower race
Drive shaft
Driver
Adjusting screw
Lock nut
Plug
Groove pin
Fork
Bumper Spring
Spring pin
Figure 3-4. Governor, exploded view.
3-7
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
Governing lever
Governing shaft
Expansion plug
Gasket
Oil seal
Needle bearing
Bushing
Thrust washer
Drive screw
Name plate
Governor housing
TM 5-4320-258-34
(7) Inspect the balls (8)-for scoring, nicks,
and other damage; replace damaged balls.
(8) Inspect the drive gear (9) for damaged
gear teeth, worn or scored internal diameter, and
damaged drive notches; replace a damaged drive gear.
(9) Inspect the fork and bumper spring (21)
for wear and distortion. Replace damaged parts.
(10) Inspect the governing shaft (24) and
lever (23) for wear and distortion; replace damaged
parts. (11) Inspect the governor housing (33) for cracks,
damaged bores, distorted mounting flange, and other
damage; replace a damaged body.
d. Reassembly. Reassemble the governor as
shown in figure 3-4. Note the following:
(1) Lubricate all operating parts with clean
engine oil during reassembly.
(2) If the bushing (29) was removed from
the bushing seat in the governor housing, place the
thrust washer (30) in the seat and press the bushing
squarely into the seat, taking care not to damage the
bushing end. Press it in until it is firmly seated against
the thrust washer.
(3) When pressing the drive gear (9) onto
the end of the drive shaft (14), lubricate the end of the
shaft with engine oil and press the gear squarely onto
the shaft. Take care to support the opposite end of the
shaft in a manner which will prevent peening or burring
the shaft end.
(4) After installing the retaining ring (2), pull
the retaining ring washer (3) over the retaining ring to
lock it in place.
(5) After reassembly, rotate the governor
shaft. It must turn freely without binding, scraping, or
catching.
e. Installation. Install and adjust the governor
on the engine (TM 5-4320-258-12).
3-5.
Engine Overspeed Governor
a. Testing and Adjustment. The engine overspeed governor must shut off the engine when engine
speed reaches or exceeds 2700 rpm. Test and adjust
as follows:
(1) Start the. engine and allow it to warm
to operating temperature, then shut it off.
(2) Disconnect the linkage from the engine
speed governor (TM 5-4320-258-12) so that the engine
speed can be controlled by manually manipulating the
carburetor throttle lever. Caution: Do not operate the
engine at speeds greater than 2750 rpm. Engine overspeed can result in severe engine damage.
(3) Restart the engine and have an
assistant watch the tachometer. Slowly increase engine
speed with no load until the engine stops as the result of
the operation of the overspeed governor or until the
tachometer indicates 2750 rpm.
(1) Remove the screw (1) to release the
governor drive shaft assembly (items 2 through 15) from
the governor housing (33).
(2) Slide the retaining ring washer (3)
toward the upper race (7) on the drive shaft to expose
the retaining ring (2). Remove the retaining ring and
slide the washer (3), ball stop washer (4), fork base (5),
thrust bearing (6), and upper race (7) from the drive
shaft assembly. This will release the four balls (8).
(3) -Support the drive gear (9) in a press
and press the drive shaft (14) from the gear. Remove
the governor base (10) with the assembled bearing (11),
lower race spacer (12), and the lower race (13) from the
shaft.
(4) Press the ball bearing (11) from the
governor base (10).
(5) Do not attempt to press the driver (15)
from the drive shaft (14) unless either of the parts is
damaged.
(6) Drive out the groove pin (19) that
secures the fork (20) to the governing shaft (24). Pull
the assembled governing lever (23) and shaft (24) from
the governor housing (33) to release the fork. Remove
the fork.
(7) Pierce the expansion plug (25) and pry
it from the governor housing (33) along with the gasket
(26).
(8) Insert a soft drift through the needle
bearing (28) on the expansion plug side of the housing,
and drive out the oil seal (27) and the needle bearing
(28) from the housing. Insert the drift from the opposite
side and drive out the remaining needle bearing.
(9) If the bushing (29) is damaged, thread it
with a tap of suitable size and turn a bolt into the
threaded bore. Pull the assembled bolt and bushing
from the housing (33).
c. Cleaning and Inspection.
(1) Clean the bearings as directed in
paragraph 2-7.
(2)'Clean all remaining parts by washing in
cleaning solvent (FED. Spec. P-D-680); dry thoroughly.
(3) Inspect the bearings for rough, catching,
or binding operation. Check the balls or rollers for
scoring and check the races for damage. Replace
damaged bearings.
(4). Inspect the upper race (7) and the
lower race (13) for scoring, cracks, and distortion.
Check the internal diameter of the bores for an out-ofround condition. Replace damaged races.
(5) Inspect the driver for scoring, cracks,
wear in the ball pockets, and other damage; replace a
damaged driver.
(6) Inspect the drive shaft for misalinement
and for wear at the bushing end. Replace a damaged
shaft.
3-8
TM 5-4320-258-34
(4) If the engine did not shut off as the
result of the tripping of the overspeed governor, the
overspeed governor requires adjustment. If the engine
stopped before the tachometer indicated 2650 rpm, the
engine overspeed governor must be adjusted.
(5) To adjust the engine overspeed
governor, loosen the lock screw (3, fig. 3-5) that
secures the cap (2) in position. To decrease the engine
shutoff speed, rotate the cap clockwise. To raise the
engine shutoff speed, turn the cap counterclockwise.
Tighten the lock screw.
1. Reset button
2. Cap
3. Lock screw
Figure 3-5. Engine overspeed governor, showing
adjusting points.
(6) Recheck the speed at which the
overspeed governor stops the engine as directed in
steps (1) through (3) above. Readjust until the engine
shuts off at 2700 rpm. Replace the engine overspeed
governor if it cannot be adjusted.
(7) Reconnect the engine speed governor.
b. Removal.
(1) Remove the tachometer drive from the
governor arm (TM 5-4320-258-12)
(2) Disconnect the electrical leads from the
terminals at the top of engine overspeed governor. Tag
leads to facilitate reassembly.
(3) Remove and disassemble the
overspeed governor and related parts as shown in figure
3-6.
1. Cap screw
2. Lock washer
3. Overspeed governor
4. Cap screw
5. Lock washer
6. Governor arm
7. Nut
8. Lock washer
9. Cap screw
10. Adapter
11. Governor drive shaft
Figure 3-6. Engine overspeed governor and related
parts, exploded view.
c. Cleaning and Inspection.
(1) Wipe the exterior of the engine
overspeed governor with a cloth dampened with
cleaning solvent (FED. Spec. P-D-680); dry thoroughly.
Take care to prevent solvent from entering the interior
of the unit.
(2) Wash all remaining parts with cleaning
solvent (FED. Spec. P-D-680). Remove the grease
3-9
TM 5-4320-258-34
cup from the governor arm and carefully remove all
grease from the cup and from the interior of the arm.
(3) Remove all grease from the toothed
portion of the governor drive shaft. Use a soft- bristled
brush, if necessary, to remove the grease.
(4) Inspect the engine overspeed governor
for cracks, loose or damaged terminals, and damaged
coupling at the end of the shaft. Rotate the shaft to
check for rough, catching, or binding operation.
Replace a damaged overspeed governor.
(5) Inspect the governor drive shaft for
cracks, damaged teeth, distortion and other damage;
replace a damaged drive shaft.
(6) Inspect all other parts for cracks,
distortion, damaged threads, and other damage; replace
damaged parts.
d. Reassembly and Installation.
(1) Reassemble and install the engine
overspeed governor and related parts as shown 'in
figure 3-6.
(2) Reconnect the electrical leads to the
terminals at the top of the overspeed governor.
(3) Reconnect the tachometer drive and
tachometer shaft to the governor arm, and lubricate the
tachometer drive and overspeed governor (TM 5-4320258-12).
(4) Check and, if necessary, adjust the
engine overspeed governor (subparagraph a above).
SECTION II. REPAIR OF COOLING SYSTEM COMPONENTS
3-6.
Description of Cooling System
a. Liquid coolant is pumped around the
cylinder walls and valve guides in the cylinder block and
around the tops of the cylinders in the cylinder head to
remove the heat of combustion from the engine. This is
necessary to prevent the excessive heat from damaging
the engine.
b. As the hot coolant is pumped from the
engine, it enters the radiator consisting of tubes and fins
which dissipate the heat to the atmosphere. The fluid
passes into the top of the radiator and out through the
bottom. The cooling fan maintains a blast of air through
the radiator to help dissipate the heat.
c. The coolant from the radiator enters the
water pump which is V-belt driven by the engine to
circulate the coolant through the block and cylinder head
to complete the cycle. The centrifugal water pump is
mounted on the cylinder block.
d. The engine is protected from overheating
by coolant temperature safety switch (2, fig. 3-7)
mounted on the control panel. This switch closes a set
of contacts to stop the engine by grounding the magneto
primary before engine coolant tem- perature reaches the
point that engine damage can occur. The switch trip
point is adjustable.
1.
2.
3.
4.
5.
Oil pressure safety switch
Coolant temperature safety switch
Temperature switch adjusting screw
Oil pressure switch adjusting screw
Oil safety switch pushbutton
Figure 3-7. Coolant temperature and oil pressure safety
switches.
3-10
TM 5-4320-258-34
the radiator in a tank of water and apply 10 psi air
pressure to the interior of the radiator. Check for air
bubbles that could indicate a leak. If a leak is found,
mark the area for repair.
(3) Inspect all hardware for cracks and for
worn or stripped threads.
(4) Replace all parts damaged beyond
repair.
d. Repair.
(1) Repair leaks by soldering. Be sure that
the repair does not block or retard circulation through
any tubes. There shall be no blocked tubes.
(2) Straighten any bent or damaged fins.
Replace any damaged parts.
e. Installation. Install the radiator (TM 5-4320258-12).
3-8.
Water Pump
a. Removal. Remove the water pump from
the engine (TM 5-4320-258-12).
b. Disassembly.
(1) Disassemble the water pump only if the
shaft binds, the seal leaks, the housing is cracked or
damaged, or there are other signs of faulty operation.
(2) Use a puller to pull the drive pulley (2,
fig. 3-8) from the water pump
3-7.
Radiator
a. Removal. Remove the radiator (TM 54320- 258-12).
b. Cleaning.
