User manual | TM-5-4320-234-34

TM 5-4320-234-34
TECHNICAL MANUAL
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL
PUMP, CENTRIFUGAL, SELF-PRIMING,
GASOLINE ENGINE DRIVEN, WHEEL MOUNTED,
6-INCH, 1500 GPM CAPACITY AT 60 FOOT HEAD
(PEABODY BARNES, INC. MODEL US90CCG-1)
NSN 4320-00-490-1859
HEADQUARTERS, DEPARTMENT OF THE ARMY
AUGUST 1975
TM 5-4320-234-34
WARNING
POISONOUS GASES
are contained in the exhaust fumes expelled by this equipment.
DEATH
or serious illness may result if exhaust fumes are not properly expelled from enclosed areas.
FLAMMABLE GAS
is generated in the battery of this equipment while the battery is being charged. Keep fire or flame away while
servicing battery or explosion may result.
FIRE HAZARD
is created by filling fuel tank while engine is running. Shut off engine before servicing fuel tank.
EXPLOSION HAZARD
exists when welding repairs are attempted on fuel tank.
DEATH
may result unless all gasoline fumes are purged from tank before making any repairs involving heat or flame.
SEVERE INJURY
may result from contact with the rotating cooling fan. When it is necessary to make governor adjustments or
any other adjustments in the fan area, remove the cooling fan drive belt before making the adjustment.
HEALTH AND SAFETY HAZARD
exists when cleaning solvents are used. Clean all parts in a well ventilated area. Avoid inhalation of solvent
fumes and prolonged exposure of skin to cleaning solvent. Wash exposed skin thoroughly. Dry cleaning
solvent (Fed. Spec. P-D-680) used to clean parts is potentially dangerous to personnel and property. Do not use
near open flame or excessive heat. Flash point of solvent is 100F. to 138F. (38 C to 59 C).
TM 5-4320-234-34
Technical Manual
No. 5-4320-234-34
}
HEADQUARTERS
DEPARTMENT OF THE ARMY
Washington, D.C., 29 August 1975
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL
PUMP, CENTRIFUGAL, SELF-PRIMING,
GASOLINE ENGINE DRIVEN, WHEEL MOUNTED,
6-INCH, 1500 GPM CAPACITY AT 60 FOOT HEAD
(PEABODY BARNES, INC. MODEL US9OCCG-1)
NSN 4320-00-490-1859
___________
Paragraph
Chapter
Section
Chapter
Section
Chapter
Section
Chapter
Section
Chapter
Chapter
Appendix
Index
1.
I.
II.
2.
I.
II.
III.
IV.
3.
I.
II.
III.
IV.
V.
VI.
4.
I.
II.
5.
6.
A.
Page
INTRODUCTION
General ........................................................................................................................ 1-1
1-1
Description and data .................................................................................................... 1-7
1-1
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE INSTRUCTIONS
Repair parts, special tools, and equipment.................................................................... 2-1
2-1
Troubleshooting ........................................................................................................... 2-3
2-1
General maintenance ................................................................................................... 2-5
2-28
Removal and installation of major components and assemblies ................................... 2-9
2-29
REPAIR OF ENGINE COMPONENTS
General......................................................................................................................... 3-1
3-1
Repair of governor ....................................................................................................... 3-3
3-1
Repair of radiator ......................................................................................................... 3-7
3-4
Repair of oil system components ................................................................................. 3-13
3-4
Repair of electrical system components ....................................................................... 3-16
3-8
Repair of engine mounting ............................................................................................ 3-21 3-20
REPAIR OF ENGINE
Introduction .................................................................................................................. 4-1
4-1
Engine repair and overhaul .......................................................................................... 4-3
4-3
REPAIR OF CENTRIFUGAL PUMP ASSEMBLY........................................................................ 5-1
REPAIR OF CHASSIS................................................................................................................ 6-1
REFERENCES ...........................................................................................................................A-1
.................................................................................................................................................... I-1
i
TM 5-4320-234-34
LIST OF ILLUSTRATIONS
Figure
1-1
1-2
1-3
2-1
2-2
2-3
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
2-20
2-21
2-22
2-23
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
3-17
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
Title
Page
Centrifugal pump, left rear view ................................................................................................................1-2
Centrifugal pump, right front view .............................................................................................................1-3
Data plates ................................................................................................................................................1-4
Cylinder head ............................................................................................................................................2-2
Cylinder head capscrew tightening sequence ............................................................................................2-3
Compression test (sheet 1 of 2) ................................................................................................................2-4
Compression test (sheet 2 of 2) ................................................................................................................2-5
Valve adjustment.......................................................................................................................................2-6
Radiator removal .......................................................................................................................................2-2
Oil pressure adjustment ............................................................................................................................2-9
Magneto and governor installation ............................................................................................................2-10
Carburetor removal ...................................................................................................................................2-11
Magneto removal ......................................................................................................................................2-12
Governor removal ....................................................................................................................................2-13
Engine timing marks ..................................................................................................................................2-14
Engine timing mark pointer .......................................................................................................................2-15
Magneto to spark plug connections............................................................................................................2-16
Centrifugal pump removal and installation ................................................................................................2-17
Centrifugal pump disassembly and reassembly ........................................................................................2-19
Centrifugal pump removal and installation ................................................................................................2-21
Centrifugal pump disassembly and reassembly ........................................................................................2-23
Centrifugal pump removal and installation ................................................................................................2-25
Pump coupling ..........................................................................................................................................2-26
Bearing housing ........................................................................................................................................2-27
Centrifugal pump, removal and installation ...............................................................................................2-30
Pump coupling, exploded view .................................................................................................................2-32
Engine, removal and installation ...............................................................................................................2-34
Operation of engine speed regulating system ...........................................................................................3-2
Governor removal, exploded view ............................................................................................................3-3
Timing marks on governor drive gear and cam gear .................................................................................3-4
Engine oil filter mounting, exploded view ..................................................................................................3-6
Oil filter assembly, exploded view .............................................................................................................3-7
Oil pressure adjustment ............................................................................................................................3-8
Alternator assembly, exploded view ..........................................................................................................3-9
Alternator brush assembly, showing continuity paths .................................................................................3-10
Stator winding and connections ................................................................................................................3-12
Stator test points .......................................................................................................................................3-13
Alternator bench test circuit .......................................................................................................................3-14
Voltage regulator adjustment circuit ..........................................................................................................3-15
Circuit for checking pinion clearance ........................................................................................................3-16
Checking pinion clearance ........................................................................................................................3-17
Starting motor, exploded view ..................................................................................................................3-17
Starting motor no-load test setup ..............................................................................................................3-18
Engine mounting parts, exploded view ......................................................................................................3-20
Cylinder head, exploded view4 ..................................................................................................................4-4
Cylinder head capscrew tightening sequence ............................................................................................4-5
Valves and camshaft, exploded view ........................................................................................................4-6
Valve guide installation dimensions ...........................................................................................................4-7
Narrowing valve seat ................................................................................................................................4-8
Oil pan and filler blocks, exploded view ....................................................................................................4-9
Engine oil pump installation ......................................................................................................................4-10
Gear cover and front end plate, exploded view ..........................................................................................4-11
Checking flywheel runout ..........................................................................................................................4-12
Checking flywheel eccentricity ...................................................................................................................4-12
Checking flywheel housing runout..............................................................................................................4-13
iii
TM 5-4320-234-34
Figure
4-12
4-13
4-14
4-15
4-16
4-17
4-18
4-19
4-20
4-21
5-1
5-2
6-1
6-2
Title
Page
Checking flywheel housing eccentricity .....................................................................................................4-13
Piston, crankshaft, and flywheel, exploded view .......................................................................................4-14
Checking piston fit in cylinder bore ............................................................................................................4-15
Removing upper bearing shell with angular pin..........................................................................................4-17
Checking bearing clearance with plastigage ..............................................................................................4-18
Installing upper bearing half, using angular pin ..........................................................................................4-18
Checking bearing clearance with shim stock .............................................................................................4-18
Timing gears showing alinement marks ....................................................................................................4-19
Checking for insufficient timing gear clearance..........................................................................................4-20
Cylinder block and flywheel housing, exploded view ..................................................................................4-21
Centrifugal pump, exploded view...............................................................................................................5-2
Bearing housing, exploded view ...............................................................................................................5-4
Axle and suspension system, exploded view .............................................................................................6-2
Chassis frame, exploded view ...................................................................................................................6-4
iv
TM 5-4320-234-34
CHAPTER 1
INTRODUCTION
Section I. GENERAL
a. Priority for Destruction. When lack of time or
personnel prevents complete destruction of the
equipment, the following priority will be used in
demolition of essential parts.
1-1. Scope
This manual is for your use while providing direct
support and general support maintenance of the Pump,
Centrifugal, Self-priming, Gasoline Engine Driven,
Wheel Mounted, 6-Inch, 1500 GPM Capacity at 60 Foot
Head (Peabody Barnes, Inc. Model US9OCCG-1).
(1) Using an axe, pick, mattock, sledge, or
any other heavy implement, damage all vital elements
such as controls, water, or fuel pumps, cooling systems,
switches, and any other major assemblies or
components.
1-2. Maintenance Forms and Records
Maintenance forms, records, and reports that you
are required to use are DA Form 2400, 2401, 2402,
2404 and 314 (see TM 38-750).
(2) Place 1/2 pound (0.22 kg) charges on
the following for demolition with explosives.
1-3. Reporting of Errors
(a) Charge located at carburetor,
governor, fuel pump and flywheel area.
You can help to improve this manual by calling
attention to errors and by recommending improvements.
Your letter, DA Form 2028 (Recommended Changes to
Publications), or DA Form 2028-2 (Recommended
Changes to Equipment Technical Manuals), may be
used. Copies of DA Form 2028-2 are attached in the
back of the manual for your use. Please mail your
recommended changes directly to Commander, U. S.
Army Troop Support Command, ATTN: AMSTS-MPP,
4300 Goodfellow Blvd, St. Louis, MO 63120. A reply
will be furnished directly to you.
(b) Charge located at cylinder head
and crankcase.
(c) Charge located at intake and
exhaust manifold.
(3) Demolition by misuse. Add sand to oil in
engine and drop nuts and bolts into pump case. Run
engine until pump fails.
(4) Demolition by burning.
Pack rags,
clothing, or canvas under or around the engine and
pump. Saturate this packing with gasoline, oil, or diesel
fuel and ignite.
1-4. Equipment Serviceability Criteria
This equipment is not covered by an ESC.
1-6. Administrative Storage
1-5. Destruction of Army Material to Prevent Enemy
Use
Prepare the pumping assembly for storage
according to procedures given in TM 740-90-1.
Section II. DESCRIPTION AND DATA
pump mounted on a two-wheel chassis. The torque
from the engine is transferred to the pump through an
intermediate shaft and flexible coupling.
1-7. Description
a.
Centrifugal Pump, Model US90CCG-1,
consists primarily of a gasoline engine and a centrifugal
1-1
TM 5-4320-234-34
Figure 1-1. Centrifugal pump, left rear view.
1-2
TM 5-4320-234-34
Figure 1-2. Centrifugal pump, right front view.
b. The centrifugal pump has a 6-inch suction
flange secured to the front of the pump body, and a
6inch discharge elbow secured to the top of the pump
body. The bearing housing (13, 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 a locking cone. The impeller is
inclosed in a close fitting volute to provide efficient
pumping operation. A replaceable wear plate at the
front of the impeller is subjected to most of the internal
pump wear.
maximum speed. The engine is inclosed 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 restore the charge of the battery as it 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. The fan also maintains
a flow of air around the engine to provide proper
cooling.
d. The engine and pump are secured to a twowheeled chassis. The chassis consists primarily of hub
assemblies, pneumatic tires, welded frame, and axle.
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 over-speed governor that shuts off
the engine when the engine speed reaches a : preset
e. You will find detailed descriptions of centrifugal
pump components in the repair paragraphs of this
manual.
1-3
TM 5-4320-234-34
1-8. Differences Between Models
shipping information.
This technical manual covers only Centrifugal
Pump, Peabody Barnes Model US9OCCG-1. No known
differences exist for this model number.
(2) Engine data plate. The engine data
plate (B, fig. 1-3) is located on alternator side of the
engine block. It indicates engine identification numbers,
serial number, valve tappet clearance information, and
patent information.
1-9. Tabulated Data
(3) Instruction plate. The pump instruction
plate (C, fig. 1-3) is located in the cover of the control
panel. It identifies the controls and provides basic
operating instructions.
a. Identification. The pumping assembly has
three identification plates, as follows:
(1) Pump data plate. The pump data plate
(A, fig. 1-3) is located on front of the pump above the
suction flange. It indicates the pump identification
number,
serial number, dimensions, weight, and
Figure 1-3. Data plates.
b. Tabulated Data. Tabulated data applicable to
the centrifugal pump and its components is given in
table 1-1.
Table 1-1. Tabulated Data
Manufacturer...........................................................................................................................Peabody Barnes, Inc.
Model number .........................................................................................................................US9CCG-1
Serial number range ...............................................................................................................56751-001 thru 56751-024
Type .......................................................................................................................................Self-priming, centrifugal
Output (at maximum rated speed) ..........................................................................................1500 gpm at 60 feet head
Rated driven speed ................................................................................................................2450 rpm
1-4
TM 5-4320-234-34
Table 1-1. Tabulated Data - Continued
Suction port size .............................................................................................................. 6 in., No. 6-8 NPT
Discharge port size........................................................................................................... 6 in., No. 6-8 NPT
Engine
Manufacturer ............................................................................................................ Continental Motors Corp.
Model ........................................................................................................................ FS244-6100P
Type .......................................................................................................................... Four stroke cycle
Number of cylinders................................................................................................... 6
Displacement ............................................................................................................ 244 cu in.
Compression ratio...................................................................................................... 6.9:1
Coolant ..................................................................................................................... Water
Cooling system capacity ........................................................................................... 18 qt (17.10 L)
Crankcase oil capacity ............................................................................................... 5-1/2 qt (5.22 L)
Valve clearance (warm)
Intake .................................................................................................................... 0.014 in. (0.035 cm)
Exhaust ................................................................................................................. 0.016 in. (0.040 cm)
Spark plug gap .......................................................................................................... 0.025 in. (0.063 cm)
Breaker point gap ...................................................................................................... 0.015 in. (0.037 cm)
Firing order ............................................................................................................... 1-5-3-6-2-4
Governed speed ........................................................................................................ 2450 rpm
Overspeed cutout ..................................................................................................... 2700 rpm
Alternator
Manufacturer ............................................................................................................ Motorola
Part number .............................................................................................................. MA24-900G
Voltage ..................................................................................................................... 24
Amperage output ...................................................................................................... 35
Voltage regulator
Manufacturer ............................................................................................................ Motorola
Part number .............................................................................................................. 70C44707B
Starting motor
Manufacturer ............................................................................................................ Delco-Remy
Part number .............................................................................................................. 1108271
Voltage ..................................................................................................................... 24
Magneto
Manufacturer ............................................................................................................ Fairbanks-Morse
Part number .............................................................................................................. FMZE6B16P
Fuel pump
Manufacturer ............................................................................................................ AC Spark Plug
Part number .............................................................................................................. 6440314
Carburetor
Manufacturer ............................................................................................................. Zenith
Part number .............................................................................................................. 12334
Air cleaner
Manufacturer ............................................................................................................ Donaldson
Part number .............................................................................................................. FWG06-66032
Oil filter
Manufacturer ............................................................................................................ Fram
Part number .............................................................................................................. C7407
Military standard number ........................................................................................... MS35343-1
Overall dimensions and weight
Overall length ........................................................................................................... 119 in. (297.5 cm)
Overall width ............................................................................................................. 68.5 in. (171.2 cm)
Overall height ........................................................................................................... 71 in. (177.5 cm)
Overall weight ........................................................................................................... 2630 lbs (1183.5 kg)
Shipping weight ........................................................................................................ 2630 lbs (1183.5 kg)
Shipping volume ....................................................................................................... 343 cu ft
Ground clearance ...................................................................................................... 13.25 in. (33.12 cm)
Engine torque specifications
1-5
TM 5-4320-234-34
Table I-I. Tabulated Data - Continued
Torque (ft-lb)
Cylinder head capscrews .......................................................................................... 35 to 40 (4.84 to 5.53 kgm)
Main bearing capscrews ............................................................................................ 85 to 95 (11.75 to 13.13 kgm)
Connecting rod nuts .................................................................................................. 40 to 45 (5.53 to 6.22 kgm)
Flywheel nuts ............................................................................................................ 35 to 40 (4.84 to 5.53 kgm)
Manifold nuts ............................................................................................................ 25 to 30 (3.45 to 4.14 kgm)
Gear cover bolts and nuts
3/8 in ..................................................................................................................... 25 to 30 (3.45 to 4.14 kgm)
7/16 in ................................................................................................................... 50 to 55 (6.91 to 7.60 kgm)
Oil pan bolts .............................................................................................................. 12 to 16 (1.65 to 2.21 kgm)
Flywheel housing bolts............................................................................................... 50 to 55 (6.91 to 7.60 kgm)
Filler block bolts ........................................................................................................ 15 to 20 (2.07 to 2.76 kgm)
Front end plate bolts
3/8 in. ..................................................................................................................... 25 to 30 (3.45 to 4.14 kgm)
7/16 in ................................................................................................................... 50 to 55 (6.91 to 7.60 kgm)
Camshaft thrust plate bolts ....................................................................................... 15 to 20 (2.07 to 2.76 kgm)
Water pump bolts ..................................................................................................... 25 to 30 (3.45 to 4.14 kgm)
Magneto bolts ............................................................................................................ 25 to 30 (3.45 to 4.14 kgm)
Governor bolts .......................................................................................................... 25 to 30 (3.45 to 4.14 kgm)
1-6
TM 5-4320-234-34
CHAPTER 2
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
INSTRUCTIONS
Section I. REPAIR PARTS, SPECIAL TOOLS, AND EQUIPMENT
Repair parts and equipment are listed and
illustrated in the repair parts and special tools list
covering direct support and general support
maintenance for this centrifugal pump. Refer to TM
54320-234-34P when you need replacement parts
information.