(1) Clean the exterior of the radiator by
flushing in a reverse-flow direction with stream of water
to remove all bugs and debris. Remove any greasy or
oily deposits with cleaning solvent (FED. Spec. P-D680).
(2) Reverse-flush the interior of the
radiator, using a flushing gun.
c. Inspection and Testing.
(1) Inspect all parts for cracks, signs of
leaking tubes or gaskets, damaged thread's, or other
obvious damage.
Caution: Do not exceed 10 psi air pressure
for radiator testing. Excess pressure will damage
the radiator.
Be sure' the radiator core is
completely drained before testing. When testing at
low pressure, it is possible that water within the
core could prevent air from passing out of small
holes, and the leak could pass undetected.
(2) Make sure the radiator is completely
drained of coolant. Plug all openings, except one
through which compressed air can be applied. Immerse
3-11
TM 5-4320-258-34
Figure 3-8. Water pump, exploded view
3-12
TM 5-4320-258-34
d.
(3) Use a puller to remove the impeller (6)
from the shaft, taking care to prevent damage to the
casting.
(4) To remove. the water pump shaft (10)
from the housing (12), remove the retaining ring (9) and
press on the impeller end of the shaft to press the shaft
out of the fan end of the housing. Pressing the fan out
in the opposite direction will severely damage the
housing.
c. Cleaning and Inspection.
(1) Discard and replace seals, gaskets, and
all parts contained in the water pump repair' kit. Clean
all remaining parts with cleaning solvent (FED. Spec.
P-D-680); dry thoroughly.
(2) Inspect the water pump housing for,
cracks, distortion, and scoring of the seal contact
surface. Replace the entire water pump if housing is
dam- aged. (3) Inspect all other parts for cracks, worn
or damaged threads, distortion, and other damage;
replace damaged parts.
Reassembly.
(1) Reassemble the water pump as shown
in figure 3-8.
(2) Apply a light film of grease to the face
of the seal to facilitate sealing and seating.
(3) When assembling the seal and shaft,
apply a thick coating of soap suds to the parts to prevent
damage to the seal.
e. Installation. Install the water pump on the
engine (TM 5-4320-258-12).
3-9.
Coolant Temperature Safety Switch
a. Removal.
(1) Disconnect the electrical leads from the
coolant temperature switch. Tag leads to facilitate
reassembly.
(2) Disconnect the coolant temperature
safety switch sender from the engine.
(3) Remove the coolant temperature safety
switch from the control panel (see items 1 through 4, fig.
3-9).
Figure 3-9.Coolant temperature and oil pressure safety switches, exploded view.
3-13
TM 5-4320-258-34
b.
Cleaning and Inspection.
(1) Wipe the coolant temperature safety
switch with a cloth dampened with cleaning solvent
(FED. Spec. P-D-680); dry thoroughly.
(2) Inspect the coolant temperature safety
switch for broken, loose, or corroded terminals, severe
dents, and other obvious damage. Check and adjust the
switch as directed in subparagraph c below.
c. Testing and Adjustment.
(1) Suspend the sender of the coolant
temperature safety switch and a thermometer in a
container so that neither the sender nor the thermometer
touches the sides or bottom of the container. Connect a
multimeter, set to read continuity, across the terminals
of the switch. No continuity should be indicated at
normal temperatures.
(2) Heat the container while watching the
thermometer and the multimeter.
As the water
temperature reaches approximately 2100F, the
multimeter should indicate continuity through the switch.
(3) If the switch remains open, or closes at
too low a temperature, loosen the lock nut on the
adjusting screw (3, fig. 3-7) and adjust the switch so
that it just closes at 2100F. Lock the lock nut to secure
the adjustment.
d. Installation. Installation is the reverse of
removal. Refer to items I through 4 in figure 3-9. If
necessary, refer to the wiring diagram, figure 1-3, for
wiring connection information.
SECTION III. REPAIR OF OIL SYSTEM COMPONENTS
c. The engine is protected from a low oil
pressure condition by an oil pressure safety switch (1,
fig. 3- 7) mounted on the engine control panel. This
switch is adjustable and provides a reset push- button to
reset the device for starting.
3-11. Engine Oil Filter
a. Removal.
(1) Drain the oil from the engine (TM 54320-258-12).
(2) Disconnect the electrical lead from the
oil pressure sender on the filter piping.
(3) Remove the oil filter and related parts
from the engine as shown in figure 3-10
3-10.
Description of Engine Oil System
a. The engine oil system provides lubrication
for the working surfaces within the engine. The oil is
retained in the oil pan under the engine and is circulated
through the engine by the oil pump mounted on one of
the main bearing caps of the engine.
Internal
components of the engine lubrication system are
covered in chapter 4, which describes basic engine
overhaul. Oil pressure ad- justment is described in
paragraph 3-13.
b. An oil filter with its related piping is
mounted on the exterior of the engine to remove from
the engine oil impurities and particles that could cause
engine wear.
This filter has a replaceable-type
cartridge.
3-14
TM 5-4320-258-34
Figure 3-10. Engine oil filter mounting, exploded view.
3-15
TM 5-4320-258-34
Blow through the hose with compressed air to make
sure it is not clogged.
(3) Inspect the, :oil pressure safety switch
for cracks, dents, damaged threads, and loose or
corroded electrical terminals; replace if damaged.
(4) Inspect the hose for abrasions,
deterioration, and damaged threads; replace a damaged
hose.
(5) Inspect the remaining parts for cracks,
damaged threads, distortion, and other damage; replace
damaged parts.
c. Adjustment and Testing.
(1) Connect the pressure inlet of the oil
pressure safety switch/ to an adjustable and calibrated
air pressure source. Connect a multimeter, adjusted
to read continuity, across the electrical terminals.
(2) Under a no-pressure condition, press
and release the oil safety switch pushbutton (5, fig. 3-7)
while watching the multimeter. It must indicate no
continuity after the safety switch pushbutton is pressed.
(3) With the safety switch pushbutton re- leased,
slowly apply pressure to the oil pressure safety switch
while watching the multimeter. Continue to increase
pressure to approximately 60 psi and then slowly
decrease pressure while noting the indication of the
multimeter. As pressure is decreased to between 5 and
6 psi, continuity must be made through the switch.
Continuity must be broken as the oil pressure safety
switch pushbutton is pressed.
(4) If the switch fails to close between 5
and 6 psi, turn the adjusting screw (4, fig. 3-7) on the
switch to adjust the switch closing to the required level.
(5) Recheck the adjustment and, if
necessary, repeat until the proper closing point is
attained.
d. Installation. Installation of the oil pressure
safety switch is the reverse of removal. Refer to items 6
through 11 of figure 3-9. If necessary, refer to the wiring
diagram (fig. 1-3) for wire connection information.
3-13. Engine Oil Pressure Adjustment
a. Description. The engine oil pressure is
regulated by a relief valve mounted in the engine
cylinder block. It consists mainly of a spring- loaded,
spool-type valve which seats in a bore in the block. The
greater the spring pressure which loads the valve, the
greater is the oil pressure in the system. The pressure
is increased by adding pressure-adjusting washers
between the spring and the valve to increase spring
force against the valve.
b. Adjustment.
(1) Start the engine and allow it to warm to
operating temperature. Check the engine oil pressure
indicated on the oil pressure gage. At idle speed, the
pressure must exceed 7 psi; at governed speed it must
be between 20 and 30 psi.
(2) If the engine oil pressure is not within
the required range, shut off the engine and remove the
plug (23, fig. 4-22) from the carburetor side of the
engine block. Remove the relieve valve spring (25) and
pressure adjusting washers (26).
(3) To increase oil pressure, add a washer
between the spring and valve. Not more than four
washers are allowed. If four washers fail to bring it into
the required range, the spring is faulty or other engine
troubles exist.
(4) After adjustment, check that the oil
pressure remains in the required ranges during
operation.
SECTION IV. REPAIR OF ENGINE MOUNTING
(1) Remove the engine from the centrifugal
pump assembly (para 2-10).
(2) Remove the engine housing from the
engine (TM 5-4320-258-12).
(3) Remove the radiator (TM 5-4320-258-12).
(4) Support the engine with a hoist engaged
in the lifting eye at the top of the engine.
(5) Remove the tie rods and related parts
(items 1 through 9, fig. 3-12) that connect the radiator
support (23) with the flywheel housing
3-14. Description
The engine is mounted on the radiator support assembly
at the front, and on the feet of the flywheel housing at
the rear. The resilient support at the front of the engine
helps cushion the engine vibration, preventing it from
being transmitted to the associated equipment. The
radiator support is connected to the flywheel housing by
adjustable tie rods.
3-15. Engine Support
a. Removal.
3-17
TM 5-4320-258-34
Figure 3-12. Engine mounting parts, exploded view
3-18 cracks, deterioration, loss of resiliency, cuts, and
other damage; replace the mounting parts if damaged.
(3) Inspect the support tie rod and the stud
for damaged threads and distortion; replace damaged
parts.
(4) Inspect the radiator support for cracks,
broken weldments, distortion, and other damage;
reweld, straighten, or replace a damaged support.
(5) Inspect the ground strap for rust,
corrosion, and other damage. If necessary, sand- paper
the end terminals to assure a good electrical contact
between the radiator support and engine at installation.
c. Installation.
(1) Install the engine on the radiator
support
Caution: Do not rest the engine on its oil
pan. This may damage the oil pan.
(6) Remove the cotter pin (10), nut (11),
flat washer (12), and support mounting (13) from the
end of the gear cover stud (19). Raise the engine out of
engagement with the radiator support. Mount the
engine on an overhaul stand or provide proper blocking
to rest it on the floor.
(7) Remove the flat washer (20), support
mount (21), and mount retainer (22) from the radiator
support.
b. Cleaning and Inspection.
(1) Clean the rubber mounting parts with a
cloth dampened with cleaning solvent (FED. Spec. PD-680). Wash all remaining parts in solvent.
(2) Inspect the rubber mounting parts for
3-18
TM 5-4320-258-34
horizontal when the tie rods are installed..
(3) Install the radiator (TM 5-4320-258-12).
(4) Install the engine housing (TM 5-4320258-12).
(5) Install the engine on the centrifugal
pump assembly (para 2-10).
as shown in figure 3-12. Make sure the ground strap
(18) is making good electrical contact between parts.
(2) When installing the tie rods (9) that
connect the radiator support with the flywheel housing,
position the inner nuts so that they prevent excessive
strain on the radiator support when the outer nuts are
tightened. The bottom of the radiator support must be
3-19
TM 5-4320-258-34
CHAPTER 4
BASIC ENGINE OVERHAUL
SECTION I. INTRODUCTION AND FITS, TOLERANCES,
AND WEAR LIMITS
Paragraph 4-2 provides the fits, tolerances, and
allowable wear limits which are useful in determining if
parts replacement is necessary.
4-1.
Introduction
This chapter provides instructions relating to engine
repair and overhaul. It includes information regarding
disassembly, inspection of parts to determine if their
continued serviceability is possible or if they should be
replaced, instructions covering repair techniques such
as valve grinding and cylinder honing, reassembly and
tolerance checking to assure proper fits and clearances,
and all other information relating to engine overhaul.
4-2. Fits, Tolerances, and Wear Limits
Table 4-1 lists the fits and tolerances applicable to the
engine.
Refer to the table to determine if parts
replacement is required or if containued serviceability of
the parts is possible.
4-1
TM 5-4320-258-34
Table 4-1. Engine Fits, Tolerances, and Wear Limits
Component points of measurement
Valve and valve guides
Intake valves
Cylinder block face-to-guide distance
Outside diameter
Inside diameter
Valve stem diameter
Stem-to-guide clearance
Valve tappet clearance
Exhaust valves
Cylinder block face-to-guide distance
Outside diameter
Inside diameter
Valve stem diameter
Stem-to-guide clearance
Valve tappet clearance
Valve tappets
Outside diameter
Tappet bore diameter
Maximum bore-to-tappet clearance
Camshaft and bushings
Bearing journal diameter
No. 1
No. 2
No. 3
No. 4
Camshaft bushing diameter
No. 1
No. 2
No. 3
No. 4
Journal-to-bushing clearance
No. 1
No. 2
No. 3
No. 4
Camshaft end play
Connecting rod
Bushing hole diameter
Bearing hole diameter
Side play
Connecting rod bearing
Bearing hole diameter
Bearing thickness
Crankpin diameter
Bearing to crankshaft clearance
Crankshaft
End thrust
Main bearing journal diameter
Crankpin diameter
Main bearings
Case hole
Bearing thickness
Crankshaft journal diameter
Journal-to-bearing clearance
Piston
Ring groove width
1st
2nd and 3rd
4th
Cylinder bore diameter
Piston fit in bore. Check by pull on 1/ 3-inch
wide-0.003-inch feeler gage
Manufacturer's
and tolerances
Minimum
dimensions
in inches
Maximum,
Design
in
Minimum
clearances
inches
Maximum
Allowable
wear or
clearance
115/32
0.6565
0.3422
0.3406
0.6575
0.3432
0.3414
0.0008
0.0026
0.3447
0.3386
0.0046
0.0140
115/32
0.6565
0.3422
0.3377
0.6575
0.3432
0.3385
0.0037
0.0055
0.3447
0.3357
0.0075
0.0160 (Hot)
0.0170 (Cold}
0.9990
1.0000
0.0050
1.8715
1.8085
1.7457
1.2465
1.8725
1.8095
1.7465
1.2475
1.8745
1.8115
1.7495
1.2495
1.8755
1.8125
1.7502
1.2505
0.9130
2.1865
1.8705
1.8075
1.7447
1.2455
0.0020
0.0020
0.0020
0.0020
0.0050
0.0040
0.0040
0.0040
0.0040
0.0090
0/0060
0.0100
0.9140
2.1870
2.1865
0.0613
2.0619
2.1870
0.0616
2.0627
2.3744
2.0619
2.3752
2.0627
2.3734
2.0609
2.5615
0.0925
2.3744
2.5622
0.0928
2.3752
0.0920
2.3734
0.0608
2.0609
0.0032
0.0030
0.0007
0.1270
0.1275
0.2520
3.4375
0.1290
0.1285
0.2530
3.4395
4-2
0.0080
0.0028
0.1305
0.1305
0.2550
3.4475
5-10 lb
TM 5-4320-258-34
Component points of measurement
Piston rings
Width
No. 1
No. 2 and 3
No. 4
Gap
No. 1
No. 2 and 3
No. 4
Side clearance
No. 1
No. 2 and 3
No. 4
Piston pin
Length
Pin diameter
Piston pin bushing diameter
Piston pin fit in piston
Piston pin fit in rod
Valve spring (intake and exhaust)
Weight required to compress to 1
45/64 in.
Weight required to compress to 1
27/64 in.
Manufacturer
's
and
tolerances
Minimum
dimensio
ns
in inches
0.1230
0.1235
0.2485
0.1240
0.1240
0.2490
2.8050
0.8591
0.8595
Maximu
m,
Design
in
Minimu
m
clearanc
es
inches
Allowable
Maximu
m
clearance
0.1210
0.1215
0.2465
0.0070
0.0070
0.0070
0.0170
0.0170
0.0170
0.0035
0.0035
0.0030
0.0050
0.0055
0.0045
2.8150
0.8593
0.8597
0.8607
0.8067
Light
0.0002
4-3
wear or
Push
0.0006
47 lb
53 lb
42 lb
96 lb
104 lb
86 lb
TM 5-4320-258-34
SECTION II. ENGINE OVERHAUL
Note. Some engine repair can be done with the
engine in the engine housing. More extensive repair will
require removal of the engine from the housing. Major
repair or overhaul requires that the engine be mounted
on an engine overhaul stand. Remove the engine
housing (TM 5-4320-258-12). Remove the engine from
its mounting parts if necessary (para 3-15). Remove
accessories from the engine as required. Refer to TM
5-4320-258-12.
4-3.
Cylinder Head
a. Removal. Remove the cylinder head and
gasket as shown in figure 4-1.
4-4
TM 5-4320-258-34
Figure 4-1. Cylinder head, exploded view.
4-5
TM 5-4320-258-34
gradually decreasing toward the ends. Check flatness
lengthwise at each edge and in the middle of the head.
(5) Check flatness crosswise with a
straightedge and a feeler gage.
The maximum
permissible low spot is 0.003 inch in localized areas.
Check flatness crosswise at each end and between each
combustion chamber.
(6) Inspect cylinder head studs for
looseness or damaged threads.
(7) Replace the gasket, hoses, and
defective parts.
c. Installation. Using a new head gasket,
install head in reverse order of removal. Tighten the
cylinder head screws in the sequence shown in figure 42. Torque to 35 to 40 foot-pounds.
b.
Cleaning and Inspection.
(1) Remove all carbon from combustion
areas with a scraper and wire brush.
Clean all
remaining residue from the cylinder head with cleaning
solvent (FED. Spec. P-D-680). Dry with clean, dry
compressed air.
(2) Clean the top of the cylinder block with
a scraper and a cloth dampened in cleaning solvent
(FED. Spec. P-D-680). Be very careful not to get dirt
in the cylinders or water jacket.
(3) Inspect the cylinder head for cracks,
corrosion, damaged threads, plugged water ports, or
other defects.
(4) Check flatness lengthwise with a
straightedge and feeler gage.
The maximum,
permissible low spot is 0.012 inch in the center,
Figure 4-2. Cylinder head cap screw tightening sequence.
b.
4-4.
Intake and Exhaust Valves
a. General. The intake and exhaust valves of
this L-head engine are mounted in the cylinder block.
They are opened by operation of the camshaft through
adjustable valve tappets. They are closed by the valve
springs. The valve stems ride in valve guides which are
pressed into the block. The intake valves seat directly
in the block. The exhaust valve seat in shrink-fit valve
seat inserts in the block.
Removal.
(1) Remove the cylinder head (para 4-3).
(2) Remove the valve chamber cover (7,
fig. 4-22).
(3) Using a spring lifter, compress the
valve spring (5 or 10, fig. 4-3) at each valve (2 or 7)
and remove the valve locks (1 or 6) from each valve
that is in the closed position. Rotate the engine
crankshaft to close the remaining valves and remove
the remaining locks.
4-6
TM 5-4320-258-34
Figure 4-3. Valves and camshaft, exploded view.
4-7
TM 5-4320-258-34
(4) Lift each valve from the top of the
block. Place valves in order in a rack to assure that
each will be reassembled in the same valve guide from
which it was removed.
(5) Remove the valve rotators (3 or 8),
spring retainers (4 or 9), and valve springs (5 or 10).
Remove the valve tappet assemblies (13).
(6) Do not remove the valve guides (11) or
valve seat inserts (12) unless inspection indicates that
they are faulty.
c. Cleaning, Inspection, and Repair.
(1) Clean the valves, valve springs, and
valve tappet assemblies with cleaning solvent (FED.
Spec. P-D-680); dry thoroughly. Remove carbon
deposits with a wire brush.
(2) Clean the valve guides installed in the
block with a valve guide cleaner or wire brush. Remove
all lacquer and other deposits.
(3) Clean the valve seats with a wire brush.
(4) Inspect the valves for cracks, bent
stems, distortion, and wear (table 4-1). If the valves are
not seriously damaged, regrind them. After grinding, the
valve head thickness must be at least 50 percent the
thickness of a new valve. Replace the valves if they are
ground to less than this amount. Check the reground
valves on V-blocks with an indicator. The contact face
must be true with the stem to within 0.002 inch.
(5) Check for loose or worn valve guides.
Check the internal diameter of the valve guide with a
telescope gage and a micrometer. Replace guides that
are worn to a bell-mouthed shape or guides that have a
maximum diameter of more than 0.3447 inch.
Caution: Do not attempt to ream the valve
guides after seating them. Guides are pre reamed
and coated.
Further reaming will remove the
coating.
(6) If the valve guides are worn or
damaged, press out the guides from the combustion
side, using a driver that is slightly smaller than the
external diameter of the guide. With the driver, press in
new guides from the combustion side. When properly
seated, valve guide tops will be 1 13 / 32 inches from
the top of the block (fig. 4-4).
Figure 4-4. Valve guide installation dimensions.
(7) Check the exhaust valve seat inserts
for cracks or loose mounting. Pull out faulty valve seat
inserts. Replace original valve seats with new 0.010inch oversized valve seats. Counterbore the original
valve seats to a diameter of 1.3535 to 1.3545 inches.