2-1. Special Tools and Equipment
No special tools or equipment is required for the
repair and maintenance of the pumping assembly.
2-2. Maintenance Repair Parts
Section II. TROUBLESHOOTING
the scope of direct and general support maintenance are
listed. For troubleshooting procedures which are within
the scope of operator/crew and organizational
maintenance, you should refer to TM 5-4320-234-12.
2-3. General
a.
This section contains troubleshooting
information for locating and correcting most of the
operating troubles which may develop in the pumping
assembly.
Each malfunction for an individual
component, unit, or system is followed by a list of tests
or inspections which will help you to determine probable
causes and corrective actions to take. You should
perform the tests/inspections and corrective actions in
the order listed.
2-4.
Direct Support and
Maintenance Troubleshooting
General
Support
Refer to table 2-1 for troubleshooting which is
allocated to direct support and general support
maintenance levels.
b. This manual cannot list all malfunctions that
may occur, nor all tests or inspections, or corrective
actions. If you experience a malfunction which is not
listed or is not remedied by listed corrective actions,
notify your supervisor.
NOTE
Before you use the troubleshooting
table, be sure you have performed all
applicable operating checks.
c. Only those functions which are solely within
Table 2-1. Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE
1. LOW OR UNEVEN COMPRESSION
Step 1. Check for damaged cylinder head gasket or loose cylinder head by listening for hissing noise on compression stroke.
Replace head gasket or tighten cylinder head bolts to proper torque.
(1) Remove the cylinder head and gasket as shown in figure 2-1. When removing the cylinder head screws, loosen each a
small increment until all are started. This will help prevent cylinder head distortion.
2-1
TM 5-4320-234-34
Figure 2-1. Cylinder head.
2-2
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
(2) Using a new head gasket, install cylinder head as shown in figure 2-1.
Tighten the cylinder head screws according to the sequence shown in figure 2-2. Torque to 35 to 40 foot-pounds (4.84 to
5.53 kgm).
Figure 2-2. Cylinder head capscrew tightening sequence
Step 2.
Check for bad piston rings or burned or warped valves.
a. Follow step-by step procedures listed on figure 2-3 and perform compression test.
2-3
TM 5-4320-234-34
BATTERY FULLY
CHARGED?
ALL PARTS A-OK?
CRANKCASE OIL
SHIFT IN
NEUTRAL IF
APPLICABLE
SET
PARKING
BRAKE IF
APPLICABLE
LEVEL OK?
NORMAL READING
IGNITION “ON”ONLY.
FSN 4910-250-2423
RUN ENGINE
BRING TO
OPERATING TEMP.
LOW BATTERIES WILL
NOT TURN OVER ENGINE
AT MAXIMUM RPM
6
IGNITION OFF ON
TACTICAL VEHICLES
REMOVE COIL
CABLE ON
COMMERCIAL
VEHICLES
THROTTLE - OUT
SPARK PLUGS
LOOSEN - BLOW OUT
STEP
1.
ADAPTER - HOSE
REMOVE - CLEAN HOLES
CHOKE - IN
STEP
2.
SCREW IN NO. 1
CYLINDER...
FINGER TIGHT
TS 011524
Figure 2-3. Compression test.
2-4
TM 5-4320-234-34
WITH GAGE ATTACHED
TO NO. 1 CYLINDER....
HAVE HELPER
TURN OVER ENGINE
ABOUT 10 REVS.
DO ALL OTHER
CYLINDERS THE SAME.
****
ZERO GAGE AND CLEAN TIP
AFTER EACH CYLINDER TEST.
****
SAMPLE READING
CYL
PSI
DON’T OVERHEAT
STARTER
1
115
2
125
3
120
4
100
5
125
6
115
CAUSE & CURE:
LOOK FOR SIGNS OF LEAKAGE. IF ANY, REPLACE GSKET IF MAC SAYS SO.
WET TEST EACH CYLINDER. DO THE SAME FOR A DRY TEST. BUT BEFORE
SCREWING IN THE GAGE, SQUIRT A LITTLE OIL ON THE CYLINDER WALL—
ALL AROUND. IF THE PSI GOES TO ALLOWABLE MINIMUMS (STEP 15) OR ABOVE,
THE RINGS ARE BAD. NOTIFY YOUR NEXT HIGHER LEVEL OF MAINTENANCE.
3. BAD OR MISADJUSTED VALVES
OVERHEAD
FLATHEAD TYPE
2-5
IF WET TEST DID NOT IMPROVE READINGS ADJUST VALVE
CLEARANCES. IF COMPRESSION IS STILL BAD, REFER TO
NEXT HIGHER LEVEL OF MAINTENANCE...PRE YOUR MAC
CHART.
IF WET TEST DID NOT IMPROVE READINGS AND GASKET
IS OK, NOTIFY NEXT HIGHER LEVEL OF MAINTENANCE.
TS 011524
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
b. If test indicates compression is low, report to next higher level of maintenance.
Step 3. Check for improperly adjusted valve tappets.
a. Operate engine until it reaches operating temperature.
b. Disconnect the positive crankcase ventilation valve and fittings from the valve cover.
c. Remove the nuts and washers that secure the valve chamber cover to the cylinder block. Remove the valve chamber cover and
gasket.
d. With the engine running at operating temperature and at idle speed, check the valves for proper clearance. Intake valves should
be set for 0.014 inch (0.035 cm) clearance and exhaust valves 0.016 inch (0.04 cm) clearance.
(1) Alternately pass a 0.013 inch (0.032 cm) and 0.015 inch (0.037 cm) flat feeler gage between the head of the intake valve
adjusting screw of the tappet (13, fig. 2-4), and stem of valve (2 fig 2-4).
Figure 2-4. Valve adjustment.
2-6
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
(2) If a 0.013 inch (0.032 cm) feeler gage moves back and forth in gap when the valve is not being lifted, and a 0.015 inch (0.037 cm) feeler gage
binds at all times, the clearance requires no adjustment.
(3) Check the exhaust valve clearance in the manner described above, using 0.015 (0.37 cm) and 0.017 inch (0.042 cm) feeler gages
.
(4) If a 0.013 (0.032 cm) or 0.015 inch (0.037 cm) feeler gage is gripped at all times, the clearance is insufficient.
Adjust valves as follows:
(1) 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 cheek and adjustment until you obtain the proper clearance. The adjustable type valve lifters have
self-locking adjusting screws that require no lock nuts.
(2) Install valve chamber cover and gasket Se
cure valve chamber cover to cylinder block with nuts and washers.
(3) Install positive crankcase ventilation valve and fittings in valve chamber cover.
2. WATER TEMPERATURE SAFETY SWITCH STOPS ENGINE OPERATION
Step 1. Test the radiator for leaks.
a. Remove the radiator from the unit.
(1) Drain the radiator and oil cooler and remove the coolant and oil cooler lines from the radiator.
(2) Remove the engine housing as necessary to provide access to the radiator for removal.
(3) Remove screws (1, fig. 2-5), fiatwashers (2), and fan guard (3). Remove screws (4), lockwashers (5) and remove supports (6
and 7). Remove screws (8), lockwashers (9), fiat washers (10), and fan shroud (11).
2-7
TM 5-4320-234-34
Figure 2-5. Radiator removal.
2-8
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
(4) Use a rope sling and a hoist to support the weight of the radiator before removing nuts (12), lockwashers (13), that secure the radiator to the
engine supports Remove nuts (12), lockwashers (13), and remove radiator (14) and liners (15).
b. Inspect all parts for cracks, leaking tubes or gasket.
CAUTION
Do not exceed 10 psi air pressure for radiator testing. Excess pressure will
damage the radiator. Make sure that you completely drain the radiator core 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 leaks could remain
undetected.
c. Make sure the radiator is completely drained of coolant. Plug all openings, except one through which compressed air can he applied. Immerse
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 leak. If leaks
are found, mark the areas for repairs.
Repair radiator.
(1) Repair leaks by soldering. Be sure that you o
d not block or retard circulation through any tubes. There shall be no
blocked tubes upon completion of repairs.
(2) Use a rope sling and a hoist and install lines (15, fig. 2-5), and radiator (14). Secure radiator to engine supports with
lockwashers (13) and nuts (12).
(3) Install fan shroud (11), and secure with flatwasher (10), lockwashers (9), and screws (8). Install supports (7 and 9) and
secure with lock-washers (5) and screws (4). Install fan guard (3) and secure with flatwashers (2) and screw (1).
(4) Install engine housing and oil cooler and coolant on the radiator. Service the engine coolant system.
3. OIL PRESSURE SAFETY SWITCH STOPS ENGINE OPERATION
Step 1. Check for improperly adjusted oil pressure regulator valve.
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.
If the engine oil pressure is not within the required range, shut off the engine and adjust the oil pressure regulator valve.
(1) Remove plug (1, fig. 2-6) and gasket (2) from the carburetor side of the engine. Remove the valve spring (3) and
pressure adjusting washers (4).
1.
2.
3.
4.
Plug
Gasket
Valve spring
Washer
Figure 2-6. Oil pressure adjustment
2-9
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
(2) To increase oil pressure, add a washer between spring and oil pressure regulator valve. More than four washers should not be
used. If four washers do not fulfill the required range, either the spring is faulty or other engine troubles exist.
(3) After you make the adjustments, check that the oil pressure remains In the required ranges during operation.
4. ENGINE LOCKS POWER, SMOKES, OR OPERATES ERRATICALLY
Step I. Check for incorrect engine timing
.
With the engine running at 600 rpm, use a timing light connected to the rear spark plug and check that the IGN-M indication on the fiywheel is alined
with the timing pointer.
If timing pointer and IGN-M indication on the flywheel are not aligned, the engine timing must be adjusted.
Loosen the magneto mounting hardware slightly and rotate the magneto slightly until the correct indication Is attained. Tighten the magneto
mounting hardware firmly.
6. ENGINE SPEED VARIES OR ENGINE SURGES
Check for a defective governor.
a. Start the engine and allow it to warm to operating temperature. While it is warming up, back out the surge adjusting screw (1, fig. 2-7) so that it
will not influence the governor setting.
1.
2.
8.
4.
5.
6.
7.
Surge adjusting screw
Speed adjusting screw
Speed adjusting lockscrew
Sensitivity adjusting
Throttle rod
Nut
Ball joint
Figure 2-7. Governor adjustment.
b. With the engine warmed up and with the pump not under load adjust the engine idle speed to approximately 150 rpm higher than the required idle
speed under load. Make this adjustment by turning the adjusting screw (2, fig. 2-7). Back out speed adjusting lockscrew (3) so that it will not
influence the adjustment.
c. The governor's range of action is the differential between the engine speed under load and the engine speed without load. To broaden the range
of action use the sensitivity adjusting screw (4). Lengthen the Sensitivity adjusting screw to broaden the range of action of the engine. To
narrow the range of action, shorten the sensitivity adjusting screw (4) and compensate for seed change with the speed adjusting screw (3).
2-10
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
d. When the governor range of action is properly adjusted, allow the engine to run at governed seed, no load, and check for surging. If surging is
noted, turn in the surge adjusting screw (1) just far enough to eliminate the surging.
e. The surge adjustment can also be made by using the tachometer. With the engine running at governed speed, no load, turn in the surge
adjusting screw (1) until the engine speed increases 10 to 20 rpm and tighten the lock nut. If the carburetor and linkage are properly adjusted,
surge will disappear
f. If the governor cannot operate the throttle lever on the carburetor through the full operator range, it will be necessary to adjust the length of the
throttle rod (5) by loosening the nut (6) and adjusting the position of the ball joint (7).
g. When the governor adjustment is completed, tighten the speed adjusting lockscrew (2) to lock the cam in position. Make sure all locking nuts
are tightened.
If the governor cannot be adjusted, replace it.
(1) Disconnect the ball joint on governor to carburetor control rod from the lever on the governor.
(2) Disconnect fuel hoses (1 and 2, fig. 2-8) from the carburetor. Remove
air cleaner hose (3) from the carburetor.
1.
2.
3.
4.
5.
6.
7.
8.
Fuel hose
Fuel hose
Air cleaner hose
Throttle control cable
Choke control
Nut
Lockwasher
Carburetor
Figure 2-8. Carburetor removal.
(3) Disconnect the ends of the throttle control cable (4) and choke control (5) from their respective levers on the carburetor.
(4) Remove nuts (6), lockwashers (7), and remove carburetor (8).
(5) Remove four screws (1, fig. 2-9) and lockwashers (2) that secure the cover (3) on the magneto; remove the cover and
gasket (4).
2-11
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
1.
2.
3.
4.
5.
Screws
Lockwasher
Cover
Gasket
Screw
5.
7.
8.
9.
10.
Lockwasher
Flatwasher
Ground lead
Bolt
Flatwasher
11.
12.
13.
14.
15.
Gasket plate
Gasket
Magneto
Gasket
Spacer
Figure 2-9. Magneto removal.
(6) Disconnect the shielded spark plug cables from the magneto end cap by unscrewing the shield connectors. Disconnect
the ends of the leads from the distributor cap in the magneto end cap.
(7) Remove the lower screw (5), lockwashers (6), and flatwasher (7) that secure the bottom of the magneto and ground lead
(8) to the engine front end plate. Remove bolt (9), flatwasher (10), gasket plate (11), and gasket (12) that secure the top
of the magneto and governor to the gear cover; remove magneto (13), gaskets (14) and spacer (15).
(8) Remove screw (1, fig. 2-10). governor (2) and gasket (3).
2-12
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
Figure 2-10. Governor removal.
(9) Install gasket (3, fig. 2-10) and governor (2) on gear cover. Sight through the magne
to mounting hole to check that the
two marked teeth of the governor drive gear engage the single marked tooth of the cam gear as shown in figure 2-11.
Ignitor timing is dependent upon this relationship because the magneto is driven by the governor drive gear. Install
gasket (12, fig. 2-9), gasket plate (11), flatwasher (10) and bolt (9). Tighten the mounting bolt moderately.
2-13
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
Figure 2.11. Engine timing marks.
(10) Remove the rear spark plug from the engine. Put your thumb over the spark plug hole and crank the engine until no. 6
cylinder starts on the compression stroke. This is indicated by air being compressed against your thumb as the piston
rises In the cylinder.
(11) Set the piston on top-dead center by slowly cranking until the DC mark on the flywheel {2, fig.
2-12), visible through the
timing hole (1) In the housing, is aligned with the timing mark pointer. Hold the engine at this setting.
2-14
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
Figure 2-12. Engine timing mark pointer.
(12) Mount the magneto In a vise thoroughly lined with soft cloths. Insert a spark plug cable intoistributor
d
block hole for
spark plug no. 6. Refer to figure 2-13. Turn the drive lugs clockwise while holding the high tension cable for no. 6
cylinder close to the magneto frame so that a spark will are when the no. 6 cable is energized. When no. 6 cable arcs,
the magneto is at the no.6 firing position. Hold the magneto drive shaft at this position.
2-15
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
Figure 2-13. Magneto-to-spark plug connections.
(13) Remove the magneto from the vise. Turn the magneto drive lugs of the impulse coupling counterclockwise about one
quarter turn so that the lugs will mash with the drive members of the governor drive gear. Position the magneto (13 fig.
9) gaskets (14) and spacer (14), on the engine with the magneto lugs engaged. Install screw (5), lockwashers (6),
flatwasher (7) and ground lead (8). Tighten mounting screw modestly. Install and connect the spark plug cables to the
magneto end cap.
(14) Start the engine and idle at 600 rpm. If the engine fails to start, it is probably due to faulty ignition, timing. Recheck
timing as directed in paragraph (9).
(15) With the engine running at 600 rpm, use a timing light connected to the rear spark plug and check that the IGN-M
indication on the flywheel is aligned with the timing pointer. If it is not exactly alined, loosen the magneto mounting
hardware slightly and rotate the magneto slightly until the correct Indication is attained. Tighten the mounting hardware
firmly..
(16) Refer to Step 1, para a through g and adjust the governor.
6. PUMP RUNS WITH NO DISCHARGE OR WITH LOW PRESSURE
Step 1. Check for a broken, worn, or damaged impeller.
a. Use a hoist or other lifting devices to support the weight of the pump (1, fig. 2-14). Remove nuts (2), lockwashers (3) and screws
(4) that secure the pump to the chassis frame.
2-16
TM 5-4320-234-34
1. Pump
3. Lockwasher
2. Nut
4. Screw
Figure 2-14. Centrifugal pump removal and installation.
2-17
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE CONTINUED
b. Remove nuts and lockwashers that secure pump body to the bearing housing;: slide the pump body straight out to disengage it from the
remainder of the pump which is secured to the engine.
e. Disassemble the pump following the sequence of index numbers in figure 2-15.
2-18
TM 5-4320-234-34
Figure 2-15. Centrifugal pump disassembly and reassembly.
2-19
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CENTRIFUGAL PUMP CONTINUED
d. Inspect the impeller for cracked, chipped, worn or broken vanes, damaged oristorted
d
bore or keyway.
Replace a damaged impeller.
(1) Reassemble the pump by reversing the disassembly sequence in figure 2-15. Note the following.
a. Press the seal stationary member (26) into seal plate (29) before installing the plate. Lubricate the impeller shaft lightly
with oil and slide the seal rotating member (25) and spring into place on the shaft
b. If the same impeller (20) and wear plate (17) are reassembled and no clearance change is indicated, use shims (22 and
23) of the same thickness as those removed. If a new impeller and/or wear plate is installed, determine the shim
thickness required to obtain a clearance of 0.010 to 0.020 inch (0.025 to 0.05 cm) between the impeller and wear plate as
follows:
c. Install impeller (20) on shaft without shims. Be sure that Impeller is seated firmly against the shaft shoulder.
d. Install volute (18) with wear plate (17) assembled, and secure with screws (12) and lockwashers (13).
e. Insert a feeler gage into the front openin
g of the volute and measure from the face of the impeller (20) to the face of the
wear plate (17)
f. Select shims (22 and 23) to equal the dimension obtained less 0.010 to 0.020 inch (0.025 to 0.05 cm) clearance.