This will provide the required press fit. If valve seats
have been counterbored previously, rebore to 0.01 inch
oversize to provide an 0.003- to 0.005-inch press fit.
Counterbore deeply enough so that the boring tool will
clean up the bottom of the bore to assure proper heat
conduction from the valve insert. Chill the valve seats
in dry ice for 20 minutes. Install the valve seat in place
with a piloted driver, using an arbor press or by applying
light blows with a hammer until the valve seat is resting
against the bottom of the bore. Roll or peen the valve
seat in place.
(8) Check the valve springs for cracks and
distortion.
Intake and exhaust valve springs are
identical. Test compression strength with a spring
tester. Compression strength must be as follows:
4-8
TM 5-4320-258-34
Length
1-45 / 64 inches (closed)
1-27 / 64 inches (open)
Load (minimum)
42 pounds
86 pounds
valve is installed in the guide from which it was
removed.
(3) With the engine stopped, temporarily
set the intake-valve-to-tappet clearance to 0.014 inch
and the exhaust valve-to-tappet clearance to 0.017 inch
(cold).
(4) Install the cylinder head (para 4-3).
(5) Operate the engine until it reaches
operating temperature. Adjust valve tappet clearance
as directed in subparagraph e below.
(6) Install the valve chamber cover (7, fig.
4-22).
e. Valve Adjustment.
(1) Operate engine until it reaches
operating temperature.
(2) Disconnect the positive crankcase
ventilation valve and fittings from the valve chamber
cover.
(3) Remove the nuts and washers that
secure the valve chamber cover to the cylinder block.
Remove the valve chamber cover and gasket.
(4) With the engine at operating
temperature: and running at idle speed, set the intake
valves for; 0.014-inch clearance as follows:
(a) Alternately pass a 0.013-inch and
a 0.015-inch flat feeler gage between the head of the
adjusting screw of the tappet (13, fig. 4-3) and stem of
valve (2).
(b) If a 0.013-inch feeler gage moves
freely back and forth in gap when the valve is not being
lifted and 0.015-inch feeler gage binds at all times, the
clearance requires no adjustment.
(c) If a 0.013-inch feeler gage is
gripped at all times, the clearance is insufficient.
(d) Hold valve lifter with an open end
wrench while using a second wrench to turn adjusting
screw one-quarter to one-half turn clockwise. Repeat
clearance check and adjustment until proper clearance
is obtained. The adjustable-type valve lifters have selflocking adjusting screws that require no lock nuts.
(e) If 0.015-inch feeler gage moves
freely when valve is not being lifted, the clearance is too
great. 'Hold valve lifter with an open end wrench while
using a second wrench to turn valve lifter adjusting
screw counterclockwise one-quarter to one-half turn.
Repeat the clearance check, and adjustment until proper
clearance is obtained.
(5) Adjust the exhaust valves to a 0.016
(hot) clearance in the manner described above, using
0.015and 0.017-inch feeler gage.
4-5.
Intake and Exhaust Manifolds
a. Removal and Disassembly.
(1) Remove the carburetor from the intake
manifold (TM 5-4320-258-12).
(9) Grind the valve seats. The seat angle
of the intake valves is 30°. The seat angle of the
exhaust valve is 45°. Use a dial indicator to check the
valve seat for runout. The total indicator reading must
not exceed 0.002 inch. Clean the valve seat and
surrounding area thoroughly after grinding.
(10) After the valves and seats have been
refaced and reground, coat the seat lightly with Prussian
blue 'and drop the valve into place, oscillating it slightly
to transfer the blue pattern to the valve face. This
should show a contact width of 1/ 16 to 3/ 32 inch, and
should fall well within the width of the valve face,
leaving at least 1 / 64 inch on either side of the contact
area. If the contact area is greater than 3 / 32 inch,
narrow the contact area by grinding the outside diameter
of the seal with a 15° stone or by grinding the inside
diameter of the seat with a 60° or 75° stone (fig. 4-5).
After the seat area is corrected, touch the seat lightly
with the original grinding stone to remove the burred or
feathered edge.
Figure 4-5. Narrowing valve seat.
(11) Inspect the spring retainer seats,
spring retaining locks, valve stem caps, and valve
tappet assemblies for cracks, scoring, overheating, and
wear. Replace damaged parts.
d. Installation.
(1) Position the valve tappet assemblies
(13, fig. 4-3) in the engine block.
(2) Assemble-the valves (2 and 7), valve
springs (5 and 10), spring retainers (4 and 9), valve
rotators (3 and 8), and valve locks (1 and 6). Compress
the valve springs with a spring compressor to install the
valve locks. Turn the engine over as necessary to allow
each valve to move to the closed position before
attempting to install the valve parts. Make sure each
4-9
TM 5-4320-258-34
(2) Remove the exhaust piping from the
exhaust manifold (TM 5-4320-258-12).
(3) Refer to figure 4-6 and remove and
disassemble the intake and exhaust manifolds.
Figure 4-6. Intake and exhaust manifolds, exploded view.
4-10
TM 5-4320-258-34
c.
Reassembly and Installation.
(1) Reassembly is the reverse of
disassembly. Use new gaskets. Refer to figure 4-6.
When tightening the manifold mounting nuts, torque
them to 25 to 30 foot-pounds.
(2) Install the exhaust piping and muffler
(TM 5-4320-258-12).
(3) Install the carburetor (TM 5-4320-25812).
(4) After the engine has been run at
operating temperature and has cooled, recheck the
torque of the mounting nuts. If necessary, retighten
them to 25 to 30 foot-pounds torque.
4-6.
Oil Pan and Filler Blocks
a. Removal.
(1) Remove the drain plug (1, fig. 4-7) and
drain the engine oil into a suitable container. Remove
the oil drain piping (items 2 through 5).
b.
Cleaning and Inspection.
(1) Discard and replace all gaskets.
(2) Clean the intake manifold and heat
control valve and related parts with cleaning solvent
(FED. Spec. P-D-680). Dry thoroughly.
(3) Clean the exhaust manifold with a wire
brush.
Remove greasy or gummy deposits with
cleaning solvent.
(4) Inspect the intake and exhaust
manifolds for cracks, distortion, broken mounting
flanges, damaged threads, and other damage; replace
damaged manifolds.
(5) Inspect the heat control valve parts for
corrosion and burning. Check the fit of the heat control
valve shaft in the bushings. There shall be no binding,
nor shall there be excessive bushing-to-shaft play.
Replace bushings or shaft if necessary to correct
defects.
(6) Remove and replace any damaged
studs.
KEY to fig. 4-7:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
4-11
Oil drain plug
Gasket
Coupling
Nipple
Elbow
Cap screw
Lock washer
Oil pan
Oil pan gasket
Cap screw
Lock washer
Front filler block seal
Front filler block
Cap screw
Lock washer
Rear filler block seal
Rear filler block
Oil guard seal
Rear oil guard
TM 5-4320-258-34
Figure 4-7. Oil pan and filler blocks, exploded view.
4-12
TM 5-4320-258-34
parallel to the flat surface of the casting.
(2) To replace the neoprene seals (12 and
16) on the filler blocks (13 and 17), make sure the
contact surface is free of cement, dirt, and oil. To hold
the seal in place for assembly, use a small spot of
nonhardening cement in the center of the contacting
surface before inserting the seal in the groove. No other
cement is required.
(3) Lubricate all seals with engine oil. With
the crankshaft in place, the assembled rear oil guard
(19) and jute seal (18) can be rolled into place around
the crankshaft. Position the assembled rear filler block
(17) and seal (16) on the engine block; secure with the
two cap screws (14) and lock washers (15). Tighten the
cap screws to 15 to 20 foot-pounds torque.
(4) Position the front filler block (13) and
seal (12) on the engine block; secure with the two cap
screws (10) and lock washers (11). Tighten the bolts to
15 to 20 foot-pounds torque.
(5) Position the gaskets (9) on the oil pan
(8). Install the oil pan and gaskets on the engine block;
secure with the 18 cap screws (6) and lock washers (7).
Tighten the screws to 15 to 20 foot-pounds torque.
4-7.
Engine Oil Pump
a. Removal and Disassembly.
(1) Remove the engine oil pan (para 4-6).
(2) Remove the nut (1, fig. 4-8) and lock
washer (2) that secure the engine oil pump to the
bearing cap; remove the oil pump and flat washer (3).
(3) Disassemble the oil pump as shown in
figure 4-8.
(2) Remove the 18 screws (6) and lock
washers (7) that secure the oil pan (8) to the block;
remove the oil pan and gaskets (9).
(3) Remove the two cap screws (10) and
lock washers (11) that secure the front filler block (13) to
the block; remove the filler block and seal (12).
(4) Remove the two cap screws (14) and
lock washers (15) that secure the rear filler block (17) to
the block; remove the filler block and seal (16), oil guard
seal (18), and oil guard (19).
b. Cleaning and Inspection.
(1) Discard and replace gaskets and seals.
(2) Clean all remaining parts with cleaning
solvent (FED. Spec. P-D-680); dry thoroughly.
(3) Inspect the oil pan for cracks, severe
dents, holes, damaged threads, and other damage;
replace a damaged oil pan.
(4) Inspect the filler blocks for cracks,
distortion, and other damage; replace damaged filler
blocks.
c. Installation.
(1) Install the seal (18, fig. 4-7) in the rear
filler block (17) and oil guard (19) as follows:
(a) Flatten the jute seal in a vise or
with a hammer until the seal fits into the groove in the
filler block or oil guard.
(b) Roll the seal into the oil guard or
filler block groove with a round object.
(c) Trim the seal 0.020 to 0.030 inch
above the flat surface of the oil guard or filler block,
using a sharp knife or razor blade. Make sure the cut is
KEY to fig. 4-8:
1. Nut
2. Lock washer
3. Flat washer
4. Screen
5. Cap Screw
6. Lock Washer
7. Spacer
8. Strainer frame
9. Frame-to-cover gasket
10. Cap screw
11. Lock washer
12. Cover
13. Cover gasket
14. Pin
15. Drive gear
16. Retaining ring
17. Driver gear
18. Key
19. Drive shaft
20. Idler gear
21. Idler gear stud
22. Body bushing
23. Oil pump body
24. Stud
25. Crankshaft bushing
4-13
TM 5-4320-258-34
Figure 4-8. Engine oil pump, exploded view.