(2) After reassembly, when using either new or used parts, recheck the clearance; it must be 0.010 to 0.020 Inch (0.025 to 0.05 cm).
Check the impeller shaft for free rotation. It must turn freely without catching or binding. If binding is evident, disassemble the
pump and correct the condition.
(3) Use a hoist or other lifting device and install the pump on the chassis. Install nuts and lockwashers that secure the pump body to
the bearing housing.
(4) Install screws (4, fig.-14), lockwashers (3) and nuts (2) that secure pump (1) to the chassis.
NOTE
If you are installing the same pump you removed, use shims (5, 6 and 7, fig. 2-14) having the same thickness as
the ones removed. If a different pump is being installed, provide shims having proper thickness for as long the
bearing housing with the flywheel housing of the engine.
Step 2. Check for incorrect impeller-to-wear plate clearance.
a. Insert a feeler gage into the front opening of the volute and measure from the face of the impeller (20, fig. 2-15) to the face of the wear plate
(17).
b. The correct clearance should be 0.010 to 0.020 inch (0.(25 to 0.05 cm).
If the clearance between the face of the impeller and the face of the wear plate is not 0.010 to 0.020 inch (0.025 to 0.05 cm) the pump
must be disassembled and shims added to obtain the correct clearance.
Refer to malfunction one to remove, disassemble, reassemble and install the pump.
Step 3. Check for excessively worn wear plate.
a. Refer to malfunction one to remove and disassemble the pump.
b. inspect the wear plate for wear, scoring, and distortion.
If any damage to the wear plate is evident, replace it. Refer to Malfunction 1 and reassemble and install the pump.
Step 4. Check for defective shaft seal.
a. Use a hoist or other lifting device to support the weight of the pump (1, fig. 2-16). Remove nuts (2), lockwasher (3), and screws (4) that
secure the pump to the chassis frame.
2-20
TM 5-4320-234-34
Figure 2-16. Centrifugal pump removal and installation.
2-21
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CENTRIFUGAL PUMP CONTINUED
b.
Remove nuts and lockwashers that secure pump body to the bearing housing; slide the pump body straight out to disengage it from the
remainder of the pump which is secured to the engine.
c.
Disassemble the pump following the sequence of index numbers in figure 2-17.
2-22
TM 5-4320-234-34
Figure 2-17. Centrifugal pump disassembly and reassembly.
2-23
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CENTRIFUGAL PUMP CONTINUED
d.
Inspect shaft seal for cracks and excessive wear.
Replace a damaged shaft seal.
NOTE
The seal members are replaceable individually. When replacing the seal, be sure to replace all parts that are provided in the
seal kit.
(1)
Reassemble the pump by reversing the disassemble sequence In figure 2-17. Note the following:
(a)
Press the seal stationary member (28) into seal pla
te (29) before installing the plate. Lubricate the impeller shaft lightly with oil
and slide the seal rotating member (25) and spring into place on the shaft.
(b)
If the same impeller (20), and wear plate (17) are reassembled and no clearance change is indicated, use shims (22 and 23) of
the same thickness as those removed. If a new impeller and/or wear plate is installed, determine the shim thickness required
to obtain a clearance of 0.010 to 0.020 inch between the impeller and wear plate as follows.
(c)
Install impeller (20) on shaft without shims. Be sure that Impeller is seated firmly against the shaft shoulder.
(d)
Install volute (18, with wear plate (17) assembled, and secure with screws (12) and lockwasher (13).
(e)
Insert a feeler gage into the front opening of the volute and measure from the face of the impeller (20) to the face of the wear
plate (17).
(f)
Select shims (22 and 23) to equal the dimensions obtained less 0.010 to 0.020 inch (0.025 to 0.05 cm) clearance.
(2)
After reassembly, when using either new or used parts, recheck the clearance; it must be 0.010 to 0.020 inch (0.025 to 0.05 cm).
Check the impeller shaft for free rotation. It must turn freely, without catching or binding. If binding is evident, disassemble the
pump and correct the condition.
(3)
Use a hoist or other lifting device and install the pump on the chassis. Install nuts and lockwashers that secure the pump body to
the bearing housing.
(4)
Install screws (4, fig. 2-16), lockwashers (3) andnuts (2) that secure pump (1) to the chassis.
NOTE
If you are installing the same pump you removed, use shims (5, 6, and 7, fig. 2-16) having the same thickness as the ones
removed. If a different pump is being installed, provide shims having proper thickness for sling the bearing housing with the
flywheel housing of the engine.
7.
PUMP MAKES EXCESSIVE NOISE
Step 1.
a.
Check for defective impeller shaft bearings.
Remove drain plug (1, fig.2-18) from the centrifugal pump.
2-24
TM 5-4320-234-34
Figure 2-18. Centrifugal pump removal and installation.
2-25
TM 5-4320-234-34
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CENTRIFUGAL PUMP CONTINUED
b.
Disconnect all suction and discharge piping from the pump. Disconnect the suction and pressure gage piping from the pump.
c.
Place a rope sling around the pump and support the weight of the pump with a hoist or cran
e.
d.
Remove the nuts (2) and lockwashers (3) that secure the bearing housing of the pump (7) to the flywheel housing of the engine.
e.
Remove nuts (4), lockwashers (5) and capscrews (6) that secure the pump to the chassis. Operate the hoist or crane so that pump fast barely
clear the chassis frame. Pull the pump straight out to disengage the pump half of the flexible coupling from the engine half of the coupling. Be
careful not to lose the cushions that are installed between the coupling halves. Remove the pump and shims (8, 9 and 10).
f.
Remove sleeves (1, fig. 2-19) to release the cushions (2) from the coupling halves (7 and 13). Remove setscrew (3) that secures the coupling
half (7) to the impeller shaft; remove the coupling and key.
g.
Remove lockwire (4) and retaining ring (5) that secure the collar (6) to the coupling half; remove the collar.
h.
Remove capscrews (8) and lockwashers (9) that secure the drive plate (12) to the engine flywheel; remove the assembled coupling half (13)
and drive plate.
i.
Remove the capscrews (10) and lockwashers (11) that secure the coupling half (13) to the drive plate (12): remove the coupling half.
j.
Remove nuts and lockwashers that secure pump body to the hearing housing. Separate the bearing housing and pump body.
Figure 2-19. Pump coupling.
k.
Disassemble the bearing housing in the sequence indicated in figure 2-20.
2-26
TM 5-4320-234-34
Figure 2-20. Bearing housing.
Table 2-1. Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CENTRIFUGAL PUMP CONTINUED
WARNING
Clean all parts in a well-ventilated area. Avoid inhalation of solvent fumes and prolonged exposure of skin to cleaning
solvent. Dry cleaning solvent, P-D-680 or P-S-661, used to clean parts is potentially dangerous to personnel and property.
Do not use near open flame or excessive heat. Flash point of solvent is 100 F. - 138 F. (38 C.- 59 C.).
l.
Clean ball and roller bearings by replacing them into a wire basket and then immersing them into a container of fresh cleaning solvent (Fed.
Spec. P-D-680). Agitate the bearings in the solvent to remove all traces of old lubricants. After the bearings are cleaned, allow them to air
dry.
m.
Inspect the bearings for signs of scoring, cracked races, signs of overheating, and binding operation.
2-27
TM 5-4320-234-34
Table 2-1. Troubleshooting -- Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CENTRIFUGAL PUMP CONTINUED
Replace all bearings that are damaged.
(1)
Press bearings (8 and 10, fig. 2-20) onto the Impeller shaft (11). Secure bearings to the shaft with retaining ring (7 and 9).
(2)
Press grease seal (12) into the bearing housing (13) and grease seal (5) Into the bearing cap (4) before installing the shaft
and bearings in the bearing housing.
(3)
Pack the bearings and bearing cap with MlL-G-10924 grease; pack the area between the bearings in the bearing housing
three-fourths full of the same grease.
(4)
Press the shaft and assembled bearings into the housing until the bearings are seated. Install the preformed packing (6) and
bearing cap (4). Secure the bearing cap with the capscrews (2) and lockwashers (3), tightening them evenly In increments
until all are secure.
(5)
Install coupling half (13, fig. 2-19) on the drive plate (11); secure with six capscrews (10) and lockwashers
(11).
(6)
Install drive plate (12) on the engine flywheel and secure with capscrews (8) and lockwashers (9).
(7)
Install collar to coupling half and secure with retaining ring (5) and lockwire (4).
(8)
Install coupling half (7) and collar (6) on the end of the impeller shaft so that the keyway engages the key on the shaft.
Secure with setscrew (3).
(9)
Install three cushions (2) on each coupling half; secure each with sleeve (1).
(10)
Place a sling around the pump and install pump onhe
t chassis. Install shims (8. 9, and 10) having die same thickness as
the ones removed. Slide the pump into engagement with the engine so that the coupling halves are properly alined.
(11)
Secure the bearing housing to the flywheel housing with nuts (2) and lockwashers (3). Secure the pump feet to the chassis
frame with capscrews (6), lockwashers (5) and nuts (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
you will find applicable to several assemblies or
components of the pumping assembly which would
otherwise have to be repeated in each section of the
manual assigned to those assemblies and components.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (fed. spec. P-D-680)
used to clean parts is potentially
dangerous to personnel and property. Do
not use near open flame or excessive heat.
Flash point of solvent is 100 to 138 F (38 to
59 C).
2-6. Cleanliness
a.
Take care to ensure that your work area is
clean before starting to disassemble the engine or pump
parts.
b.
Clean the exterior of the engine or pump
before starting disassembly to prevent dirt from entering
the bearings or the other critical contact surfaces. Clean
the exterior of engine components with a cloth
dampened with cleaning solvent (fed. spec. P-D-680).
c.
If you clean the parts with compressed air,
make sure the air is free from dirt and contaminants.
2-28
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
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (fed. spec. P-D-680)
used to clean parts is potentially
dangerous to personnel and property. Do
not use near open flame or excessive heat.
Flash point of solvent is 100 to 138 F (38 to
59 C).
a.
Clean ball and roller bearings by placing
them into a wire basket and then immersing them into a
container of fresh cleaning solvent (fed. spec. P-D680). Agitate the bearings in the solvent to remove all
traces of old lubricants.
b.
After the bearings are cleaned, allow them to
air dry.
c.
Dip the cleaned and dried 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 you
disassemble. 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.
TM 5-4320-234-34
Section IV. REMOVAL AND INSTALLATION OF MAJOR COMPONENTS
AND ASSEMBLIES
2-9. Centrifugal Pump
a.
(1) Remove the drain plug (1, fig.
from the centrifugal pump.
Removal.
2-29
2-21)
TM 5-4320-234-34
Figure 2-21. Centrifugal pump, removal and installation.
2-30
TM 5-4320-234-34
(2) If you are installing the same pump you
removed, use shims (8, 9, and 10, fig. 2-21) having the
same thickness as the ones removed. If a different
pump is being installed, provide shims having proper
thickness for aligning the bearing housing with the
flywheel housing of the engine. Slide the pump into
engagement with the engine so that the coupling halves
are properly alined.
(2) Disconnect all suction and discharge
piping from the pump.
(3) Disconnect the suction and pressure
gage piping from the pump (TM 5-4320-234-12, para 447).
(4) Place a rope sling around the pump
and support the weight of the pump with a hoist or
crane.
(3) Secure the bearing housing of the
pump to the flywheel housing of the engine with nuts (2)
and lock washers (3). Secure the pump feet to the
chassis frame with cap screws (6), nuts (4) and lock
washers (5), making sure the shims are in place.
(5) Remove the nuts (2) and lockwashers
(3) that secure the bearing housing of the pump (7) to
the flywheel housing of the engine.
(6) Remove the cap screws (6), nuts (4),
and lock washers (5) that secure the pump to the
chassis. Operate the hoist or crane so that the pump
feet barely clear the chassis frame. Pull the pump
straight out to disengage the pump half of the flexible
coupling from the engine half of the coupling. Be
careful not to lose the cushions that are installed
between the coupling halves. Remove the pump and
shims (8, 9, and 10).
(7)
Installation.
(1)
(5)
Install the drain plug (1, fig. 2-21).
2-10. Flexible Coupling
a.
Removal and Disassembly.
(1) Remove the assembled pump and
bearing housing from the engine and chassis frame as
directed in paragraph 2-9. The one half of the coupling
assembly will remain with the engine; the other half will
remain with the pump.
Remove the flexible coupling (para 2-
10).
b.
(4) Connect the suction and pressure gage
piping (TM 5-4320-234-12, para 4-47).
Install the flexible coupling (para 2-10).
(2) Remove the sleeves (1, fig. 2-22) to
release the cushions (2) from the coupling halves (7 and
13).
2-31
TM 5-4320-234-34
Figure 2-22. Pump coupling, exploded view
(3) Remove the setscrew (3) that secures
the coupling half (7) to the impeller shaft; remove the
coupling half and key.
(4) Remove the lock wire (4) and the
retaining ring (5) that secure the collar (6) to the
coupling half; remove the collar.
not use near open flame or excessive heat.
Flash point of solvent is 100 to 138 F (38 to
59 C).
b.
(5) Remove the cap screws (8) and lock
washers (9) that secure the drive plate (12) to the
engine flywheel; remove the assembled coupling half
(13) and drive plate.
(6) Remove the cap screws (10) and lock
washers (11) that secure the coupling half (13) to the
drive plate (12); remove the coupling half.
Cleaning and Inspection.
(1) Clean the six cushions by wiping them
with a clean, dry cloth.
(2) Wash all remaining parts with cleaning
solvent (Fed. spec P-D-680); dry thoroughly.
(3)
brittleness,
cushions.
Inspect the cushions for cracks, wear,
and deterioration; replace damaged
(4) Inspect the coupling halves for cracks,
worn teeth, worn bores, damaged threads, and other
damage; replace damaged coupling halves.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash ex posed skin thoroughly.
Dry cleaning solvent (fed. spec. P-D-680)
used to clean parts is potentially
dangerous to personnel and property. Do
(5) Inspect the drive plate for cracks,
distortion, and worn mounting holes; replace a damaged
drive plate.
(6) Inspect all other parts for cracks,
distortion and other damage; replace damaged parts.
2-32
TM 5-4320-234-34
c.
(2) Disconnect the fuel lines connecting
the fuel pump to the fuel tank (TM 5-4320-234-12, para
4-21).
Reassembly and Installation.
(1) Position the coupling half (13, fig. 222) on the drive plate (12); secure with six cap screws
(10) and lock washers (11).
CAUTION
(2) Position the assembled drive plate and
coupling half on the engine flywheel; secure with eight
cap screws (8) and lock washers (9).
(3) Position the collar (6) on the coupling
half (7); secure with the retaining ring (5). Make sure
the retaining ring is fully seated in the ring groove and
install the lock wire (4) into the retaining ring.
(4) Position the assembled coupling half
(7) and collar (6) on the end of the impeller shaft so that
the keyway engages the key on the shaft. Secure with
the setscrew (3).
(5) Install three cushions (2) on each
coupling half; secure each with a sleeve (1).
(6) Install the assembled pump and
bearing housing onto the engine and chassis frame
(para 2-9).
(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.
2-11. Engine
a.
Removal. Remove the engine from the
centrifugal pump and chassis frame as follows:
(1)
Although this engine is equipped with a
reverse polarity protector to prevent
alternator damage due to reverse-polarity
connections, you should always take
special precautions when connecting and
disconnecting electrical leads and cables.
Do not ground the field terminal between
the alternator and regulator.
Do not
operate the alternator in an open circuit
with the rotor winding energized. Do not
ground the alternator output circuit. You
should take care to prevent reversing
polarity of the electrical system. When you
use a battery booster or fast charge, make
sure the leads are connected with the
correct polarity. Failure to follow these
instructions may damage the rectifiers,
voltage regulator, and wiring.
(4) Remove the bolts (3 and 4, fig. 2-23),
flat washers (5), nuts (1), and lock washers (2) that
secure the engine to the chassis frame. Use a suitable
lift truck to raise the engine from the chassis, taking care
to insert the forks under structural members only.
Remove the centrifugal pump (para 2-
9).
2-33
TM 5-4320-234-34
Figure 2-23. Engine, removal and installation
b.
Installation
(2) Connect the battery cables to the
battery and to the engine. Reread the caution in
subparagraph a above to prevent damage to the
components of the electrical system before you connect
the battery cables.
(1) Use a lift truck to position the engine
on the chassis frame. Take care to insert the forks
under ; structural members only. Secure the engine to
the frame with bolts (3 and 4, fig. 2-23), nuts (1, block
washers (2), and flat washers (5).
(3) Install the fuel lines connecting the
engine to the fuel tank (TM 5-4320-234-12, para 4-21).
(4)
2-34
Install the centrifugal pump (para 2-9b).
TM 5-4320-234-34
CHAPTER 3
REPAIR OF ENGINE COMPONENTS
Section I. GENERAL
3-1. Introduction
3-2. Scope
This chapter provides you with repair and overhaul
instructions for various engine components. It includes
information regarding disassembly, inspection of parts,
repair, and overhaul.
Only those components which are solely within the
scope of direct and general support maintenance are
covered. For repair of components which are within the
scope of operator/crew and organizational maintenance,
refer to TM 5-4320-234-12.
Section II. REPAIR OF GOVERNOR
3-3. Description
Engine speed is controlled by the inter-operation
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 throws 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 on the
3-1
carburetor and as the engine speed tends to increase,
the throttle is closed slightly, decreasing the 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, increasing the engine speed. In
this manner, a balanced condition is reached, and the
engine speed remains constant at the level determined
by the throttle control setting.
Adjustment of the
governor is made by changing the tension of the spring
which applies tens ion to the external governing lever
and tends to keep the dished race against the flyballs.
Tightening the spring raises engine speed at any
particular throttle control setting. Decreasing spring
tension lowers the speed.
TM 5-4320-234-34
Figure 3-1. Operation of engine speed regulating system.
b.
Remove the magneto (TM 5-4320-234-12,
para 4-35).
3-4. Removal
a.
Disconnect the ball joint on governor-tocarburetor control rod from the lever on the governor.
c.
Remove the governor and related parts as
shown in figure 3-2.
3-2
TM 5-4320-234-34
Figure 3-2. Governor removal, exploded view
c.
Inspect the governor for cracks, missing
parts, wear and other obvious damage. Check the
rotation of the governor drive shaft. It must turn freely
without catching or binding. Check the movement of the
governor lever shaft in its needle bearings. It must pivot
freely without catching or binding and without excessive
play. Replace a damage governor.
3-5. Cleaning and Inspection
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (fed. spec. P-D-680)
used to clean parts is potentially
dangerous to personnel and property. Do
not use near open flame or excessive heat.
Flash point of solvent is 100 to 138 F (38 to
59 C).
3-6. Installation
a.
Install the governor by reversing the removal
procedure. Refer to figure 3-2 and note the following:
(1) The magneto must be removed to
enable proper timing of the governor drive gear with the
timing gear.
a.
Clean the exterior of the governor with a
cloth dampened with cleaning solvent (fed. spec. P-D680). Wipe dry.
(2) Sight through the magneto mounting
hole to check that the two marked teeth of the governor
drive gear engage the single marked tooth of the cam
gear as shown in figure 3-3.
Ignition timing is
dependent upon this relationship because the magneto
is driven by the governor drive gear.
b.
Clean all remaining parts with cleaning
solvent; dry thoroughly.
3-3
TM 5-4320-234-34
b.
Install the magneto (TM 5-4320-234-14, para 4-
c.
Adjust the governor (TM 5-4320-234-12, para 4-
35).
27).
Figure 3-3. Timing marks on governor drive gear and
cam gear.
Section III. REPAIR OF RADIATOR
CAUTION
Do not exceed 10 psi air pressure for
radiator testing.
Excess pressure will
damage the radiator. Make sure that you
completely drain the radiator core 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 leaks could remain
undetected.
b.
Make sure the radiator is completely drained
of coolant. Plug all openings, except one through which
compressed air can be applied. Immerse 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 leaks. If leaks are found, mark the areas for
repairs.
c.
Inspect all hardware for cracks and for worn
or stripped threads.
d.
Replace all parts damaged beyond repair.
3-11. Repair
3-7. Description
Liquid coolant is pumped through passages in the
engine to remove the heat of combustion. As the hot
coolant is pumped from the engine, it enters the
radiator, which is a large heat exchanger consisting of
tubes and fins that 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.
The coolant from the radiator is recirculated through the
engine to complete the cycle.
3-8. Removal
Remove the radiator (TM 5-4320-234-12, para 432).
3-9. Cleaning
a.
You may clean the exterior of the radiator by
flushing in a reverse-flow direction with a stream of
water to remove all bugs and debris. Remove any
greasy or oil deposits with cleaning solvent (Fed. Spec.
P-D-680).
b.
Reverse-flush the interior of the radiator,
using a flushing gun.
a.
Repair leaks by soldering. Be sure that you
do not block or retard circulation through any tubes.
There shall be no blocked tubes upon completion of
repairs.
3-12. Installation
c.
If flushing fails to remove scale from the
interior of the radiator, boil it out in accordance with
current directives.
3-10. Inspection and Testing
a.
Inspect all parts for cracks, leaking tubes or
gaskets, damaged threads, or other obvious damage.
Install the radiator (TM 5-4320-234-12, para 4-32).
Section IV. REPAIR OF OIL SYSTEM COMPONENTS
3-13. 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
repair and overhaul.
b.
An oil filter with its related piping is mounted
3-4
TM 5-4320-234-34
on the exterior of the engine to remove from the engine
oil any impurities and particles that could cause engine
wear. This filter has a replaceable cartridge.
3-14. Engine Oil Filter
c.
The engine oil pressure is regulated by a
relief valve mounted in the engine cylinder block. The
valve consists mainly of a spring-loaded, spool-type
valve which is seated in a bore in the block. The greater
the spring pressure is which loads the valve, the greater
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. Oil pressure adjustment is
described in paragraph 3-15.
(1) Drain the oil from the engine (TM 54320-234-12, para 3-3).
a.
Removal.
(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 3-4.
3-5
TM 5-4320-234-34
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Oil pressure sender
Tube
Elbow
Tee
Elbow
Nipple
Connector
Tee
Bushing
Nipple
11.
12.
13.
14.
15.
16.
17.
18.
19.
Hose
Elbow
Nut
Lock washer
Flat washer
Oil filter assembly
Nut
Lock washer
Oil filter bracket
Figure 3-4. Engine oil filter mounting, exploded view.
3-6
TM 5-4320-234-34
b.
Disassembly. Disassemble the oil filter as shown in figure 3-5.
1.
2.
3.
4.
5.
6.
7.
cove screw
Screw gasket
Decal
Cover
Cover gasket
Spring
Filter element
8.
9.
10.
11.
12.
13.
14.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (fed. Spec. P-D-680)
used to clean parts is potentially
dangerous to personnel and property. Do
not use near open flame or excessive heat.
Flash point of solvent is 100 to 138 F (38 to
59 C).
(2) Clean all remaining parts with cleaning
solvent (Fed. Spec. P-D-680). Use compressed air to
blow debris from tubes and hoses.
(3) Inspect the hose for abrasion, cracks,
deterioration, damaged threaded ends, and collapsed
walls; replace a damaged hose.
(4) Inspect the tube for dents, cracks,
damaged tube nuts, and collapsed walls; replace a
damaged tube.
(5) Inspect the filter body and cover for
cracks, distortion, dents, damaged threads, and other
damage; replace a defective body or cover.
(6) Inspect the oil pressure sender for
cracks, dents, and damaged threads. Check the sender
in series with a 12-volt battery and the oil pressure gage
mounted on the control panel. Use a low pressure,
calibrated air supply when you run the test. The sender
must provide proper resistance at various pressures to
register the required readings on the associated gage.
Replace damage or inaccurate parts.
(7) Inspect all other parts for cracks,
distortion and damaged threads. Replace damaged
parts.
d.
Reassembly and Installation. Reassembly
and installation are the reverse of removal and
disassembly. Refer to figure 3-4 and 3-5. After filling
the engine lubricating system with oil per LO 5-4320234-12, start the engine and check for oil leaks. Correct
any leaks.
3-15. Engine Oil Pressure Adjustment
If oil pressure is consistently low, you can make
the necessary pressure adjustment as follows:
a.
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.
b.
If the engine oil pressure is not within the
required range, shut off the engine and remove the plug
(1, fig. 3-6) and gasket (2) from the carburetor side of
the engine block. Remove the valve spring (3) and
pressure adjusting washer (4).
Decal
Oil filter body
Screw
Lock washer
Nut
Decal
Oil filter clamp
Figure 3-5. Oil filter assembly, exploded view
c.
Cleaning and Inspection.
(1) Discard and replace the oil filter
element and gaskets.
3-7
TM 5-4320-234-34
c.
To increase oil pressure, add a washer between
the spring and oil pressure regulator valve. More than four
washers should not be used. If four washers do not fulfill
the required range, either the spring is faulty or other
engine troubles exist.
d.
After you make the adjustments, check that the
oil pressure remains in the required ranges during
operation.
Figure 3-6. Oil pressure adjustment.
Section V. REPAIR OF ELECTRICAL SYSTEM COMPONENTS
engine operating speeds could severely damage the
starting motor. Reengagement of the starter while the
engine is running is prohibited by the starter disengage
relay.
3-16. Description of Engine Electrical System
a.
The alternator and regulator are typical
automotive types in which the alternator output is
controlled through the voltage regulator, depending
upon the state of charge of the battery. When the
battery charge is low, the voltage regulator increases the
strength of the alternator field to increase the output of
the alternator. When the battery charge is
normal, the output of the alternator decreases to near
zero.
3-17. Alternator
CAUTION
Disconnect the battery cable from the
positive
battery
terminal
before
disconnecting any other leads from the
engine components. This precaution will
prevent shorts which could damage the
alternator, voltage regulator, or other parts.
b.
Reversed polarity connections in the
charging system can severely damage the alternator.
To prevent this damage, the system is protected by a
reverse polarity protector mounted on the voltage
regulator bracket.
a.
Removal. Remove the alternator as directed
in TM 5-4320-234-12, para 4-38.
c.
The engine starter is a solenoid-operated
type in which the solenoid switch is mounted on the top
of the starter. The solenoid switch uses electrical
energy to pull the starter drive into engagement with the
flywheel ring gear and to form the electrical circuit which
energizes the starter after the drive is engaged. When
the engine starts, the starter drive is disengaged,
preventing the engine from driving the starter since
b.
Alternator Brush Replacement.
(1) Remove the two assembled washer
screws (4, fig. 3-7) that secure the brush cover (5) to
the alternator; carefully pull the cover away from the
alternator.
3-8
TM 5-4320-234-34
Figure 3-7. Alternator assembly, exploded view.
3-9
TM 5-4320-234-34
(2) Remove the isolation diode assembly
(26). When removing the diode assemblies, note the
positions of the insulating sleeves and washers to
ensure reassembly in proper positions.
(2) Remove the two terminal screws (7),
nuts (8), insulating washers (9), leads (12), washers
(11), and bushings (10) from the brush cover.
(3) Remove the two screws (13) that
secure the insulator (14) and brush assembly (15) to the
alternator; remove the brush assembly with the attached
electrical leads (12).
(3) Remove the square nuts (28) and
through bolts (20) that secure the front housing (32) to
the rear housing (41).
(4) Using a small bladed screwdriver, pry
at several points around the stator to remove the
assembled rotor and front housing. Do not insert the
screwdriver blade more than 1/16 inch, or damage to
the stator windings may occur while you are separating
the front housing from the stator.
(4) Inspect the brush assembly for cracks,
signs of over-heating, and distortion. Check that the
brushes slide freely in the brushholders and that the
brush springs provide sufficient brush tension. Inspect
the brushes for cracks, oil saturation, and wear. If you
find that the brushes are worn to less than 3/16 inch
(0.468 cm), oil soaked, or cracked, replace the brush
assembly.
(5) Clamp the front housing lightly in a vise
and, using long nose pliers, reach through the front
housing (32) to compress the ears of the bearing
retainer (30) and lift it free of its recessed seat.
(5) If the brush assembly passes your
visual inspection, check the electrical condition of the
assembly. Refer to figure 3-8. Check that continuity
exists between points A and B and between points C
and D, but that no continuity exists between point E and
points A or C.
(6) With the bearing retainer free of the
recess, you can remove the assembled rotor and
bearings by tapping the end of the rotor shaft on a block
of wood while holding the housing.
(7) Place the assembled stator (33) and
rear housing (41) on a clean, smooth working surface
that is free of metal chips. Remove the lock nuts (34)
and insulating washers (35) that secure the studs of the
diode assemblies (36 and 37) to the rear housing (41).
Carefully push the studs out of the housing and separate
the assembled diode assemblies and stator (33) from
the rear housing.
(8) Do not disassemble the rotor unless the
bearings or slip rings are damaged and must be
replaced. If you must remove the bearings and slip
rings, proceed as follows:
Figure 3-8. Alternator brush assembly, showing
continuity paths.
(6) Use a new brush assembly if the
inspection indicates faults.
(a) Use a bearing puller to remove
the front bearing from the rotor shaft.
(7) Position the brush assembly (15, fig.
3-7) and insulator (14) on the alternator; secure with two
machine screws (13).
(b) Remove any sealant retaining the
rotor winding leads to the slip ring.
(c) Unsolder the rotor leads from the
slip ring terminals. Unwind the leads from the terminals,
taking care you do not bend or stress leads excessively.
(8) Connect the electrical leads (12) from
the brush assembly to the brush cover (5) with the
terminal screws (7), nuts (8), insulating washers (9), and
washers (11). Make sure you have the bushings (10) in
place.
(d) Remove the screw (42) from end
of shaft. Thread a 1/4-28 x 1-1/4-inch long screw into
the slip ring hub; this process will back the slip ring
assembly (44) off the shaft.
(9) Position the brush cover (5) on the
alternator; secure with two assembled washer screws
(4).
(e) Use a bearing puller to remove
the rear bearing (45), taking care you do not damage the
rotor leads.
c.
Disassembly. Disassemble the alternator
following the sequence indicated in figure 3-7. Note the
following:
d.
Cleaning and Inspection.
(1)
(1) To remove the pulley (18), wrap the
alternator drive belt around the pulley and clamp it in a
vise so that the belt protects pulley edges. Strike the
end of the rotor shaft with a soft mallet or plastic
hammer to jar loose the pulley.
Discard and replace gaskets.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent
3-10
TM 5-4320-234-34
(11) Inspect the slip rings for cracks, wear
grooves, damaged or loose lead connections, or other
damage. You can restore a smooth surface to the slip
rings with fine crocus cloth. Wipe all residue from slip
rings. Replace the slip rings if they are too worn to be
reused.
fumes and prolonged exposure of skin to
cleaning-solvent.
Wash exposed skin
thoroughly.
Dry cleaning solvent (fed.
spec. P-D-680) used to clean parts is
potentially dangerous to personnel and
property. Do not use near open flame or
excessive heat. Flash point of solvent is
100 to 138 F (38 to 59 C).
(12) Inspect the rotor bearings for wear,
catching or binding operation, or missing or damaged
seals. Replace the bearings if defective. While the
bearings are off the rotor shaft, you should inspect the
shaft bearing surfaces for wear.
(2) Use a cloth dampened with cleaning
solvent (fed. spec. P-D-680) to clean the diode
assemblies, stator, and rotor. Wipe dry.
(13) Inspect the rotor shaft and body for
stripped threads, worn key slot, cracked or marred pole
fingers and shaft. Replace a damaged rotor.
(3) Wipe the bearings with a cloth, taking
care that you do not disturb the bearing seals.
(4) Clean all remaining parts with cleaning
solvent; dry thoroughly.
(14) Inspect all other parts for cracks,
distortion, or damaged threads. Replace all damaged
parts.
(5) Inspect and test the brush assembly as
directed in sub-paragraph b above.
e.
(6) Inspect the pulley for cracks, groove
wear, and damage to the keyway. Replace a damaged
pulley.
Testing.
NOTE
Use only rosin core solder to solder diodes
to the stator leads. If you use acid core
solder, the connection will corrode,
resulting in an open circuit and damage to
the components.
(7) Check the fan for bent or missing fins
and mounting hole wear. Replace if damaged.
(8) Inspect all insulating sleeves and
washers for cracks, separations and other damage.
Replace as necessary.
(1) Test the diodes with a diode tester
according to the instructions of the equipment
manufacturer. To test, it will be necessary for you to
unsolder the leads from the stems of the positive and
negative diode assemblies for individual testing. When
you solder and unsolder leads from the diodes, use long
nose pliers to grasp the diode stem between the diode
and the stator lead to be removed. This will give better
heat dissipation and protect the diode from damage.
You should make note of the diode to stator lead
connections to facilitate reassembly. If one diode is
bad, you must replace the entire diode assembly. The
positive diode assembly has red printing on the diode
body; the negative diode assembly has black printing.
Refer to figure 3-9.
(9) Inspect the front and rear housings for
cracks, bearing bore wear, distortion, damaged threads,
and other obvious damage. You should remove any
burrs with a fine stone or file. Replace either housing if
not reparable.
(10) Inspect the stator for gouged or
discolored windings.
Discoloration of the winding
insulation is an indication of an overheated stator that
may result in shorted or grounded windings.
3-11
TM 5-4320-234-34
Figure 3-9. Stator winding and connections.
10. Unsolder and separate the common leads; pull back
the insulating sleeves exposing the opposite end leads.
Connect the ohmmeter or test lamp probes to each pair
of the following test points:
(2) With the stator disconnected from the
diode assemblies, test it for leakage and continuity. You
can use either a good quality ohmmeter or test lamp (12
volts or 120 volts) to test the stator. Refer to figure 3-
Point A to point B
Point A to point C
Point B to point C
Point A to point D
Point B to point D
Point C to point D
3-12
TM 5-4320-234-34
(1) Make certain that all positive and
negative rectifier diodes are soldered to the proper
stator leads and that the stator common leads have
been resoldered together after testing.
(2) Press the bearing (31) into the front
housing (32), using a driver tool that exerts pressure on
the outer bearing race only. Place the bearing retainer
(30) in recess, making certain the retainer ears line up
with openings in the housing. Use a wooden dowel to
exert pressure on the retainer when you seat its edge in
the recess.
(3) With the rotor leads in position on the
rotor assembly (46), carefully press the rear bearing (45)
onto the rotor shaft, exerting pressure on the inner race
only.
(4) Guide the rotor winding leads through
the square passage in the slip ring hub. Hand press the
slip rings (44) onto the shaft while you maintain
alinement of rotor leads and passage. Install screw (42)
and washer (43) and tighten to 45 inch-pounds. Before
soldering the rotor winding leads to the slip rings, make
certain that fiber insulating washers are in place on the
inner slip ring terminals.
Wrap leads around the
terminals and solder with rosin core solder. Secure
wires to the end of the rotor and slip rings with a
synthetic rubber sealer. Retest the rotor circuits to
ensure that a short or ground did not develop during
repair. Refer to subparagraph e(5) above.
Figure 3-10. Stator test points.
(3) The resistance should be infinite or test
lamp should not light in all of the above tests. If the
resistance reading is not infinite or in the test lamp lights
in any test, high leakage or a short exists between stator
windings, or between a stator winding and the
lamination. Replace the stator.