4-14
TM 5-4320-258-34
c.
Reassembly and Installation.
(1) Refer to figure 4-8 and reassemble the
engine oil pump. Check that the drive shaft turns easily
without binding when assembled.
(2) Position the washer (3, fig. 4-8) and oil
pump on the main bearing so that the drive gear
engages the toothed portion of the camshaft; secure the
pump with a nut (1) and lock washer (2).
(3) Install the oil pan (para 4-6).
4-8.
Gear Cover
a. Removal and Disassembly.
(1) Remove the governor from the engine
(TM 5-4320-258-12).
(2) Remove the water pump from the
engine TM 5-4320-258-12).
(3) Remove the starting jaw (1, fig. 4-14)
and collar (2) that secure the pulley (3) to the front end
of the crankshaft; remove the pulley and key (4) from
the crankshaft.
(4) Remove the cap screws (1, 3, 6, 8, and
11, fig. 4-9), assembled washer screw (5), nuts (10, 13,
and 14), lock washers (2, 9, 12, and 15), and copper
washers (4 and 7) that secure the gear cover (17) to the
engine block; remove the gear cover from the engine
block.
(5) Press the seal (16) from the gear cover.
b.
Cleaning and Inspection.
(1) Discard and replace all gaskets.
(2) Clean all parts with cleaning solvent
(FED. Spec. P-D-680); dry thoroughly.
(3) Inspect the strainer screen for holes,
clogging, and distortion; replace a damaged strainer
screen.
(4) Inspect the gears for chipped or broken
teeth, scoring, and wear. With the gears mounted on
their respective shafts, there shall be no contact
between the gears and the pump body. Clearance
between gears shall be 0.001 inch minimum to 0.003
inch maximum. Replace parts if they fail to meet these
requirements.
(5) With the gears positioned in the body
and a new gasket positioned on the face of the pump
body, place a straightedge across the open face of the
body and, with a feeler gage, check the possible end
play of the gears. It shall be 0.0015 to 0.006 inch. If
clearance is not within this range, replace parts as
required.
(6) Check the fit of the drive shaft in the
pump body. There shall be no excessive play. Replace
the body bushing if play is excessive.
(7) Inspect the gear pockets of the body. If
they are scored, or excessively worn, replace the pump.
(8) Inspect all remaining parts for cracks,
distortion, damaged threads, wear, and other damage;
replace damaged parts.
4-15
TM 5-4320-258-34
Figure 4-9. Gear cover and front end plate, exploded view.
b.
(4) Inspect all other parts for cracks,
distortion, worn or damaged threads, and other damage:
replace damaged parts.
c. Reassembly and Installation.
(1) Refer to figure 4-9, items 1 through 18,
and install the gear cover.
(2) Secure the crankshaft pulley (3, fig. 414)
Cleaning and Inspection.
(1) Discard and replace all gaskets and
seals.
(2) Clean all parts with cleaning solvent
(FED. Spec. P-D-680); dry thoroughly.
(3) Inspect the gear cover for cracks,
distortion, damaged sealing surfaces, and other
damage; replace a damaged gear cover.
4-16
TM 5-4320-258-34
to the crankshaft, using the starting jaw (1) and collar
(2).
(3) Install the governor on the engine (TM
5-4320-258-12). Time the magneto (TM 5-4320-25812).
4-9.
Flywheel and Flywheel Housing
a. Removal.
Remove the flywheel and
flywheel housing as follows:
(1) Remove the six nuts (5, fig. 4-14) and
lock washers (6) that secure the flywheel (7) and ring
gear (8) to the crankshaft (40); remove the flywheel.
(2) Remove the cap screws (11, fig. 4-22),
shoulder screws (13), and lock washers (12 and 14) that
secure the flywheel housing (15) to the block (35);
remove the flywheel housing and gasket.
b. Cleaning, Inspection, and Repair.
(1) Clean the flywheel and flywheel
housing with cleaning solvent (FED. Spec. P-D-680);
dry thoroughly.
(2) Inspect the flywheel housing for cracks,
distortion, and damaged threads; replace a damaged
flywheel housing.
(3) Inspect the flywheel for chipped,
cracked, or broken teeth on the ring gear, distortion,
worn or out-of-round bolt holes, and other damage. If
the ring gear is damaged, replace as follows:
Caution: When cutting the ring gear, be
extremely careful not to damage the flywheel.
(a) Cut the ring gear with a torch or
hack saw and remove the ring gear from the flywheel.
(b) Heat the replacement ring gear in
an oven and cool the flywheel in water or in a
refrigerator.
(c) Position the replacement ring gear
on the flywheel. As the ring gear and flywheel approach
the same temperature, the ring gear will contract to a
tight fit on the flywheel.
c. Installation.
(1) Position the flywheel housing (15, fig.
4-22) on the block (35); secure with shoulder screws
(13), cap screws (11), and lock washers (12 and 14).
(2) Position the flywheel (7, fig. 4-14) on
the crankshaft (40); secure with six bolts (9), lock
washers (6), and nuts (5). Tighten the nuts to 35 to 40
foot-pounds torque.
(3) Check flywheel runout by mounting a
dial indicator so that it indicates the flat vertical surface
of the flywheel (figure 4-10); rotate the crankshaft
through one full revolution. Hold pressure against the
flywheel to eliminate crankshaft end play. If flywheel
runout exceeds 0.008 inch, remove the flywheel and
clean the crankshaft flange and flywheel seat. Install
the flywheel and recheck runout. If runout still exceeds
0.008 inch, replace the flywheel.
Figure 4-10. Checking flywheel runout.
(4) Check flywheel eccentricity by
mounting a dial indicator so that it indicates the inside
diameter of the flywheel counterbore (fig. 4-11); rotate
the crankshaft through one revolution. If the flywheel is
eccentric more than 0.008 inch, loosen and retighten the
flywheel mounting bolts and recheck eccentricity. If
eccentricity still exceeds 0.008 inch, replace the
flywheel.
Figure 4-11. Checking flywheel eccentricity.
(5) Check runout of the flywheel housing
face by mounting a dial indicator so that it indicates the
housing face (fig. 4-12); rotate the crankshaft through
one revolution. Hold pressure against the flywheel to
eliminate end play. If runout exceeds
4-17
TM 5-4320-258-34
0.008 inch, clean the mounting surfaces of the flywheel
housing and the block. Recheck flywheel housing
runout. If the runout is still not within limits, replace the
flywheel housing.
Figure 4-13. Checking flywheel housing eccentricity.
4-10.
Pistons and Connecting Rods
a. Removal and Disassembly. With the
engine mounted on an engine overhaul stand, proceed
as follows:
(1) Remove the cylinder head (para 4-3).
(2) Remove the engine oil pan (para 4-6)
and oil pump (para 4-7).
(3) Ream the ridge of the top of each
cylinder bore with a standard ridge reamer. Blow metal
fragments from the cylinder with compressed air.
(4) Remove the two cotter pins (10, fig. 414) and nuts (11) that secure a bearing cap (13) to a
connecting rod (20); remove the cap and bearing shells
(14).
Caution: While pushing the piston and rod
from the block, be very careful the connecting rod
does not scratch the cylinder wall.
(5) Push assembled piston (18), rings (17),
and connecting rod (20) up through the top of the block.
(6) Refer to figure 4-14 (items 15 through
20) and disassemble the piston and connecting rod.
Figure 4-12. Checking flywheel housing runout.
(6) Check eccentricity of the flywheel
housing bore by mounting a dial indicator so that it
indicates the bore (fig. 4-13); rotate the engine through
one revolution. If the housing bore is eccentric more
than 0.008 inch, loosen the flywheel housing mounting
bolts and tap the housing into its proper position with a
soft hammer. Tighten the bolts and recheck eccentricity
of the housing bore. If the housing cannot be brought
into true position, replace the housing.
Note. Disassemble the pistons and piston
rods in sets, and keep the sets together. Also, be sure
each piston and piston rod set is installed in the cylinder
from which it was removed.
4-18
TM 5-4320-258-34
Figure 4-14. Piston, crankshaft, and flywheel, exploded view.
4-19
TM 5-4320-258-34
loose piston pin-to-piston fit, and other damage; replace
damaged pistons. Refer to table 4-1 for wear limits.
(4) Check the piston ring groove side
clearance, using new piston rings. If side clearance
exceeds the limits cited in table 4-1, replace the piston.
KEY to fig. 4-14:
1.
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.
34.
35.
36.
37.
38.
39.
40.
Starting jaw
Collar
Pulley
Key
Nut
Lock washer
Flywheel
Ring gear
Flywheel bolt
Cotter pin
Nut
Connecting rod bolt
Bearing cap
Connecting rod bearing shell
Retaining ring
Piston pin
Piston ring set
Piston
Sleeve bearing
Connecting rod
Oil thrower
Crankshaft gear
Key
Thrust plate
Lock wire
Intermediate bearing capbolt
Intermediate bearing cap
Ring dowel
Intermediate main bearing
Bearing cap bolt
Flat washer
Rear bearing cap
Rear main bearing
Front bearing cap
Dowel
Front main bearing
Front intermediate main bearing cap
Dowel
Front intermediate main bearing
Crankshaft
Note: Pistons and bearings are individually
checked and fitted to the cylinders at reassembly.
Before reassembly, the cylinder bores must be checked
as directed in paragraph 413c.
(5) Inspect the connecting rods for cracks,
distortion, and other damage: replace damaged
connecting rods. Refer to table 4-1 for wear limits.
(6) Inspect the bearing shells for scoring,
wear, cracks, and other damage.
Check bearing
thickness, using a ball micrometer. Thickness must not
be less than 0.0608 in all areas.
Note: New bearing shells are smooth and
highly polished. After a few hours of operation, the
bearing surface becomes a leaden grey and develops
minute craters so that the bearing surface has an almost
cellular appearance. This is normal, and is not an
indication of impending bearing failure.
(7) Inspect all other parts for cracks,
scoring, damaged threads, and other damage; replace
damaged parts.
c. Reassembly and Installation.
(1) Check piston fit in the cylinder bore (fig.
4-15), using a piece of 0.003-inch feeler stock cut 1/2
inch wide. Dress the edges of the feeler stock with a
stone to remove burrs and feathered edges. The block
and pistons must be at room temperature when piston fit
is tested. Position the feeler stock midway between the
piston pin bosses. With the piston inserted about 2
inches into the block, the feeler stock must pull from the
block with 5 to 10 pounds pull. If the feeler stock does
not offer enough resistance, perform the same test with
a new standard size piston. If sufficient resistance is still
not obtained, rebore the cylinders (para 4-13) and install
oversize pistons.
b.
Cleaning and Inspection.
(1) Discard and replace the piston rings.
(2) Clean all parts with cleaning solvent
(FED. Spec. P-D-680); dry thoroughly.
(3) Inspect the pistons for cracks,
distortion, broken ring bands and distorted grooves,
4-20
TM 5-4320-258-34
Figure 4-15. Checking piston fit in cylinder bore.
(6) Install the oil ring in the bottom ring
groove of each piston as follows:
(a) Place stainless steel expander
spacer in groove with ends butted.
(b) Install steel segment on top side of
expander spacer with gap of segment approximately 90°
beyond gap of stainless steel expander spacer, making
certain that the expander spacer ends are still in a
butted position.
(c) Install second segment on bottom
side of the expander spacer with segment gap
approximately 90° from the expander gap in opposite
direction from which the top segment has been installed.
(d) Recheck assembly. Rings should
be free to move in the groove; however, a slight drag
will be evident because of the side sealing action of the
ring assembly. Be sure expander spacer ends remain
butted.
(7) Install the remaining piston rings on the
piston with a standard ring expander tool.
(8) Assemble the remaining pistons,
connecting rods, and piston rings.
(9) Install the assembled pistons and
connecting rods in the same cylinders from which they
were originally removed. Use a ring compressor to
compress the piston rings. Lubricate the pistons and
cylinder walls with engine oil before installing the
pistons. Wrap the bottom end of the connecting rods
with a cloth to prevent damage to the cylinder walls
during installation.
(2) If new pistons (18, fig. 4-14) and piston
pins (16) are being used, press a new sleeve bearing
(19) into each connecting rod (20). Ream and hone the
sleeve bearings to 0.8595- to 0.8597-inch diameter.
Make sure the final operation is done with a hone so that
75 percent of more of bearing surface contacts the
piston pin.
(3) If the pistons and pins are not being
replaced, check the clearance between the piston pins
and the sleeve bearings. Clearance must be between
0.0002 and 0.0006 inch. If clearance is not within this
tolerance, press new sleeve bearings into the
connecting rods and ream and hone to provide the
proper clearance. After honing, 75 percent of the sleeve
bearing surface must contact the piston pin.
(4) When pins, bushings, and pistons of the
proper size have been found, assemble the pistons to
the connecting rods as follows:
(a) Heat the pistons and connecting
rods in an oven or in water to a minimum of 160°F.
(b) Position a connecting rod in its
piston. Install the piston pin; secure with the piston pin
retaining ring (15, fig. 4-14).
(5) Slide the piston rings (17) squarely into
the cylinders in which they will be used. Check the ring
gap with feeler gage. If the ring gap is not at least 0.007
inch, file the rings to provide a larger gap. If the ring
gap exceeds 0.017 inch, rebore the cylinders (para 4-13)
and install oversize pistons and rings.
4-21
TM 5-4320-258-34
Rotate the crankshaft and roll the bearing shell from the
cylinder block.
(10) Check the crank pin bearing journalto-connecting rod bearing clearance with plastigage.
Lay a piece of plastigage material on the crankshaft
journal and install the connecting rod bearing cap.
Torque the nuts to 35 to 40 foot-pounds. Remove the
bearing cap and compare the width of the flattened
plastigage material with the scale markings on the
plastigage package to determine the clearance. The
bearing-to-journal clearance shall be 0.0006 to 0.0022
inch. If clearance is beyond these limits, replace the
bearing and/or the crankshaft as required.
(11) As an alternate method of checking
crank pin bearing journal-to-connecting rod bearing
clearance, install a 1/2-inch piece of 0.0022-inch-thick
feeler stock between the bearing and journal, and install
the bearing cap. Tighten the connecting rod cap bolts to
35 to 40 foot-pounds torque. Rotate the crankshaft to
detect drag. If clearance is within tolerance, a definite
drag will be felt. Disassemble the rod cap and remove
the shim stock. If clearance is not within tolerance,
replace the connecting rod bearings and recheck the
clearance. If clearance is still not within tolerance,
replace the crankshaft.
(12) Lubricate the crank pin bearing
journals and the sleeve bearings with engine oil. Install
the cap (13, fig. 4-14) on its connecting rod (20) and
crank pin bearing journal; secure with the two bolts (12)
and nuts (11). Tighten the nuts to 35 to 40 foot-pounds
torque. Install the cotter pins (10).
(13) Secure the remaining connecting rods
to !the crank pin bearing journals.
(14) Install the engine oil pan (para 4-6c).
(15) Install the cylinder head (para 4-3 c).
4-11. Main Bearings and Crankshaft.
a. Removal and Disassembly.
With the
engine mounted on an engine overhaul stand, proceed
as follows:
(1) Remove the cylinder head (para 4-3 a).
(2) Remove the oil pan (para 4-6 a) and oil
pump (para 4-7 a).
(3) Remove the gear cover (para 4-8a).
(4) Remove the flywheel and flywheel
housing (para 4-9 a).
(5) Remove the pistons and connecting
rods (para 4-10 a).
(6) Remove the bolts (26 and 30, fig. 4-14)
and flat washers (31 ) that secure the main bearing caps
(27, 32, 34, and 37) to the cylinder block. Loosen the
bearing caps by tapping them with a plastic hammer.
Remove the bearing caps and lower bearings (29, 33,
36, and 39).
Figure 4-16. Removing upper bearing shell with angular
pin.
(7) Pull the oil thrower (21, fig. 4-14) and
gear (22) from the crankshaft (40). Remove the key
(23) and remove the thrust plate (24).
b. Cleaning and Inspection.
(1) Clean all parts with cleaning solvent
(FED. Spec. P-D-680). Clean oil passages in the
crankshaft with a rifle cleaning brush. Make sure all
passages are open.
(2) Inspect the crankshaft for cracks, worn
or scored journals, damaged threads, and burred
keyways. Refer to table 4-1 for wear limits. If magnetic
particle inspection equipment is available, use it to
check the crankshaft for hidden flaws. Replace a
damaged crankshaft.
(3) Inspect the gear for cracked, chipped
and broken teeth; replace a damaged gear.
(4) Inspect the bearing shells for cracks
and scoring. New bearings are smooth and highly
polished. After a few hours of operation, the bearing
surfaces become leaden grey in color and develop
minute craters which give the bearing surfaces an
almost cellular appearance.
This is a natural
characteristic of the bearing and does not indicate
bearing failure. Replace bearings if they are scored or
damaged. Check the bearing thickness with a ball
micrometer. Check several locations on the bearing. If
thickness is less than 0.920 inch, replace the bearing.
(5) Inspect the bearing caps for cracks and
distortion and for burrs and gouges of the seating
surfaces. Clean up any burrs with a fine stone to assure
proper seating of the bearing cap on the block.
Note: Upper main bearing shells can be
removed without removing the crankshaft. To remove
the upper shell, remove the main bearing cap at the
defective bearing and remove the lower bearing shell.
Insert a pin with an angular head in the oil hole of the
crankshaft as shown in figure 4-16.
4-22
TM 5-4320-258-34
(6) Clearance must be between 0.0008 and
0.0028 inch. If the clearance is not within these limits,
replace the bearings and recheck the clearance.
(7) Remove and replace the bearings as
follows:
(a) Remove the bearing cap; remove
the bearing from the cap.
(b) Install a pin with an angular head
in the oil hole in the crankshaft bearing journal (fig. 416).
(c) Rotate the crankshaft by hand.
The pin will force the top bearing half out of its seat.
(d) Position the replacement bearing
on the crankshaft bearing journal. Rotate the crankshaft
by hand. The pin will force the bearing half into position
as shown in figure 4-18.
c.
Reassembly and Installation.
(1) Install the rear oil seal and oil guard as
directed in paragraph 4-6 c.
(2) Position the thrust plate (24, fig. 4-14)
on the crankshaft and install the key (23) in the keyway
of the crankshaft, after making sure that the keyway is
free of burrs. Press the gear (22) onto the crankshaft.
Install the oil thrower (21).
(3) Position the upper half of the main
bearings (29, 33, 36, and 39) in the seats in the
crankcase. Position the crankshaft in the bearing shells.
Caution: When installing the crankshaft,
make sure the timing marks on the crankshaft gear
are alined with the timing marks on the camshaft
gear. See paragraph 4-12.
(4) Install the lower half of the main
bearings in the bearing caps (27, 32, 34, and 37).
(5) Check the clearance between the
crankshaft bearing journals and bearings as follows:
(a) Place a piece of plastigage near
the oil hole of the bearing cap.
(b) Position the cap on the block and
secure with the two screws and lock washers. Tighten
the screws to 85 to 95 foot-pounds torque.
(c) Remove the bearing and bearing
cap. Check the bearing journal-to-bearing clearance
indicated by the plastigage (fig. 4-17).
Figure 4-18. Installing upper bearing half, using angular
pin.
(e) Install the replacement bearing
half in the cap. Install the cap.
(8) Check the remaining bearing-to-bearing
journal clearances and replace bearings as necessary.
(9) An alternate method of checking
bearing clearance is as follows:
(a) Oil the bearing and bearing journal
with engine oil.
(b) Position a strip of 0.003-inch feeler
gage, 1/2 inch long, on the bearing cap (fig. 4-19).
Figure 4-17. Checking bearing clearance with
plastigage.
4-23
TM 5-4320-258-34
b.
Cleaning and Inspection.
(1) Clean all parts with cleaning solvent
(FED. Spec. P-D-680); dry thoroughly.
(2) Inspect the camshaft for cracks, worn or
scored cams worn or scored bearing surfaces, chipped,
cracked, or broken gear teeth, and clogged oil
passages. Refer to table 4-1 for wear limits.
Replace a damaged camshaft.
(3) Inspect the thrust washer for scoring
and wear. Replace the thrust washer if any signs of
wear are evident.