(4) Test for stator continuity by connecting
the ohmmeter or test lamp probes to each pair of the
following test points:
(5) With the rotor properly supported on an
arbor press, use a driver sleeve on the inner bearing
race and press the front housing (32) onto the rotor.
Point A to point A
Point B to point B
Point C to point C
(6) Position the spacer (21), fan (19), and
pulley (18) in place on the rotor shaft. Secure with the
lock washer (17) and nut (16). Tighten to 35 footpounds torque.
You should have a reading of approximately 0.1 ohm or
the test lamp should light in each test.
Infinite
resistance or an unlighted test lamp indicates an open
winding. Replace the stator if it fails any of the above
tests or, if the alternator has been disassembled
because of an electrical malfunction, replace the stator
after all other components have been checked and
found to be satisfactory.
(7) Position the insulating washers (39)
and sleeves (38) on the studs of the diode assemblies
(36 and 37). Position the diode assemblies in the rear
housing so that the washers and sleeves electrically
insolate the diode assemblies. Secure with insulating
washers (35) and nuts (34).
(5) Use a multimeter to test the rotor and
slip ring assembly. Connect the slip rings in series with
a multimeter and a 20-volt supply. There should be a
1.20- to 2.5-amp current draw. Your multimeter should
indicate 11 to 14 ohms resistance across the slip rings.
Connect one of the multimeter or test lamp probes to
the rotor body and the other on either slip ring. You
should have an infinite resistance reading or the test
lamp should not light. If this does not occur, then either
the slip rings, ring connecting leads, or rotor winding is
grounded. Replace a faulty rotor.
(8) With rear bearing retainer (40) in place,
position the rear housing (41) over the slip ring end of
the rotor and hand press the housings together. Aline
the slots in the stator with the openings in the housings
and install the through bolts (29). Install nuts (28) and
tighten to 50 to 60-inch pounds (6.9150 to 8.2980 kgm)
torque. Turn the rotor by hand to check for binding of
bearings. Rotor must rotate freely.
(9) Install the isolation diode (26), noting
the proper position of the plate insulators (25, 27, and
35).
f.
Reassembly. Reassembly is essentially the
reverse of disassembly. Refer to figure 3-7. Pay
particular attention to the following:
3-13
TM 5-4320-234-34
(1) Mount the alternator in a test fixture
capable of providing 3000 rpm.
Secure the diode with nuts (24).
g.
Bench Test.
The following test will
determine the current producing capability of the
repaired alternator.
(2) Connect fixture circuit leads and
instruments to the alternator terminals as shown in
figure 3-11.
Figure 3-11. Alternator bench test circuit.
(3) With the carbon pile turned off to avoid
discharging the battery, set the field rheostat in
maximum resistance position.
If you have determined by testing (TM 5-4320234-12, para 4-39) that the voltage regulator should be
adjusted to suit your operating conditions, proceed
according to either of the following methods.
(4) Start the test fixture, and operate at
1500 rpm for a few minutes to normalize operating
temperature.
a.
You can change the voltage approximately
0.6 volt higher or lower by using a metal strap provided
on the underside of the regulator case. Raise the
voltage 0.6 volt by placing the metal strap across the
terminals marked HI. Secure strap with the terminal
nuts. Lower the voltage 0.6 volt by placing the metal
strap across the terminals marked LO.
(5) Increase the alternator speed to 3000
rpm and, at the same time, apply the carbon pile load to
the battery to keep the charging voltage below 28.0
volts. At 3000 rpm, the alternator should provide a
minimum current output of 28 amperes.
b.
If the step adjustment described above did
not give the exact system voltage you desire, follow this
procedure:
(6) The charging voltage can be adjusted
by the voltage regulator when the alternator is installed
on the engine.
(1) With the engine off, connect a
voltmeter to the battery and connect an ammeter in
series with output of the alternator as shown in figure 312.
h.
Installation. Install the alternator following
procedures given in TM 5-4320-234-12, para 4-38.
3-18. Voltage Regulator Adjustment
3-14
TM 5-4320-234-34
Figure 3-12. Voltage regulator adjustment circuit.
cover and screws. Reconnect the field, and operate for
no more than 5 minutes to ensure that you have
obtained the desired change in voltage.
(2) Operate the engine at fast idle (700 to
1000 rpm) to stabilize the electrical system until the
voltmeter stops showing a charge. This should occur
between 5 to 15 minutes.
3-19. Starting Motor
(3) Leave the engine running and remove
bakelite covered field connector on back of alternator.
Remove the four cover screws and remove cover from
voltage regulator. Reconnect the field to the alternator.
CAUTION
Disconnect the battery cable from the
positive
battery
terminal
before
disconnecting any other electrical leads
from the engine components. This will
prevent shorts which could damage the
alternator, voltage regulator, and other
parts.
CAUTION
The variable voltage control is connected
to alternator output and is electrically hot.
Do not let adjustment tool touch anything
but voltage control.
a.
Removal. Remove the starting motor (TM 54320-12, para 4-42).
(4) Use a No. 2 Phillips screwdriver to
adjust the voltage control. Turn the control a few
degrees counterclockwise if you want to reduce voltage,
or turn it clockwise to increase voltage. Stops are
provided in the control to limit rotation to less than 1/2
turn total. Do not try to force control beyond stops.
b.
Pinion Clearance Check. After removing the
starting motor, check pinion clearance. The clearance
cannot be adjusted, but improper clearance will indicate
worn parts and the need for starting motor replacement.
To check the pinion clearance, refer to figure 3-13 and
proceed as follows:
(5) After
adjustment,
remove
field
connector on back of alternator. Reinstall the regulator
3-15
TM 5-4320-234-34
pinion stop (fig. 3-14). The clearance shall be 0.010 to
0.140 inch (0.0250 to 0.3500 cm).
Figure 3-13. Circuit for checking pinion clearance.
(1) Disconnect the motor field coil
connector from the solenoid motor terminal and insulate
it carefully.
(2) Connect a 24-volt battery from the
solenoid switch terminal to the solenoid frame.
Figure 3-14. Checking pinion clearance.
(3) With one end of jumper connected to
the solenoid motor terminal, momentarily strike the
other end against the starter frame. This will shift the
drive assembly pinion into the cranking position where it
will remain until the battery is disconnected.
c.
Starter Brush Replacement.
(1) Remove the through bolts (3, fig. 3-15)
that secure the commutator end frame (4) to the starting
motor. Pull straight out on the end frame to disengage
the end frame bushing from the rotor shaft.
(4) Push the pinion back toward the
commutator end to eliminate slack movement. Using a
feeler gage, measure the distance between pinion and
3-16
TM 5-4320-234-34
Figure 3-15. Starting motor, exploded view.
3-17
TM 5-4320-234-34
(2) Remove the support pins (6) to release
the grounded brush holders (10), insulated brush holders
(11), and brush springs (7) from the brush supports.
Remove the brush screws (8) that secure the brushes
(9) to the brush holders; you can now remove the
brushes.
(3) Remove the screws (14), nuts (12), and
washers (13) that secure the brush leads (15) to the
brush support; remove the brush leads.
(4) Replace the brushes if you find them
chipped, oil soaked, or worn to less than 5/16 inch
(0.7812 cm). Replace any other parts that are cracked,
worn, or distorted.
(5) Install the brushes and related parts as
shown in figure 3-15. Before installing the commutator
end frame (4), seat the brushes on the commutator
using 00 sandpaper.
NOTE
Thecommutator on the armature shaft must be smooth and concentric,
free from burrs, scoring, high segments, burned segments, or other
damage. You should replace the starting motor if the commutator is
damaged.
(6) Install the commutator end frame (4) with
the through bolts (3).
d. Testing. To perform a no-load test,
connect the starting motor in series with a fully charged
24-volt battery, an ammeter of 0to 500-ampere range
and a large variable carbon pile resistor as shown in
figure 3-16. Also connect a voltmeter into the circuit.
You will also need a tachometer to measure armature
speed. Energize the starting motor and adjust the
variable resistor until you have a reading of 20 volts.
Armature rotation should be within the range of 3300 to
5600 rpm with a current draw between 40 and 75
amperes. Interpret the results as follows:
Figure 3-16. Starting motor no-load test setup.
(1) Current draw and no-load armature speed
within the above limits indicate normal condition of the
starting motor.
(2) Low free speed or high current draw
indicates too much friction, caused by damaged
bearings or a bent shaft, a shorted armature, or a
grounded armature or field.
(3) No rotation with high current draw
indicates a grounded field terminal or frozen bearings.
(4) Failure to operate with no current draw in
dicates an open field circuit, open armature coils (this
condition is normally accompanied by badly burned
commutator bars), or lack of continuity between brushes
and commutator.
(5) Low free speed with low current draw
indicates high internal resistance due to poor
connections, defective leads, or a dirty commutator.
(6) High free speed with high current draw
indicates a shorted field.
e.
Disassembly. Disassemble the start
motor
3-18
TM 5-4320-234-34
(7) Use a growler to test the armature for
shorted windings. Shorts can sometimes be corrected
by removing metal particles imbedded between
commutator bars. Replace armature if short cannot be
located and corrected.
(8) Use a 110-volt test lamp and check for
continuity between adjacent commutator bars.
If
continuity does not exist, then the armature windings are
open.
Check for loose connections between the
conductors and the commutator. Poor connections will
cause arcing and burning of the commutator.
(9) Use the test lamp to check for continuity
between commutator bars and armature shaft.
If
continuity exists between commutator bars and
armature shaft, the armature windings are grounded.
Replace a grounded armature.
(10) Inspect the field coil windings in the frame
for damaged insulation, broken wires, and damaged
terminals. Revarnish damaged insulation. Replace
frame and field assembly if badly damaged.
(11) Disconnect the field coil ground
connections and, using the test lamp, check for grounds
between each winding lead and frame. Check for open
windings by connecting test lamp probes to the winding
leads. Continuity must exist. Replace field windings
that are open or grounded.
(12) Inspect the pinion housing sleeve bearing
for scoring and wear. Press a damaged bearing from
the housing, and press a new bearing into the housing.
g. Reassembly. Reassembly is essentially the reverse
procedure of disassembly refer to figure 3-15. Pay
particular attention to the following:
(1) After you install the drive assembly (35)
and bearing (34) onto the armature shaft, place the
retainer (33) onto the shaft with the cupped surface
facing the snap ring groove. Place the snap ring (32)
onto the shaft. Force the snap ring over the shaft end
by placing a block of wood on it and lightly tapping with
a hammer. Slide the ring into the groove. To force the
retainer over the snap ring, place a suitable washer over
the shaft, and squeeze retainer and washer together
with pliers. Remove the washer and install the collar
(31).
(2) After you install the solenoid, apply a
sealing compound between the field frame, flange and
solenoid junction.
h. Installation. Install the starting motor (TM 5-4320234-12, para 4-42).
3-20. Radio Interference Suppression
a. Description. Essentially, suppression is attained by
providing a low resistance path to ground for stray
currents. The methods used include shielding the
ignition and high frequency wires and grounding the
frame with bonding straps.
following the sequence indicated in figure 3-15. Note
the following.
(1) If you have already removed the brushes,
be sure to remove screw (1) and lock washer (2) to
disconnect the field coil connections from the solenoid
motor terminal.
(2) Before removing the pinion drive
assembly (35), you must remove the retainer (33). To
do this, slide a metal cylinder on the shaft that will make
contact with the retainer edge only. Drive the retainer
toward the armature core and off the snap ring (32).
Remove the snap ring from the groove in the armature
shaft and continue disassembly.
(3) Do not remove the sleeve bearing (30)
from the pinion housing (29) unless inspection indicates
bearing is damaged.
(4) Do not disassemble the field coils (45 and
47) from frame unless tests indicate they are damaged
and must be replaced.
f. Cleaning and Inspection.
(1) Discard and replace gasket and oil seal.
WARNING
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
skin to cleaning solvent. Wash
exposed skin thoroughly.
Dry
cleaning solvent (fed. spec. P-D680) used to clean parts is
potentially
dangerous
to
personnel and property. Do not
use near open flame or excessive
heat. Flash point of solvent is 100
to 138 F (38 to 59 C).
CAUTION
Saturating electrical parts with
cleaning solvent will damage
them.
(2) Clean the solenoid switch, armature, field
frame and coil assembly, and drive assembly with a
cloth dampened lightly in cleaning solvent (fed. spec.
P-D-680). Blow dry with clean, dry compressed air.
(3) Clean all other metal parts thoroughly in
cleaning solvent. Dry thoroughly with compressed air.
(4) If necessary, you may clean the armature
commutator with No. 00 sandpaper. Do not use emery
cloth.
(5) Inspect the brushes as directed in
subparagraph c above.
(6) Inspect the armature for damaged
insulation, worn or out-of-round commutator, and
damaged bearing surfaces on shaft.
Revarnish
damaged insulation, allowing the varnish to soak into
the windings.
You can smooth damaged bearing
surfaces with crocus cloth.
Replace armature if
damaged beyond repair.
b. Replacement of Suppression Components. This
equipment uses no primary radio suppression com3-19
TM 5-4320-234-34
ponents.
You can replace the secondary radio
suppression components as follows: (1) Replace the
shielded spark plug cables as
directed in TM 5-4320-234-14, para 4-35. (2) Replace
the magneto ground strap as directed in TM 5-4320-23412, para 4-35.
Section VI. REPAIR OF ENGINE MOUNTING
3-21. Description
(1) Remove the engine from the centrifugal
pump assembly (para 2-9).
(2) Remove the engine housing from the
engine (TM 5-4320-234-12, para 4-19).
(3) Remove the radiator (TM 5-4320-234-12,
para 4-32).
(4) Support the engine with a hoist engaged
in the lifting eye at the top of the engine.
(5) Remove the tie rod and related parts
(items 1 through 9, fig. 3-17) that connect the radiator
support (25) with the flywheel housing.
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 engine vibration, preventing it from being
transmitted to the associated equipment. The radiator
support is connected to the flywheel housing by an
adjustable tie rod.
3-22. Engine Support
a. Removal.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Nut
Lockwasher
Nut
Lockwasher
Nut
Nut
Nut
Nut
Support tie rod
Cotter pin
Nut
Flatwasher
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
Lockwsher
Nut
Lockwasher
Capscrew
Lockwasher
Ground strap
Gear cover stud
Flatwasher
Support mount
Mount retainer
Grommet
Radiator support
Figure 3-17. Engine mounting parts, exploded view.
3-20
TM 5-4320-234-34
CAUTION
Do not rest the engine on its oil
pan. This may damage the oil
pan.
(2) Inspect the rubber mounting parts for
cracks, deterioration, cuts, loss of resiliency, and other
damage; replace damaged mounting parts.
(3) Inspect the support tie rod for damaged
threads and distortion; replace damaged rod.
(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, sandpaper
the end terminals to ensure a good electrical contact
between the radiator support and engine at installation.
(6) Remove the cotter pin (10), nut (11), flat
washer (12), and support mounting (13) from the end of
the gear cover stud (20). 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 (21), support
mount (22), and mount retainer (23) from the radiator
support.
c. Installation.
b. Cleaning and Inspection.
(1) Install the engine on the radiator support
as shown in figure 3-17. Make sure the ground strap
(19) is making good electrical contact between parts.
(2) When you install the tie rod (9) that
connects the radiator support (25) 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 horizontal when the tie rod is installed.
(3) Install the radiator (TM 5-4320-234-12,
para 432).
(4) Install the engine housing (TM 5-4320234-12, para 4-19).
(5) Install the engine on the centrifugal pump
assembly (para 2-11).
WARNING
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
skin to cleaning solvent. Wash
exposed skin thoroughly.
Dry
cleaning solvent (Fed. Spec. P-D680) used to clean parts is
potentially
dangerous
to
personnel and property. Do not
use near open flame or excessive
heat. Flash point of solvent is 100
F. to 138 F. (38 C. to 59 C. ).
(1) Clean the rubber mounting parts with a
cloth dampened with cleaning solvent (Fed. Spec. P-D680). Wash all remaining parts in solvent.
3-21
TM 5-4320-234-34
CHAPTER 4
REPAIR OF ENGINE
Section I. INTRODUCTION
overspeed governor which grounds the magneto to shut
4-1. Description
down operation if engine speed exceeds a preset limit.
The engine is a six-cylinder, four-stroke-cycle, L4-2. Fits, Tolerances, and Wear Limits
head, in-line, water-cooled unit which is designed to run
Table 4-1 lists the fits and tolerances applicable to
on gasoline. It is pressure lubricated by a pump located
the engine. Refer to the table to determine if you must
in the oil pan. It uses magneto ignition and an electrical
replace parts or if continued serviceability of the parts is
starter. Engine speed is controlled by a variable speed
possible.
flyball governor.
The engine is protected by an
Table 4.1. Engine fits tolerances, and wear limits.
Manufacturers
dimensions in
inches
Component points of measurement
Min.
Design clearances
in inches
Max.
Min.
Valve and valve guides.
Intake valves
Cylinder block face-to-guide distance
Outside diameter
Inside diameter
Valve stem diameter
Max.