(4) Inspect the cam gear for cracked,
chipped, or broken gear teeth, damaged shaft bore, or
worn thrust surface. The cam gear and the mating gear
on the crankshaft must be replaced as a pair. Do not
attempt to replace these gears singly.
(5) Inspect the plug (33, fig. 4-22) in the
cylinder block. Replace if any leaking is evident from
the circumference of the plug.
(6) Inspect the camshaft bearings in the
cylinder block for scoring or visible damage; replace
damaged bearings if necessary. Check the camshaft-tobearing clearance and, if necessary, replace bearings as
follows:
Figure 4-19. Checking bearing clearance with shim
stock.
(c) Install the cap on the block; secure
with the screws and lock washers. Tighten the screws to
85 to 95 foot-pounds torque.
(d) Try to turn the crankshaft by hand.
If the crankshaft will not turn or a very definite drag is
felt, bearing-to-bearing journal clearance is within
tolerance. Remove the shim stock and reinstall the
bearing caps.
(10) After all main bearings have been
installed, use a dial indicator to check crankshaft end
play. If end play is not between 0.003 and 0.008 inch,
replace the thrust plate (24) which controls the shaft end
play..
(11) Install the pistons and connecting rods
(para 4-10c).
(12) Install the flywheel housing and
flywheel (para 4-9c).
(13) Install the gear cover (para 4-8c).
(14) Install the oil pan (para 4-6c) and oil
pump (para 4-7c).
(15) Install the cylinder head (para 4-3c).
4-12. Camshaft
a. Removal. With the engine removed from
the pump assembly and mounted on an engine stand,
proceed as follows:
(1) Remove the cylinder head (para 4-3a).
(2) Remove the valves and valve tappets
(para 4-4b).
(3) Remove the gear cover (para 4-8a).
(4) Remove the nut (14, fig. 4-3) from the
camshaft (20) and pull the gear (15) from the cam shaft.
(5) Remove the two cap screws (17) and
lock washers (18) that secure the thrust plate (19) to the
block; remove the thrust plate.
(6) Pull the camshaft (20) from the block.
Caution: Do not insert the camshaft too far
into the block.
If the camshaft bumps the
expansion plug on the drive end of the engine, an
oil leak could result.
(a) Temporarily insert the camshaft
(20, fig. 4-3) in the block. Check the clearance between
the camshaft bearing journals and camshaft bearings
(21, 22, 23, and 24) with feeler stock cut in strips 1/4
inch wide. Dress the feeler stock with a stone to
eliminate burrs or feathered edges. Clearance between
bearings and journals must be between 0.002 and 0.004
inch.
(b) If clearance exceeds tolerances,
remove the camshaft and remove the camshaft
bearings. New bearings are pre-reamed. Install new
bearings, taking care to aline the oil holes with the
passages in the block. Use caution to prevent damage
to the bearings during installation.
c. Installation.
(1) Lubricate the camshaft bearings with
engine oil and install the camshaft in the block. Position
the thrust plate (19, fig. 4-3) on the camshaft; secure
with two cap screws (17) and lock washers (18).
Caution: When installing the camshaft gear,
do not attempt to seat the gear by tightening the
retaining nut. This may break threads on the
camshaft, requiring camshaft replacement.
(2) Hold the camshaft toward the front of
the engine with a bar inserted into the fuel pump hole.
Aline the timing marks on the camshaft and crankshaft
gears (fig. 4-20) and drive the gear (15, fig. 4-3) onto
the camshaft.
4-24
TM 5-4320-258-34
Figure 4-21. Checking for insufficient timing gear
clearance.
(5) If gear clearance is too great or too
small, the gears must be replaced. Replace the gears
only in sets. Gear sets are available in standard size
(marked S), 0.002 and 0.004 inch undersize (marked U),
and 0.002 and 0.004 inch oversize (marked O). Install a
gear set marked the same as the set removed. Check
the clearance as directed in (4) above. If clearance is
too great, install the next smaller size gear set. If
clearance is insufficient, install the next larger size set.
(6) Install the gear cover (para 4-8c).
(7) Install the valves and valve tappets
(para 4-4c).
(8) Install the cylinder head (para 4-3c).
4-13. Cylinder Block
a. Removal and Disassembly.
With the
engine mounted on an engine overhaul stand, proceed
as follows:
(1) Remove the cylinder head (para 4-3a).
Figure 4-20. Timing gears showing alinement marks.
(3) Check camshaft, end play with a dial
indicator. If end play is .not between 0.005 and 0.009
inch, remove the camshaft timing gear and, replace the
thrust plate (19, fig. 4-3).
(4) Check the clearance between the
camshaft and crankshaft gears as follows:
(a) Force the teeth of the gears apart
with a screwdriver. Attempt to insert a 0.002-inch feeler
gage into the gap between the gears. If the gage will
enter, the clearance is excessive.
(b) If the gage will not enter, place a
finger at the junction of the two gears as shown in figure
4-21 and tap the camshaft gear with a hammer. If
vibrations can be felt in the large gear, the clearance is
sufficient.
4-25
TM 5-4320-258-34
(7) Remove the crankshaft and main
bearings (para 4-11a).
(8) Remove the camshaft (para 4-12a).
(9) Remove the assembled washer screw
(19, fig. 4-9), cap screws (20), and flat washers (21)
that secure the front end plate (22) to the cylinder block;
remove the backing plate and gasket (23).
(10) Remove the plug (33, fig. 4-22) and
gasket (24); remove the spring (25), washers (26), and
oil pressure relief valve (27).
(2) Remove the intake and exhaust valves
(para 4-4b) and intake and exhaust manifolds (para 45a).
(3) Remove the oil pan (para 4-6a) and oil
pump (para 4-7a).
(4) Remove the gear cover (para 4-8a).
(5) Remove the flywheel and flywheel
housing (para 4-9a).
(6) Remove the pistons and connecting
rods (para 4-10a).
4-26
TM 5-4320-258-34
Figure 4-22. Cylinder block and flywheel housing, exploded view.
4-27
TM 5-4320-258-34
(3) Check cylinder bore wear with an inside
micrometer. Measure the cylinder bore at 45° intervals
below the travel of the lowest piston ring where the
cylinder is not worn. Compare this measurement with a
measurement taken about 1/4 inch below the top of the
cylinder. The maximum allowable cylinder wear (the
difference between these two measurements),is 0.008
inch.
(4) Replace the block if, it is cracked, or if
defects cannot be repaired. Replace loose or damaged
studs. Retap damaged threads. If a proper piston fit
cannot be attained, (para 4-10 c), the cylinders are
scratched or scored, or, cylinder wear exceeds 0.008
inch, rebore the cylinders as directed in d below.
(5) Inspect the backing plate for cracks and
distortion. Remove any burrs with a fine stone.
(6) Inspect the oil pressure relief valve for
scoring, wear, and other damage. Inspect the spring for
cracks and misalined coils. Replace damaged oil
pressure regulator parts.
d. Reboring. Rebore the cylinders to 3.4575to 3.4595-inch diameter (0.020 inch oversize). If this is
not sufficient to eliminate cylinder wear or damage,
rebore the cylinders to 3.4775- to 3.4795-inch diameter
(0.040 inch oversize). Maximum allowable overbore is
0.040 inch.
e. Reassembly and Installation.
(1) Reassembly and installation is the
reverse of removal and disassembly. Refer to figure 422.
(2) When installing the front end plate (22,
fig. 4-9), tighten the 5/16-inch bolts to 15 to 20 footpounds torque and tighten the 3 / 8-inch bolts to 25 to 30
foot-pounds torque.
(3) Install the camshaft (para 4-12c).
(4) Install the crankshaft and main bearings
(para 4-11c).
(5) Install the pistons and connecting rods
(para 4-10c).
(6) Install the flywheel and flywheel
housing (para 4-9c).
(7) Install the gear cover (para 4-8c).
(8) Install the oil pump (para 4-7c) and oil
pan (para 4-6c).
(9) Install the intake and exhaust valves
(para 4-4 d), and intake and exhaust manifolds (para
45c).
(10) Install the cylinder head (para 4-3c).
(11) See paragraph 3-13 for oil pressure
adjustment procedure.
KEY to fig. 4-22:
1.
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.
34.
35.
Oil gage rod
Oil gage rod support
Oil filler cap
Oil filler nipple
Nut
Gasket
Valve chamber cover
Gasket
Stud
Stud
Cap screw
Lock washer
Shoulder screw
Lock washer
Flywheel housing
Screw
Timing hole cover
Felt
Drive screw pointer
Housing plug
Lock washer
Ring dowel
Plug
Gasket
Relief valve spring
Pressure adjusting washer
Oil pressure relief valve
Ring dowel
Ring dowel
Oil header plug
Core hole plug
Core hole plug
Core hole plug
Baffle
Cylinder block
b.
Cleaning.
(1) Remove dirt and grease deposits from
the block with a putty knife. Steam-clean the block.
Remove greasy or gummy deposits with a cloth
dampened in cleaning solvent (FED. Spec. P-D-680).
Clean the oil and water passages in the block with
compressed air. Remove varnish deposits with a wire
brush.
(2) Clean the mounting plate and all other
parts with cleaning solvent (FED. Spec. P-D-680); dry
thoroughly.
c. Inspection.
(1) Inspect the block for cracks, damaged
sealing surfaces, scored or damaged bearing seats,
scored or scratched cylinder walls, damaged threads,
loose or damaged studs, corrosion in the water jacket, or
other defects.
(2) Check piston fit in the cylinder bores
(para 4-10c).
4-28
TM 5-4320-258-34
CHAPTER 5
REPAIR OF CENTRIFUGAL PUMP
and skid. Overhaul requires removal of the unit to a
workbench.
5-1.
General
This chapter covers repair and overhaul of the
centrifugal pump. Repair includes seal replacement and
check valve replacement.
Overhaul consists of
complete teardown to allow inspection and, if necessary,
replacement of all operating parts, including bearings,
impeller, and wear plate. Repair can be done without
removal of the entire pump assembly from the engine
5-2.
Check Valve Replacement
Replace the check valve as follows:
a. Remove the nuts (6, fig. 5-1) that secure
the suction flange (7) to the pump body; remove the
suction flange and gasket (8).
5-1
TM 5-4320-258-34
Figure 5-1. Suction and discharge assemblies, exploded view.