1-15/32
(3.6717 cm)
0.6565
(1.6412 cm)
0.3422
(0.8555 cm)
0.3406
(0.8515 cm)
0.6575
(1.6437 cm)
0.3432
(0.8580 cm)
0.3414
(0.8535 cm)
Step to guide clearance
0.0008
(0.0020 cm)
0.0026
(0.0065 cm)
Valve-to-tappet clearance
Exhaust valves
Cylinder block face-to-guide distance
Outside diameter
Inside diameter
Valve stem diameter
0.6565
(1.6412 cm)
0.3422
(0.8555 cm)
0.3377
(0.8442 cm)
0.6575
(1.6437 cm)
0.3432
(0.8580 cm)
0.3385
(0.8462 cm)
0.0037
(0.0092 cm)
Valve-to-tappet clearance
Valve tappets
Outside diameter
Maximum bore-to-tappet clearance
No. 3
0.0055
(0.0137 cm)
0.3447
(0.8617 cm)
0.3357
(0.8392 cm)
0.0075
(0.0187 cm)
0.0160 (Hot)
(0.0400 cm)
0.0170 (Cold)
(0.0425 cm)
0.9990
(2.4975 cm)
1.0000
(2.5000 cm)
Tappet bore diameter
No. 2
0.3447
(0.8617 cm)
0.3386
(0.8465 cm)
0.0046
(0.0115 cm)
0.0140
(0.0350 cm)
1.15/32
(3.6717 cm)
Stem-to-guide clearance
Camshaft and bushings
Bearing journal diameter
No. 1
Allowable
wear or
clearance
0.0050
(0.0125 cm)
1.8715
(4.6787 cm)
1.8085
(4.5212 cm)
1.7457
(4.3642 cm)
1.8725
(4.6812 cm)
1.8095
(4.5237 cm)
1.7465
(4.3662 cm)
4-1
1.8705
(4.6762 cm)
1.8075
(4.5187 cm)
1.7447
(4.3617 cm)
TM 5-4320-234-34
Table 4-1. Engine fits, tolerances, and wear limits - Continued
Manufacturer's
dimensions in
inches
Component points of rneasurement
Bearing journal diameter (cont.)
No. 4
Camshaft bushing diameter
No. 1
No. 2
No. 3
No. 4
Design clearances
in inches
Min.
Max.
Min.
1.2465
(3.1162 cm)
1.2475
(3.1187 cm)
1.8745
(4.6862 cm)
1.8115
(4.5287 cm)
1.7495
(4.3737 cm)
1.2495
(3.1237 cm)
1.8755
(4.6887 cm)
1.8125
(4.5312 cm)
1.7502
(4.3755 cm)
2.2505
(5.6262 cm)
Journal-to-bushing clearance
No. 1
No. 2
No. 3
No. 4
Camshaft end play
Connecting rod
Bushing hole diameter
Bearing hole diameter
0.9130
(2.2825 cm)
2.1865
(5.4662 cm)
Bearing thickness
Crank pin diameter
2.1865
(5.4662 cm)
0.0613
(0.0407 cm)
2.0619
(5.1547 cm)
Crankshaft
End thrust
Crank pin diameter
Main bearings
Case hole
Bearing thickness
Crankshaft journal diameter
0.002
(0.0050 cm)
0.002
(0.0050 cm)
0.002
(0.0050 cm)
0.002
(0.0050 cm)
0.005
(0.0125 cm)
0.004
(0.0100 cm)
0.004
(0.0100 cm)
0.004
(0.0100 cm)
0.004
(0.0100 cm)
0.009
(0.0225 cm)
0.0060
(0.0150 cm)
0.0100
(0.0250 cm)
0.0006
(0.0015 cm)
0.0022
(0.0055 cm)
0.0030
(0.0075 cm)
0.0080
(0.0200 cm)
0.0608
(0.1520 cm)
20609
(5.1522 cm)
0.0032
(0.0080 cm)
2.3744
(5.9360 cm)
2.0619
(5.1547 cm)
2.3752
(5.9380 cm)
2.0627
(5.1567 cm)
2.3734
(5.9335 cm)
2.0609
(5.1522 cm)
2.5615
(6.4037 cm)
0.0925
(0.2312 cm)
2.3744
(5.9360 cm)
2.5622
(6.4055 cm)
0.0928
(0.2320 cm)
23752
(5.9380 cm)
0.0920
(0.2300 cm)
2.3734
(2.3734 cm)
Journal-to-bearing clearance
Piston
Ring groove width
1st
1.2455
(3.1137 cm)
2.1870
(5.4675 cm)
0.0616
(0.1540 cm)
2.0627
(5.1567 cm)
Bearing to crankshaft clearance
Main bearing journal diameter
Max.
0.9140
(2.2850 cm)
21870
(5.4675 cm)
Side play
Connecting rod bearing
Bearing hole diameter
Allowable
wear or
clearance
0.0007
(0.0017 cm)
0.1275
(0.3187 cm)
0.1285
(0.3212 cm)
4-2
0.0028
(0.0070 cm)
0.1305
(0.3262 cm)
TM 5-4320-234-34
Table 4-1. Engine fits, tolerances, and wear limits - Continued
Manufacturer's
dimensions in
inches
Component points of measurement
Ring groove width (cont.)
2nd and 3rd
4th
Cylinder bore diameter
Piston fit in bore. Check by pull
on 1/2-inch wide x 0.003-inch
feeler gage
Piston rings
Width
No. 1
No. 2 and 3
No. 4
Design clearances
in inches
Min.
Min
Max.
0.1275
(0.3187 cm)
0.2520
(0.6300 cm)
3.4375
(8.5937 cm)
0.1285
(0.3212 cm)
0.2530
(0.6325 cm)
3.4395
(8.5987 cm)
0.1305
(0.3262 cm)
0.2550
(0.6375 cm)
3.4475
(8.6187 cm)
5 to 10 lb
(2.250 to 4.500 kg)
0.1230
(0.3075 cm)
0.1230
(0.3075 cm)
0.2485
(0.6212 cm)
0.1240
(0.3100 cm)
0.1240
(0.3100 cm)
0.2490
(0.6225 cm)
0.1210
(0.3025 cm)
0.1210
(0.3025 cm)
0.2465
(0.6162 cm)
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
Allowable
wear or
clearance
2.805
(7.012 cm)
0.8591
(2.1477 cm)
0.8595
(2.1487 cm)
Max
0.007
(0.0175 cm)
0.007
(0.0175 cm)
0.007
(0.0175 cm)
0.017
(0.0425 cm)
0.017
(0.0425 cm)
0.017
(0.0425 cm)
0.0035
(0.0087 cm)
0.0035
(0.0087 cm)
0.0030
(0.0075 cm)
0.0050
(0.0125 cm)
0.0055
(0.0137 cm)
0.0045
(0.0112 cm)
2.815
(7.037 cm)
0.8593
(2.1482 cm)
0.8597
(2.1492 cm)
Piston pin fit in piston
Piston pin fit in rod
Valve spring
Weight required to compress to
1-45/64 in. (valve closed)
Weight required to compress to
1-27/64 in. (valve open)
0.8588
0.8067
Light push
0.0002
(0.0005 cm)
0.0006
(0.0015 cm)
47 lb
(21.15 kg)
96 lb
(43.20 kg)
53 lb
(23.85 kg)
104 lb
(46.80 kg)
42 lb
(18.19 kg)
86 lb
(34.40 kg)
Section II. ENGINE REPAIR AND OVERHAUL
NOTE
You can do some engine repair 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 5-4320-234-12, para 4-19).
Remove the engine from its mounting
parts if necessary (para 3-22). Remove
accessories from the engine as required.
4-3. Cylinder Head
a. Removal. Remove the cylinder head and gasket
as shown in figure 4-1. When removing the cylinder
head screws, loosen each a small increment until all are
started. This will help prevent cylinder head distortion.
Repeat for several more small increments until all are
loose.
4-3
TM 5-4320-234-34
Figure 4-1. Cylinder head, exploded view.
4-4
TM 5-4320-234-34
b. Cleaning and Inspection.
(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 (0.0300 cm) in the
center, 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 (0.0075 cm) 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 according to the sequence shown in figure 4-2.
Torque to 35 to 40 foot-pounds (4.840 to 5.532 kgm).
WARNING
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
skin to cleaning solvent. Wash
exposed skin thoroughly.
Dry
cleaning solvent (Fed. Spec. P-D680) used to clean parts is
potentially
dangerous
to
personnel and property. Do not
use near open flame or excessive
heat. Flash point of solvent is 100
F. to 138 F. (38 C. to 59 C. ).
(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. Be
careful that you do not get dirt in the cylinders or water
jacket.
Figure 4-2. Cylinder head capscrew tightening sequence.
(2) Remove the valve chamber cover (7, fig.
4-4. Intake and Exhaust Valves
4-21).
a. General. The intake and exhaust valves
(3) Using a spring lifter, compress the valve
of this L-head engine are mounted in the cylinder block.
spring (5 or 10, fig. 4-3) at each valve (2 or 7) and
They are opened by operation of the camshaft through
remove the valve lock (1 or 6) from each valve that is in
adjustable valve tappets. They are closed by the valve
the closed position. Rotate the engine crankshaft to
springs. The valve stems ride in valve guides which are
close the remaining valves and remove the remaining
pressed into the block. The intake valves seat directly
locks.
in the block. The exhaust valves seat in shrink-fit valve
seat inserts in the block.
b. Removal.
(1) Remove the cylinder head (para 4-3).
4-5
TM 5-4320-234-34
Figure 4-3. Valves and camshaft, exploded view.
(4)
Lift each valve from the top of the
block. Place valves in order in a rack to ensure that you
will reassemble each in the same valve guide from
which it was removed.
(5) Remove the valve rotator (3 or 8), spring
retainer (4 or 9), and valve spring (5 or 10). Remove
the valve tappet assembly (13).
(6) Do not remove the valve guide (11) or
valve seat insert (12) unless inspection indicates that it
is faulty.
4-6
TM 5-4320-234-34
c. Cleaning, Inspection, and Repair.
WARNING
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
skin to cleaning solvent. Wash
exposed skin thoroughly.
Dry
cleaning solvent (Fed. Spec. P-D680) used to clean parts is
potentially
dangerous
to
personnel and property. Do not
use near open flame or excessive
heat. Flash point of solvent is 100
F. to 138 F. (38 C. to 59 C. ).
(1) Clean the valves, valve springs, and
valve tappet assemblies with cleaning solvent (Fed.
Spec.
P-D680); 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 of a
new valve's thickness. You must 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 (0.0050 cm).
(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 (0.8617
cm).
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 (3.5155 cm) from the
top of the block (fig. 4-4).
(7) Check the exhaust valve seat inserts for
cracks or loose mountings. Pull out faulty valve seat
inserts. Replace original valve seats with new 0.010
inch (0.0250 cm) oversized valve seats. Counterbore
the original valve seats to a diameter of 1.3535 to
1.3545 inches (3.3837 to 3.3862 cm). This will provide
the required press fit.
If valve seats had been
counterbored previously, rebore to 0.01 inch (0.0250
cm)
Figure 4-4. Valve guide installation dimensions.
oversize to provide a 0.003 to 0.005 inch (0.0075 to 0.
0125 cm) press fit. Counterbore deeply enough so that
the boring tool will clean up the bottom of the bore to
ensure 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, by 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 into place.
(8) Check the valve springs for cracks and
distortion. Test compression strength with a spring
tester. Compression strength must be as follows:
Length
Load (minimum)
1-45/64 inches (closed) (4.2577 cm)
1-27/64 inches (open) (3.5547 cm)
42 pounds (18.90 kg)
86 pounds (38.70 kg)
(9) Grind the valve seats. The seat angle of
the intake valve is 30°. The seat angle of the exhaust
valves is 45°. Use a dial indicator to check the valve
seat for runout. The total indicator reading must not
exceed 0.002 inch (0.0050 cm). Clean the valve seat
and surrounding area thoroughly after grinding.
(10) After you have refaced and reground the
valves and seats, coat each 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 (0.
1562 to 0.2342 cm), 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 (0.2342 cm), narrow the contact area by
grinding the outside diameter of the seat with a 15°
stone or by grinding the inside diameter of the seat with
a 60°or 75°stone (fig. 4-5). After the
4-7
TM 5-4320-234-34
(1) Operate engine until it reaches operating
temperature.
(2) Disconnect
the
positive
crankcase
ventilation valve and fittings from the valve chamber
cover.
seat area is corrected, touch the seat lightly with the
original grinding stone to remove the burred or
feathered edge.
(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 running at operating
temperature and at idle speed, set the intake valves for
0.014-inch (0.0350 cm) clearance as follows:
(a) Alternately pass a 0.013-inch (0.0325 cm)
and a 0.015-inch (0.0375 cm) flat feeler gage between
the head of the adjusting ,;crew of the tappet (13, fig. 43) and stem of valve (2).
(b) If a 0.013-inch (0.0325 cm) feeler gage
moves freely back and forth in gap when the valve is
not being lifted, and a 0.0015-inch (0.0375 cm) feeler
gage binds at all times, the clearance requires no
adjustment.
(c) If a 0.013-inch (0.0325 cm) 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 you obtain the
proper clearance. The adjustable-type valve lifters have
self-locking adjusting screws that require no lock nuts.
(e) If a 0.015-inch (0.0375 cm) 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-inch
(0.0400 cm) (hot) clearance in the manner described
above, using 0.015 (0.0375 cm) and 0.017 inch (0.0425
cm) feeler gages.
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 that you
install each valve into the guide from which it was
removed.
(3) With the engine stopped, temporarily set
the intake valve-to-tappet clearance to 0.014 inch
(0.0350 cm) and the exhaust valve-to-tappet clearance
to 0.017 inch (0.0425 cm) (cold).
(4) Install the cylinder head (para 4-3).
(5) Operate the engine until it reaches
operating temperature. Adjust valve-to-tappet clearance
as directed in subparagraph e below.
(6) Install the valve chamber cover (7, fig. 421).
4-5. Oil Pan and Filler Blocks
a. Removal.
(1) Remove the drain plug (1, fig. 4-6) and
drain the engine oil into a suitable container. Remove
the oil drain piping (items 2 through 4).
e. Valve Adjustment.
4-8
TM 5-4320-234-34
WARNING
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
skin to cleaning solvent. Wash
exposed skin thoroughly.
Dry
cleaning solvent (Fed. Spec. P-D680) used to clean parts is
potentially
dangerous
to
personnel and property. Do not
use near open flame or excessive
heat. Flash point of solvent is 100
F. to 138 F. (38 C. to 59 C.).
(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 defective oil pan.
(4) Inspect the filler blocks for cracks,
distortion, and other damage; replace damaged filler
blocks.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Oil drain plug
coupling
Nipple
Elbow
Assembled washer screw
Oil pan
Oil pan gasket
Capscrew
Lockwasher
Front filler block seal
Front filler block
Capscrew
Lockwasher
Rear filler block seal
Rear filler block
Oil guard seal
Rear oil guard
c. Installation.
(1) Install the seal (16, fig. 4-6) into the rear
filler block (15) and oil guard (17) 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 (0.
0500 to 0. 0750 cm) above the flat surface of the oil
guard or filler block, using a sharp knife or razor blade.
Make sure the cut is parallel to the flat surface of the
casting.
(2) To replace the neoprene seals (10 and
14) on the filler blocks (11 and 15), 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 you insert the seal into the groove. No
other cement is required.
(3) Lubricate all seals with engine oil. With
the crankshaft in place, the assembled rear oil guard
(17) and jute seal (16) can be rolled into place around
the crankshaft. Position the assembled rear filler block
(15) and seal (14) on the engine block; secure with the
two capscrews (12) and lockwashers (13). Tighten the
capscrews to 15 to 20 foot-pound torque.
Figure 4-6. Oil pan and filler blocks, exploded view.
(2) Remove the 18 assembled washer screws
(5) that secure the oil pan (6) to the block; remove the
oil pan and gaskets (7).
(3) Remove the two capscrews (8) and
lockwashers (9) that secure the front filler block (11) to
the block; remove the filler block and seal (10).
(4) Remove the two capscrews (12) and
lockwashers (13) that secure the rear filler block (15) to
the block; remove the filler block and seal (14), oil guard
seal (16) and oil guard (17).
b. Cleaning and Inspection.
(1) Discard and replace gaskets and seals.
(4) Position the front filler block (11) and seal
(10) on the engine block; secure with the two capscrews
(8) and lockwashers (9). Tighten the capscrews
4-9
TM 5-4320-234-34
to 15 to 20 foot-pounds torque.
(5) Position the gaskets (7) on the oil pan (6).
Install the oil pan and gaskets on the engine block;
secure with the 18 assembled washer screws (5).
Tighten the screws to 12 to 16 foot-pounds torque.
(6) Coat the male threads of the elbow (4)
with thread sealing compound and install the elbow in
the drain pan. Coat the male threads of the nipple (3)
with thread sealing compound and install the nipple in
the elbow. Install the coupling (2) on the nipple, and
install the oil drain plug (1) in the coupling.
(2) Remove the nut (1, fig.
4-7) and
lockwasher (2) securing the engine oil pump to the
bearing cap. Remove the oil pump and flat washer (3).
(3) Remove the screen (4) from the bottom of
the oil pump (5).
b. Cleaning and Inspection.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.)..
4-6. Engine Oil Pump
a. Removal.
(1) Remove the engine oil pan (para 4-5).
(1) Clean all parts with dry cleaning solvent
(Fed. Spec. P-D-680). Allow all parts to dry thoroughly
before reinstallation.
(2) Inspect the screen for holes, clogging, and
distortion. Replace a damaged screen.
(3) Check the fit of the drive shaft in the
pump body. There shall be no excessive play. Replace
the oil pump if the shaft is damaged, or if the play is
excessive.
c. Installation.
(1) Install the screen (4, fig. 4-7) on the
bottom of the oil pump (5).
(2) Position the washer (3) and oil pump (5)
on the main bearing so that the drive gear engages the
toothed portion of the camshaft. Secure the pump with
the nut (1) and lockwashers (2).
(3) Install the oil pan (para 4-5).
4-7. Gear Cover
1. Nut
2. Lockwasher
3. Flat washer
a. Removal and assembly.
(1) Remove the governor from the engine
(para 34).
(2) Remove the water pump from the engine
(TM 5-4320-234-12, para 4-31).
(3) Remove the starting jaw (1, fig. 4-13) 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 capscrews (1, 3, 6, and 10,
fig. 4-8), assembled washer screws (5), nuts (8 and 11),
lockwashers (2, 9, and 12), and copper washers (4 and
7) that secure the gear cover (14) to the engine block;
remove the gear cover and gear cover housing gasket
(15) from the front end plate (19).
4. Screen
5. Engine oil pump
6. Stud
Figure 4-7. Engine oil pump installation.
4-10
TM 5-4320-234-34
Figure 4-8. Gear cover and front end plate, exploded view.