5-2
TM 5-4320-258-34
g. After assembly, operate the check valve by
hand to assure that it operates freely, and that it seats
firmly against the valve seat.
b. Remove the check valve seat (9) and the
check valve assembly consisting of the large weight
(13), small weight (14), and gasket (15). Remove the
screw (10), nut (11), and lock washer (12) to separate
the check valve parts.
c. Clean all parts with cleaning solvent (FED.
Spec. P-D-680); dry thoroughly.
d. Inspect the gasket for wear, cracks, tears,
and damaged seating surfaces. Replace a damaged
gasket.
e. Inspect the check valve seat for cracks and
for a damaged seating surface. Replace if damaged.
f.
Reassemble the parts by reversing the
removal procedure. Make sure the small weight is
assembled to face outward. Tighten the nuts evenly
and alternately in increments to prevent distortion of the
check valve gasket.
5-3.
Shaft Seal Replacement Replace
a. leaking shaft seal as follows: a. Remove
the tool box from the centrifugal pump assembly (TM 54320-258-12).
b. Remove the drain plug (1, fig. 5-1) and
drain all fluid from the pump body.
c. Use a hoist or other lifting device to
support the weight of the pump body (3, fig. 5-2).
Remove the bolts, nuts, and lock washers that secure
the feet of the pump body to the skid base.
5-3
TM 5-4320-258-34
Figure 5-2. Centrifugal pump, exploded view.
5-4
TM 5-4320-258-34
member (23). Remove the seal stationary member from the
seal plate.
Note: The seal members are not replaceable
individually. When replacing the seal, be sure to replace all
parts that are provided in the seal kit.
h.
Install the seal stationary member (23) in the
seal plate (24); install the seal plate on the bearing housing
(40) with nuts (21) and lock washers (22).
i.
Lubricate the inside diameter of the seal
rotating member (20). Install the rotating member on the
shaft, and install the seal spring (19). Take care to prevent
damage to the interior of the seal member during assembly or
premature failure will result. Also use extreme care to prevent
damage to the contact faces, both the stationary and rotating
seal members.
j.
When installing the impeller (15), be sure to
install the same thickness of shims (17 and 18) that was
removed.
k.
Reassemble the remainder of the pump by
reversing the disassembly procedure.
5-4.
Centrifugal Pump Overhaul
a.
Disassembly. Remove the pump from the
engine and skid (TM 5-4320-258-12). Disassemble in the
sequence indicated in figures 5-1 and 5-2. Note the following:
(1) Press the impeller shaft (39, fig. 5-2) and
bearings (36 and 38) from the bearing housing (40) as an
assembly.
(2) Remove the retaining rings (35 and 37) and
press the ball bearings (36 and 38) from-the shaft.
b.
Cleaning and Inspection.
(1) Discard and replace all seals, gaskets, and
packings.
(2) Clean the ball bearings as directed in
paragraph 2-7.
(3) Clean all remaining parts with cleaning
solvent (FED. Spec. P-D-680); wipe dry.
(4) Inspect the check valve seat for cracks,
chipped edges, and other damage; replace a damaged check
valve seat.
(5) Inspect the suction flange and discharge
elbow for distortion, cracks, and damaged connector grooves.
Remove nicks and burrs from the connector grooves with a
fine stone. Replace if damaged beyond repair.
(6) Inspect the pump body for cracks, loose or
damaged studs, and for damaged threads.
Clean up
damaged threads with a thread die. Replace any damaged
studs. Replace the housing if worn beyond repair.
(7) Inspect the wear plate for damage or wear.
If the wear is perceptible, replace the plate.
(8) Inspect the volute for cracks, distortion, and
wear. Replace if damaged.
(9) Inspect the impeller for cracked, chipped,
worn or broken vanes, damaged or distorted bore or keyway,
and other damage; replace a damaged impeller.
(10) Inspect the ball bearings for scored balls or
races,
cracked
races,
signs
of
overheating,
or
KEY to fig. 5-2:
1. Nut
2. Lock washer
3. Pump body
4. Stud
5. Volute gasket
6. Cap screw
7. Lock washer
8. Flat head screw
9. Nut
10. Lock washer
11. Wear plate
12. Volute
13. Lock nut
14. Impeller nut
15. Impeller
16. Woodruff key
17. Shim
18. Shim
19. Seal spring
20. Seal rotating member
21. Nut
22. Lock washer
23. Seal stationary member
24. Seal plate
25. Pipe plug
26. Coupling
27. Pipe nipple
28. Stud
29. Preformed packing
30. Cap screw
31. Lock washer
32. Bearing cap
33. Grease seal
34. Preformed packing
35. Retaining ring
36. Ball bearing
37. Retaining ring
38. Ball bearing
39. Impeller shaft
40. Bearing housing
41. Grease seal
d.
Remove the nuts (1) and lock washers (2) that
secure the pump body (3) to the bearing housing (40); slide
the pump body straight out to disengage it from the remainder
of the pump which is secured to the engine.
e.
Remove the cap screws (6) and lock washers
(7) that secure the assembled volute (12) and wear plate (11)
to the seal plate (24); remove the assembled parts.
f.
Remove the nuts (13 and 14) that secure the
impeller (15) to the impeller shaft (39). Pull the impeller from
the shaft and remove the key (16). Remove the shims (17
and 18), seal spring (19), and seal rotating member (20) from
the shaft.
g.
Remove the nuts (21) and lock washers (22)
that secure the seal plate (24) to the bearing housing (40);
remove the seal plate with the assembled seal stationary
5-5
TM 5-4320-258-34
the shaft lightly with oil and slide the seal rotating
member (20) in place on the shaft.
(5) If the same impeller (15) and wear plate
(11) are reassembled and no clearance change is
indicated, make sure that the same thickness of shims '
(17 and 18) is used. If a new impeller and / or wear
plate is to be installed, or if the impeller clearance is to
be changed, determine the shim thickness required to
obtain a clearance of 0.010 to 0.020 inch between the
impeller and wear plate as follows:
(a) Install impeller (15) on shaft (39)
without shims. Be sure that it is seated firmly against
the shaft shoulder.
(b) Install volute (12), with wear plate
( 11 ) assembled, and secure with screws (6) and lock
washers (7).
(c) Measure from the face of the
impeller (15) to the face of the wear plate ( 11) using a
feeler gage.
(d) Select shims (17 and 18) to equal
the dimension obtained less 0.010 to 0.020 inch for
clearance.
(6) After assembly, check the impeller
shaft for free rotation. It must turn freely without
catching or binding. If binding is evident, disassemble
and correct the condition upon reassembly.
(7) Install the pump on the engine and skid
(TM 5-4320-258-12).
rough, catching, or binding operation; replace damaged
bearings.
(11) Inspect the impeller shaft for distortion
and damaged retaining ring grooves, keyways, and
threads. Clean up damaged retaining ring grooves or
keyways with a fine stone. Repair damaged threads
with a thread chaser. Replace the shaft if it is damaged
beyond repair.
(12) Inspect the bearing housing for cracks,
distortion, or scored or burred bearing seats. Remove
nicks or burrs from the bearing seats with a fine stone.
Clean up damaged threads with a thread die. Replace a
damaged bearing housing.
c. Reassembly. Reassemble the pump by
reversing the disassembly sequence. Refer to figures 51 and 5-2. Note the following:
(1) Press bearings (36 and 38, fig. 5-2)
onto the impeller shaft (39). If bearings slide onto the
shaft by hand, they are too loose and the bearings and /
or shaft must be replaced. Secure bearings to the shaft
with retaining rings (35 and 37).
(2) Pack the bearings, bearing cap, and the
area between the bearings in the bearing housing with
MIL-G-10924 grease.
(3) Press grease seal (41) into the bearing
housing (40) and grease seal (33) into the bearing cap
(32) before installing the shaft and bearings in the
bearing housing.
(4) Press the seal stationary member (23)
into seal plate (24) before installing the plate. Lubricate
5-6
TM 5-4320-258-34
APPENDIX A
REFERENCES
A-1.
A-2.
Fire Protection
TB 5-4200-200-10
Lubrication
C9100-IL
LO 5-4320-258-12
A-3.
A-4.
A-5.
Painting Instructions for Field Use
Radio Suppression
TM 11-483
Radio Interference Suppression
Maintenance
Fed. Spec. P-D-680
TB 750-651
TM 5-4320-258-20P
TM 5-4320-258-34P
TM 9-6140-200-15
TM 5-764
TM 5-4320-258-12
Shipment and Storage
TB 740-93-2
TM 740-90-1
A-7.
Identification List for Fuels, Lubricants, Oils and
Waxes
Lubrication Order for Pump, Centrifugal, Barnes
Model US67CCG
Painting
TM 9-213
TM 38-750
TM 4320-258-34
A-6.
Hand Portable Fire Extinguishers Approved for
Army Users
Destruction of Army Materiel to Prevent
Enemy Use
TM 750-244-3
Dry Cleaning Metal Parts
Use of Antifreeze Solutions and Cleaning Compounds in Engine Cooling Systems
The Army Maintenance Management System
DS, GS, and Depot Maintenance Manual for
Pump, Centrifugal, Barnes Model US67CCG
Organizational Maintenance Repair Parts Manual
for Pump, Centrifugal, Barnes Model US67CCG
DS, GS, and Depot Maintenance Repair Parts List
for Pump, Centrifugal, Barnres Model US67CCG
Operation and Organizational Field and Depot
Maintenance Storage Batteries, Lead Acid Type
Electric Motor and Generator Repair
Operator and Organizational Maintenance Manual
for Pump, Centrifugal, Barnes Model US67CCG
Preservation of USAMEC Mechanical Equipment
for Shipment and Storage
Administrative Storage of Equipment
Procedures for Destruction of Equipment to
Prevent Enemy Use (Mobility Equipment
Command)
A-1
TM 5-4320-258-34
By Order of the Secretary of the Army:
Official:
W. C. WESTMORELAND,
General, United States Army,
Chief of Staff.
VERNE L. BOWERS,
Major General, United States Army,
The Adjutant General.
Distribution:
To be distributed in accordance with DA Form 12-25 (qty rqr Block No. 155), Direct/ General Support requirements for
Petroleum Distribution.
* U.S. GOVERNMENT PRINTING OFFICE: 1971-769-158/83
PIN: 008489-000
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