(5) Press the seal (13) from the gear cover.
(6) Remove the assembled washer screw
(16), capscrews (17) and flat washers (18) that secure
the front end plate (19) to the cylinder block; remove the
front end plate and gasket (20).
b. Cleaning and Inspection.
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) 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 4-8, items 1 through 15,
and install the gear cover.
(2) Secure the crankshaft pulley (3, fig. 4-13)
to the crankshaft, using the starting jaw (1) and collar
(2).
(3) Install the governor on the engine (para 36). Time the magneto (TM 5-4320-234-12, para 4-35).
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.).
4-8. Flywheel and Flywheel Housing
a. Removal. Remove the flywheel and flywheel
housing as follows:
(1) Discard and replace all gaskets and seals.
(2) Clean all parts with cleaning solvent (Fed.
4-11
TM 5-4320-234-34
Install the flywheel and recheck runout. If runout still
exceeds 0.008 inch (0.0200 cm) replace the flywheel.
(1) Remove the six nuts (5, fig. 4-13) and
lock washers (6) that secure the flywheel (7) and ring
gear (8) to the crankshaft (36); remove the flywheel.
(2) Remove the capscrews (11, fig. 4-21),
shoulder screws (13), and lockwashers (12 and 14) that
secure the flywheel housing (15) to the block (41);
remove the flywheel housing and gasket.
b. Cleaning, Inspection, and Repair.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.).
(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 you heat the ring gear, be careful not
to damage the flywheel.
Figure 4-9. Checking flywheel runout.
(4) Check flywheel eccentricity by mounting a
dial indicator so that it indicates the inside diameter of
the flywheel counterbore (fig. 4-10); rotate the crankshaft
through one revolution. If the flywheel is eccentric more
than 0.008 inch (0.0200 cm), loosen and retighten the
flywheel mounting bolts and recheck eccentricity. If
eccentricity still exceeds 0.008 inch (0.0200 cm),
replace the flywheel.
(a) Heat the ring gear with a torch and
remove the ring gear from the flywheel.
(b) Heat the replacement ring gear and
cool the flywheel.
(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
achieve a tight fit on the flywheel.
c. Installation.
(1) Position the flywheel housing (15, fig. 421) on the block (41); secure with shoulder screws (13),
capscrews (11), and lockwashers (12 and 14).
(2) Position the flywheel (7, fig. 4-13) on the
crankshaft (36); secure with six bolts (9), lockwashers
(6), and nuts (5). Tighten the nuts to 35 to 40
footpounds (4.8405 to 5.5320 kgm) torque.
(3) Check flywheel runout by mounting a dial
indicator so that it indicates the flat vertical surface of
the flywheel (fig. 4-9); rotate the crankshaft through one
full revolution. Hold pressure against the flywheel to
eliminate crankshaft end play.
If flywheel runout
exceeds 0.008 inch (0.0200 cm), remove the flywheel
and clean the crankshaft flange and flywheel seat.
Figure 4-10. Checking flywheel eccentricity.
(5) Check runout of the flywheel housing face
by mounting a dial indicator so that it indicates the
housing face (fig. 4-11); rotate the crankshaft through
4-12
TM 5-4320-234-34
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.
one revolution. Hold pressure against the flywheel to
eliminate end play. If runout exceeds 0.008 inch
(0.0200 cm), 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 4-11. Checking flywheel housing runout.
Figure 4-12. Checking flywheel housing
eccentricity.
(6) Check eccentricity of the flywheel housing
bore by mounting a dial indicator so that it indicates
(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.
4-9. 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 4-3a).
(2) Remove the engine oil pan (para 4-5a)
and oil pump (para 4-6a). the bore (fig. 4-12); rotate
the engine through one revolution. If the housing bore is
eccentric more than 0.008 inch (0.0200 cm), loosen the
(4) Remove the two cotter pins (10, fig. 4-13)
and nuts (11), that secure a bearing cap (13) to a
connecting rod (20); remove the cap and bearing shells
(14).
4-13
TM 5-4320-234-34
Figure 4-13. Piston, crankshaft, and flywheel, exploded view.
4-14
TM 5-4320-234-34
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 you check the piston fit. 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, the cylinders
are worn oversize, and the block must be replaced.
CAUTION
When you push the piston and rod from the
block, be 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.
NOTE
Disassemble the pistons and piston rods in sets, and
keep the sets together. Also, be sure that you install each
piston and piston rod set into the cylinder from which it
was removed.
(6) Refer to figure 4-13 (items 15 through 20)
and disassemble the piston and connecting rod.
b. Cleaning and Inspection.
WARNING
Dry cleaning solvent, P-D-680 or P-S-661,
used to clean parts is potentially dangerous
to personnel and property. Avoid repeated
and prolonged skin contact. Do not use
near open flame or excessive heat. Flash
point of solvent is 100 F.138 F. (38 C.-59 C.).
(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 lands and distorted grooves, 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.
NOTE
Figure 4-14. Checking piston fit in cylinder bore.
(2) If new pistons (18, fig. 4-13) 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 (2.1487 to
2.1492 cm) diameter. Make sure the final operation is
done with a hone so that 75 percent or 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 (0.0005 cm) and 0.0006 (0.0015 cm) 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) Select pins, bushings and pistons of the
proper size. Heat the pistons and connecting rods and
position the connecting rod in its piston. Install the
piston pin; secure with the piston pin retaining ring (15,
fig. 4-13).
(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 (0.0175 cm), you can file the rings to provide the
required gap. If the ring gap with a new
Pistons and bearings are individually checked and fitted
to the cylinders at reassembly. Before reassembly, check
the cylinder bores as directed in paragraph 4-12c.
(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 inch (0.1520 cm) micrometer.
Thickness must not be less than 0.0608 inch (0.1520
cm) 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.
4-14), using a piece of 0.003-inch (0.0075 cm) feeler
4-15
TM 5-4320-234-34
bearing and journal, and install the bearing cap. Tighten
the connecting rod cap bolts to 40 to 45 footpounds
(5.532 to 6.223 kgm) torque. Rotate the crankshaft to
determine the amount of drag. If clearance is within
tolerance, you will feel a definite drag. 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. 4-13) onto its connecting rod (20) and crank pin
bearing journal; secure with the two bolts (12) and nuts
(11). Tighten the nuts to 40 to 45 footpounds (5.532 to
6.223 kgm) 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 4-5c) and
oil pump (para 4-6c).
(15) Install the cylinder head (para 4-3r).
ring exceeds 0.017 inch (0.0425 cm), the cylinder is
worn oversize and the cylinder block must be replaced.
(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, you will notice a
slight drag 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 ends of the connecting rods
with cloths to prevent damage to the cylinder walls
during installation.
(10) Check the crank pin bearing journal-to
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 40 to 45 foot-pounds (5.532 to 6.223 kgm).
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 0.006 to 0.0022
inch (0.0015 to 0.0055 cm). 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 (1.250 cm) piece of
0.0022inch (0.0055 cm) thick feeler stock between the
4-10. 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 4-3a).
(2) Remove the oil pan (para 4-5a) and oil
pump (para 4-6a).
(3) Remove the gear cover (para 4-7a).
(4) Remove the flywheel and flywheel
housing (para 4-8a).
(5) Remove the pistons and connecting rods
(para 4-9a).
(6) Remove the bolts (24 and 28, fig. 4-13)
that secure the main bearing caps (25, 29, 32, and 34)
to the cylinder block. Loosen the bearing caps by
tapping them with a plastic hammer. Remove the
bearing caps and lower bearings (27, 30, 33, and 35).
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 into the oil hole of the crankshaft as shown
in figure 4-15. Rotate the crankshaft and roll the bearing
shell from the cylinder block.
4-16
TM 5-4320-234-34
(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 0.0920
inch (0.2300 cm), 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 ensure
proper seating of the bearing cap on the block.
c. Reassembly and Installation.
(1) Install the rear oil seal and oil guard as
directed in paragraph 4-5c.
(2) Position the thrust plate (23, fig. 4-13) on
the crankshaft and install the key (22) in the keyway of
the crankshaft, after you make sure that the keyway is
free of burrs. Press the gear (21) onto the crankshaft.
Figure 4-15. Removing upper bearing shell with
angular pin.
(7) Pull the gear (21, fig. 4-13) from the
crankshaft (36). Remove the key (22) and the thrust
plate (23).
b. Cleaning and Inspection.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.).
CAUTION
When you install the crankshaft, make sure
that you aline the timing marks on the
crankshaft with the timing marks on the
camshaft gear. See paragraph 4-11.
(3) Position the upper half of the main
bearings (27, 30, 33, and 35) in the seats in the
crankcase. Position the crankshaft in the bearing shells.
(4) Install the lower half of the main bearings
into the bearing caps (25, 29, 32, and 34).
(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 lockwashers. Tighten
the screws to 85 to 95 foot-pounds (11.75 to 13.13 kgm)
torque.
(c) Remove the bearing and bearing cap.
Check the bearing journal-to-bearing clearance
indicated by the plastigage (fig. 4-16).
(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, you should 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.
4-17
TM 5-4320-234-34
Figure 4-16. Checking bearing clearance with
plastigage.
Figure 4-17. Installing upper bearing half, using
angular pin.
(6) Clearance must be between 0.0007
(0.0017 cm) and 0.0028 inch (0.0070 cm). 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 into
the oil hole in the crankshaft bearing journal (fig. 4-15).
(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 4-17.
(e) Install the replacement bearing half
into 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 (0.0075
cm) feeler gage, 1/2 inch (1.250 cm) long, on the
bearing cap (fig. 4-18).
(c) Install the cap onto the block; secure
with the screws and lockwashers. Tighten the screws to
85 to 95 foot-pounds (11.75 to 13.13 kgm) torque.
(d) Try to turn the crankshaft by hand. If
you cannot turn the crankshaft or if a very definite drag
is felt, bearing-to-bearing journal clearance is within
Figure 4-18. Checking bearing clearance with shim
stock.
tolerance. Remove the shim stock and reinstall the
bearings caps.
(10) After you have installed all main bearings,
use a dial indicator to check crankshaft end play. If end
play is not between 0.003 (0.0075 cm) and 0.008 inch
(0.0200 cm), replace the thrust plate (23, fig. 4-13)
which controls the shaft end play.
(11) Install the pistons and connecting rods
(para 4-9c).
(12) Install the flywheel housing and flywheel
(para 4-8c).
(13) Install the gear cover (para 4-7c).
(14) Install the oil pan (para 4-5c) and oil pump
(para 4-6c).
4-18
TM 5-4320-234-34
(a) Temporarily insert the camshaft (19,
fig. 43) into the block. Check the clearance between
the camshaft bearing journals and camshaft bearings
(20, 21, 22, and 23) with feeler stock cut in strips 1/4
inch (0.6250 cm) wide. Dress the feeler stock with a
stone to eliminate burrs or feathered edges. Clearance
between bearings and journals must be between 0.002
(0.0050 cm) and 0.004 (0.0100 cm) inch.
(b) If clearance exceeds tolerances,
remove the camshaft and replace the camshaft
bearings. New bearings are pre-reamed. Install new
bearings, taking care that you aline the oil holes with the
passages in the block. Be careful that you do not
damage the bearings during installation.
c. Installation.
(1) Lubricate the camshaft bearings with
engine oil and install the camshaft into the block.
Position the thrust plate (18, fig. 4-3) on the camshaft;
secure with two assembled washer screws (17).
CAUTION
When installing the camshaft gear, do not
attempt to seat the gear by tightening the
retaining nut. This procedure 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. 4-19), and drive the gear (15, fig. 4-3) onto the
camshaft.
(15) Install the cylinder head (para 4-3c).
4-11. 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 44b).
(3) Remove the gear cover (para 4-7a).
(4) Remove the nut (14, fig. 4-3) from the
camshaft (19), and pull the gear (15) from the camshaft.
Remove the key (16).
(5) Remove the two assembled washer
screws (17) that secure the plate (18) to the block;
remove the thrust plate.
(6) Pull the camshaft (19) from the block.
b. Cleaning and Inspection.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.).
(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
or cracked keyway, and clogged oil passages. Use
compressed air to check oil passages for clogging.
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 you find any signs of
wear.
(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 (34, fig. 4-21) in the
cylinder block. Replace plug if any leaking is evident
from its circumference.
(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:
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.
Figure 4-19. Timing gears showing alinement
marks.
(3) Check camshaft end play with a dial
indicator. If end play is not between 0.005 (0.0125 cm)
and 0.009 (0.0225 cm) inch, remove the camshaft
timing gear and replace the thrust plate (18, 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 (0.0050
4-19
TM 5-4320-234-34
gear set marked the same as the set you 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 4-7c).
(7) Install the valves and valve tappets (para
4-4c).
(8) Install the cylinder head (para 4-3c).
cm) 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 4-20
and tap the camshaft gear with a hammer. If vibrations
can be felt in the large gear, the clearance is sufficient.
4-12. 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).
(2) Remove the intake and exhaust valves
(para 4-4b).
(3) Remove the oil pan (para 4-5a) and oil
pump (para 4-6a).
(4) Remove the gear cover (para 4-7a).
(5) Remove the flywheel and flywheel
housing (para 4-8a).
(6) Remove the pistons and connecting rods
(para 4-9a).
(7) Remove the crankshaft and main
bearings (para 4-10a).
(8) Remove the camshaft (para 4-11a).
(9) Remove the oil gage rod (1, fig. 4-21)
from the cylinder block, and remove the oil filler cap (3)
from the oil filler nipple (4). If the oil gage rod support
(2) or oil filler nipple is damaged, pull these parts from
the cylinder block.
Figure 4-20. 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 (0.0050 cm) and 0.004-inch (0.0100
cm) undersize (marked U), and 0.002 (0.0050 cm) and
0.004inch (0.0100 cm) oversize (marked 0). Install a
4-20
TM 5-4320-234-34
(10) Remove the cover nuts (5) and gaskets
(6), from the studs (9 and 10). Remove the valve
chamber cover (7) and gasket (8).
(11) Remove the screws (11 and 13) and
lockwashers (12 and 14) that secure the flywheel
housing (15) to the cylinder block; remove the flywheel
housing. If the timing hole cover (17) or felt (18) is
damaged, remove the attaching screw (16) and remove
these pieces. Press out the drive screw pointer (19) and
ring dowel (20) if they are damaged.
(12) Remove the plug (21) and gasket (22);
remove the spring (23), washers (24), and oil pressure
relief valve (25). Remove the two screws (26) and
lockwashers (27) securing the cover (28) to the cylinder
block. Remove the cover and gasket (29).
(13) Press out the sleeve bearing (30) if it is
worn or damaged. Remove the baffles (31 and 32),
plugs (33, 34, and 35), ring dowels (36 and 37), and
studs (38,
4-21
TM 5-4320-234-34
measurement taken about 1/4 inch (0.625 cm) below
the top of the cylinder. The maximum allowable
cylinder wear (the difference between these two
measurements) is 0.008 inch (0.0200 cm).
(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 4-9c), the cylinders are
scratched or scored, or cylinder wear exceeds 0.008
inch, replace the cylinder block.
(5) Inspect the front end 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. Reassembly.
(1) Reassembly is the reverse of removal and
disassembly. Refer to figure 4-21.
(2) When installing the front end plate (19,
fig. 48), tighten the 3/8-inch bolts to 25 to 30 footpounds (3.457 to 4.149 kgm) torque and tighten the
7/16-inch bolts to 50 to 55 foot-pounds (6.915 to 7.606
kgm) torque.
(3) Install the camshaft (para 4-11c).
(4) Install the crankshaft and main bearings
(para 4-10c).
(5) Install the pistons and connecting rods
(para 4-9c).
(6) Install the flywheel and flywheel housing
(para 4-8c).
(7) Install the gear cover (para 4-7c).
(8) Install the oil pump (para 4-6c) and oil pan
(para 4-5c).
(9) Install the intake and exhaust valves (para
44d).
(10) Install the cylinder head (para 4-3c).
(11) See paragraph 3-15 for oil pressure
adjustment procedure.
39, and 40) to ensure that the cylinder block oil and
coolant passages will be properly cleaned.
b. Cleaning
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.).
(1) Remove dirt and grease deposits and all
traces of old gasket material from flywheel housing (15,
fig. 4-21), valve chamber cover (7) and cylinder block
(41), using a putty knife, gasket scraper or wire brush
and dry cleaning solvent (Fed. Spec. P-D-680).
Steam-clean these pieces and boil out the block to
remove deposits from the coolant passages. Blow out
oil passages in the cylinder block and check that they
are not restricted.
(2) Clean all other metal pieces with dry
cleaning solvent (Fed. Spec. P-D-680), and allow all
pieces to dry thoroughly before reassembly.
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
49c).
(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
4-22
TM 5-4320-234-34
CHAPTER 5
REPAIR OF CENTRIFUGAL PUMP ASSEMBLY
5-1. Description
a. The centrifugal pump assembly consists of the
pump, bearing housing, and flexible coupling. The
centrifugal pump is driven by the engine through a
coupling which is secured to the impeller shaft. The
impeller shaft is ball bearing mounted in the bearing
housing. The impeller shaft extends into the pump
housing which is bolted to the bearing housing. The
open-type impeller is keyed to this end of the shaft so
that it rotates with the shaft.
b. The impeller is enclosed in a close-fitting volute
to provide efficient operation. The pump housing
provides the suction and discharge ports. The pump
housing has a replaceable wear plate. This wear plate
is subjected to most of the internal pump wear.
c. Repair consists primarily of replacing the shaft
seal and other damaged parts. 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
and chassis. Overhaul requires removal of the unit to a
workbench.
5-2. Shaft Seal Replacement
Replace a leaking shaft seal as follows:
a. Remove the drain plug (1, fig. 5-1), and drain all
fluid from the pump body.
5-1
TM 5-4320-234-34
Figure 5-1. Centrifugal pump, exploded view.
5-2
TM 5-4320-234-34
b. Use a hoist or other lifting device to support the
weight of the pump body (5). Remove the capscrews
(6, fig. 2-1), nuts (4), and lockwashers (5), that secure
the feet of the pump body to the chassis frame.
c. Remove the nuts (3, fig. 5-1) and lockwashers (4)
that secure the pump body (5) to the bearing housing;
slide the pump body straight out to disengage it from the
remainder of the pump which is secured to the engine.
d. Remove the capscrews (12), and lockwashers (13),
that secure the assembled volute (18) and wear plate
(17) to the seal plate (29); remove the assembled parts.
e. Remove the cone nut (19) that secures the impeller
(20) to the impeller shaft. Use a puller to pull the
impeller from the shaft and remove the key (21).
Temporarily install a plain hexagonal nut on the impeller
shaft to protect the threads while pulling the impeller.
Remove the shims (22 and 23), seal spring (24), and
seal rotating member (25) from the shaft.
f. Remove the nuts (27) and lockwashers (28) that
secure the seal plate (29) to the bearing housing;
remove the seal plate with the assembled seal
stationary member (26). Remove the seal stationary
member from the seal plate.
WARNING
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use near
open flame or excessive heat. Flash point of
solvent is 100 F. to 138 F. (38 C. to 59 C.).
(2) Clean all parts with cleaning solvent (Fed.
Spec. P-D-680) and wipe dry.
(3) 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 damaged
beyond repair.
(4) Inspect the wear plate for wear, scoring,
and distortion. If any damage is evident, replace the
wear plate.
(5) Inspect the volute for cracks, distortion,
internal scoring, and wear; replace if damaged.
(6) Inspect the impeller for cracked, chipped,
worn or broken vanes, damaged or distorted bore or
keyway, and other damage; replace a defective
impeller.
c. Reassembly. Reassemble the pump by reversing
the disassembly sequence. Refer to figure 5-1. Note
the following:
(1) Press the seal stationary member (26)
into seal plate (29) before installing the plate. Lubricate
the impeller shaft lightly with oil and slide the seal
rotating member (25) and spring into place on the shaft.
(2) If the same impeller (20) and wear plate
(17) are reassembled and no clearance change is
indicated, use shims (22 and 23) of the same thickness
as those removed. If a new impeller and/or wear plate
is installed, determine the shim thickness required to
obtain a clearance of 0.010 to 0.020 inch (0.025 to
0.050 cm) between the impeller and wear plate as
follows:
(a) Install impeller (20) on shaft without
shims. Be sure that impeller is seated firmly against the
shaft shoulder.
(b) Install volute (18) with wear plate (17)
assembled, and secure with screws (12) and
lockwashers (13).
(c) Insert a feeler gage into the front
opening of the volute and measure from the face of the
impeller (20) to the face of the wear plate (17).
(d) Select shims (22 and 23) to equal the
dimension obtained less 0.010 to 0.020 inch (0.025 to
0.050 cm) for clearance.
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.
g. Install the seal stationary member (26) into the seal
plate (29); install the seal plate on the bearing housing
with nuts (27) and lockwashers (28).
h. Lubricate the inside diameter of the seal rotating
member (25). Install the rotating member onto the
shaft, and install the seal spring (24). 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.
i. When installing the impeller (20), be sure you install
shims (22 and 23) of the same thickness as those
removed.
j. Reassemble the remainder of the pump by reversing
the disassembly procedure.
When installing the
impeller nut (19) onto the impeller shaft, tighten the nut
to 95 to 110 foot-pounds (13,138 to 15.213 kgm) torque.
Block the impeller with a block of wood to prevent its
rotation when you install the nut (19).
5-3. Centrifugal Pump Overhaul
a. Disassembly. Disassemble the pump following the
sequence of index numbers in figure 5-1.
b. Cleaning and Inspection.
(1) Discard and replace all seals, gaskets,
and packings.
5-3
TM 5-4320-234-34
It is easier to disassemble the pump parts from the
engine than it is to remove the entire pump assembly
before starting disassembly. If the pump is mounted on
the engine, disassemble it per paragraph 5-2 for seal
replacement. Then remove the bearing housing from the
engine and disassemble it. If the pump assembly was
removed from the engine per paragraph 2-9, proceed as
directed below.
(3) After assembly, when using either new or
used parts, recheck the clearance; it must be 0.010 to
0.020 inch (0.025 to 0.050 cm). Check the impeller
shaft for free rotation. It must turn freely without
catching or binding. If binding is evident, disassemble
the pump and correct the condition.
(4) Install the assembled pump and bearing
housing onto the engine and chassis (para 2-9).
(1) Remove
the assembled pump
and
bearing housing from the engine and chassis (para 2-9).
(2) Disassemble the centrifugal pump from
the bearing housing (para 5-3).
(3) Disassemble
the
bearing
housing
assembly in the sequence indicated in figure 5-2.
5-4. Bearing Housing
a. Disassembly.
NOTE
Figure 5-2. Bearing housing, exploded view.
b. Cleaning and Inspection.
(1) Discard and replace all seals, gaskets,
and packings.
(2) Clean the ball bearings as directed in
paragraph 2-7.
Clean all parts in a well-ventilated area.
Avoid inhalation of solvent fumes and
prolonged exposure of skin to cleaning
solvent. Wash exposed skin thoroughly.
Dry cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially dangerous
to personnel and property. Do not use
WARNING
5-4
TM 5-4320-234-34
bearing cap with the capscrews (2) and lockwashers (3),
tightening them evenly in increments until all are secure.
near open flame or excessive heat.
Flash point of solvent is 100 F. to
138 F. (38 C. to 59 C.).
(5) If the pump is to be mounted onto the
engine immediately, it is easier to first mount the
assembled bearing housing onto the engine, and then
assemble the remaining pump parts to the bearing
housing.
If pump assembly is to be assembled
completely for later mounting onto the engine, proceed
as directed in steps (6) and (7) below.
(3) Clean all remaining parts with cleaning
solvent (Fed. Spec. P-D-680); dry thoroughly.
(4) Inspect the ball bearings for scored balls
or races, cracked races, signs of overheating, and
binding operation; replace damaged bearings.
(6) Reassemble the centrifugal pump on the
bearing housing (para 5-3).
(5) Inspect the impeller shaft for distortion,
worn or damaged bearing seats, and damaged retaining
ring grooves, keyways, and threads. You can 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.
(7) Install the assembled pump and bearing
housing on the engine and chassis (para 2-9).
5-5. Pump Performance Test
(6) Inspect the bearing housing for cracks,
distortion, and 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.
After the centrifugal pump has been repaired or
overhauled, connect the pump into a petroleum products
pump flow test setup to check pump output. Provide
adequate supply and discharge facilities. Install a
flowmeter in the discharge line. Fill the pump body with
pumping fluid.
With the engine warmed up and
operating at 2600 rpm, the centrifugal pump must meet
the following performance requirements:
c. Reassembly. Reassemble the bearing housing
assembly by reversing the disassembly sequence.
Refer to figure 5-2. Note. the following:
a. The pump shall prime in not more than 1
minute when subjected to a static suction lift equivalent
to 10 feet using 15 feet of suction line and one elbow.
(1) Press bearings (8 and 10, fig. 5-2) onto
the impeller shaft (11). 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 (7 and 9).
b. The pump shall deliver not less than 980 to
1000 GPM at 60 feet total head.
(2) Press grease seal (12) into the bearing
housing (13) and grease seal (5) into the bearing cap (4)
before installing the shaft and bearings in the bearing
housing.
c. After conducting tests a and b above, test the
pump check valve. Shut off the pump and allow it to set
for not less than 30 minutes. Restart the pump and
determine if the pump immediately primes. Immediate
prime is an indication that the valve prevents siphoning
of fluid from the pump case and is, therefore, in good
condition.
(3) Pack the bearings and bearing cap with
MIL-G-10924 grease; pack the area between the
bearings in the bearing housing three-fourths full of the
same grease.
d. Check the suction and pressure gages against
master gages to verify their accuracy. Output gage
reading must correspond with master gage readings to
within 5 percent of scale reading.
(4) Press the shaft and assembled bearings
into the housing until the bearings are seated. Install the
preformed packing (6) and bearing cap (4). Secure the
5-5
TM 5-4320-234-34
CHAPTER 6
REPAIR OF CHASSIS
6-2. Axle and Suspension System
6-1. Description
a. The chassis assembly is primarily a welded
frame consisting of two longitudinal channels separated
by a series of angle and channel crossmembers. The
angles and channels provide support for mounting the
pump, engine, fuel tank, storage boxes, and remaining
components of the pumping assembly. A drop-down
front leg and two adjustable rear stands provide rigid
support for the chassis. Chock blocks are also stored on
the chassis frame.
a. Removal and Disassembly.
(1) Jack up and block the chassis frame so
that the tires barely touch the floor.
(2) Remove the tires and tubes (TM 5-4320234-12, para 4-51).
(3) Remove the wheel and hub assemblies
(TM 5-4320-234-12, para 4-52).
b. The axle and suspension system is mounted to
the underside of the chassis frame. The suspension
system consists of two shock absorbers and leaf
springs.
WARNING
Make sure that you support the axle
properly
before
removing
the
securing hardware, or injury to
personnel may result.
(4) Remove the nuts (1, fig. 6-1) and
washers (2) securing the axle to the shock absorbers
(11).
6-1
TM 5-4320-234-34
1.
2.
3.
4.
5.
6.
7.
8.
9.
Nut
Washer
Nut
U-bolt
Axle
Washer
Plate
Nut
Lockwasher
10.
11.
12.
13.
14.
15.
16.
17.
Capscrew
Shock absorber
Nut
Capscrew
Nut
Capscrew
Shackle links
Spring
Figure 6-1. Axle and suspension system, exploded view.
(5) Remove the nuts (3) and U-bolts (4)
securing the axle (5) to the leaf springs; remove the
axle.
b. Cleaning and Inspection.
WARNING
(6) Remove the nuts (8), lockwashers (9),
and capscrews (10) that mount the upper ends of the
shock absorbers to the chassis frame; remove the shock
absorbers.
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
(7) Remove the leaf springs (17) by
removing nuts (12 and 14), capscrews (13 and 15), and
shackle links (16).
6-2
TM 5-4320-234-34
skin to cleaning solvent.
Wash
exposed skin thoroughly.
Dry
cleaning solvent (Fed. Spec. P-D-680)
used to clean parts is potentially
dangerous
to
personnel
and
property. Do not use near open
flame or excessive heat. Flash point
of solvent is 100 F. to 138 F. (38 C. to
59 C.).
c. Reassembly and Installation. Reassembly and
installation is essentially the reverse of removal and
disassembly. Refer to figure 6-1. Note the following:
(1) The leaf spring can be installed with
either end toward the front of the chassis.
(2) Make sure you install the shock
absorbers with the proper end up.
(1) Clean the shock absorbers with a cloth
dampened with cleaning solvent (Fed. Spec. P-D-680).
Wipe dry.
(3) Remove blocking and lower unit to the
ground. Rock the unit on its springs to check for free
spring movement and for proper dampening of spring
movement by the shock absorbers.
(2) Steam-clean the axle and springs. If
steam cleaning equipment is not available, flush the
parts with a water-pressure hose. Remove greasy and
gummy deposits with cleaning solvent.
6-3. Chassis Frame
a. Removal and Disassembly.
(3) Clean all remaining parts with cleaning
solvent; dry thoroughly.
(1) Remove the pump and bearing housing
assembly (para 2-9).
(4) Inspect all parts for rust, corrosion,
chipped paint, and distortion.
Remove rust and
corrosion with a metal scraper and wire brush. Prime
and paint bare surfaces.
(2) Remove the engine (para 2-11).
(3) Remove the battery box and tool box
(TM 5-4320-234-12, para 4-54).
(5) Inspect the axle for cracks, distortion, or
damaged threads. Inspect the axle spindle ends for
scored or damaged bearing surfaces.
Replace a
damaged axle.
(4) Remove the fuel tank (TM 5-4320-23412, para 4-22).
(5) Remove the wheel and hub assemblies
(TM 5-4320-234-12, para 4-52).
(6) Inspect the springs for cracked or broken
leaves, distortion, or fatigue. Replace damaged or weak
springs.
(6) Remove the axle and suspension
system (para 6-2).
(7) Inspect the shock absorbers for
distortion, missing or damaged bushings, leaking, and
other damage. Check that the compression stroke
resistance is sufficient. Replace worn or damaged
shock absorbers.
(7) With the chassis frame supported on
blocks, disassemble the chassis in the sequence
indicated in figure 6-2.
6-3
TM 5-4320-234-34
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Chock block
Nut
Lockwasher
Capscrew
Chain
Shackle
Tie down ring
Nut
Lockwasher
Capscrew
Plate nut
Nut
Lockwasher
Capscrew
Plug holder
Nut
Lockwasher
Capscrew
Bumper
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
Cotter pin
Locking pin
Washer
Spring
Cotter pin
Nut
Capscrew
Nut
Lockwasher
Capscrew
Leg
Bracket
Cap
Cotter pin
Chain
Locking pin
Stand
Frame
Figure 6-2. Chassis frame, exploded view.
6-4
TM 5-4320-234-34
(5) Be sure that all remaining parts are
present and in good condition. Replace any missing or
damaged parts.
b. Cleaning and Inspection.
WARNING
(6) Inspect the chassis frame for cracks,
distortion, or broken weldments. Minor straightening of
the frame is permitted. Repair cracked weldments using
arc welding methods. Replace the frame if it is severely
damaged.
Clean all parts in a well-ventilated
area. Avoid inhalation of solvent
fumes and prolonged exposure of
skin to cleaning solvent.
Wash
exposed skin thoroughly.
Dry
cleaning solvent (Fed. Spec. P-D680) used to clean parts is potentially
dangerous
to
personnel
and
property. Do not use near open
flame or excessive heat. Flash point
of solvent is 100 F. to 138 F. (38 C. to
59 C.).
(7) If paint is damaged in any way, remove
damaged paint and sand the areas smooth. Prime and
repaint the bare areas.
c. Reassembly and Installation.
(1) Reassemble the chassis frame as shown
in figure 6-2.
(1) Steam-clean the chassis frame and its
related parts.
If steam-cleaning equipment is not
available, flush off the chassis frame with a waterpressure hose. Remove greasy and gummy deposits
with cleaning solvent (Fed. Spec. P-D-680).
(2) Install the axle and suspension system
(para 6-2).
(3) Install the wheel and hub assembly (TM
5-4320-234-12, para 4-52).
(2) Inspect spring bumpers (19, fig. 6-2) for
cracks, wear, and deterioration; replace if defective.
(4) Install the engine (para 2-11).
(3) Check the fit of the stands (36) in the
sleeves mounted on the frame. The stands must slide
easily through the sleeves.
(5) Install the pump and bearing housing
(para 2-9).
(6) Install the battery box and tool box (TM
5-4320-234-12, para 4-54).
(4) Inspect the front leg (30) and related
parts for distortion, cracks, and damage.
Minor
straightening of the leg is permitted. Replace defective
parts and parts damaged beyond repair.
(7) Install the fuel tank (TM 5-4320-234-12,
para 4-22).
6-5
TM 5-4320-234-34
APPENDIX A
REFERENCES
A-1. Fire Protection
TM 5-4200-200-10
A-2. Lubrication
C91001L
LO 5-4320-234-12
A-3. Painting
TM 9-913
A-4. Radio Suppression
TM 11-483
A-5. Maintenance
TM 9-1870-1
TM 5-4320-234-20P
TM 5-4320-234-12
TM 5-4320-234-34P
Hand Portable Fire Extinguishers for Army Users
Fuel, Lubricants, Oils and Waxes
Pumping Assembly and Engine Lubrication Order
Painting Instructions for Field Use
Radio Interference Suppression
Care and Maintenance of Pneumatic Tires
Organizational Maintenance Repair Parts and Special Tools List, Centrifugal
Pump
Operator and Organizational Maintenance Manual, Centrifugal Pump
Direct Support and General Support Maintenance Repair Parts and Special
Tools
List, Centrifugal Pump
Army Equipment Record Procedures
TM 38-750
A-6. Shipment and Storage
TM 740-90-1
Administrative Storage
A-7. Destruction to Prevent Enemy Use
TM 750-244-3
Procedures for Destruction of Equipment to Prevent Enemy Use
A-1
TM 5-4320-234-34
INDEX
Paragraphs
Pages
A
Adjustment (See specific items)
Administrative storage...................................................................................................................1-6
Alternator:
Bench test...............................................................................................................................3-17g
Brush replacement .................................................................................................................3-17b
Cleaning and inspection .........................................................................................................3-17d
Disassembly ..........................................................................................................................3-17c
Installation .............................................................................................................................3-17h
Reassembly ...........................................................................................................................3-17f
Removal ................................................................................................................................3-17a
Testing ...................................................................................................................................3-17e
Axle and suspension system:
Cleaning and inspection .........................................................................................................6-2b
Reassembly and installation ...................................................................................................6-2c
Removal and disassembly .....................................................................................................6-2a
B
Bearing housing:
Cleaning and inspection .........................................................................................................5-4b
Disassembly ..........................................................................................................................5-4a
Reassembly ...........................................................................................................................5-4c
Bearings, care of ....................................................................................................................2-7
Bearings, main:
Cleaning and inspection .........................................................................................................4-10b
Reassembly and installation ...................................................................................................4-10c
Removal and disassembly .....................................................................................................4-10a
Block, cylinder:
Cleaning ................................................................................................................................4-12b
Installation .............................................................................................................................4-12c
Removal and disassembly .....................................................................................................4-12a
C
Camshaft:
Cleaning and inspection .........................................................................................................4-11b
Installation .............................................................................................................................4-11c
Removal ................................................................................................................................4-11a
Care of bearings ...........................................................................................................................2-7
Centrifugal pump:
Cleaning and inspection .........................................................................................................5-3b
Description .............................................................................................................................1-7, 5-1
Disassembly ..........................................................................................................................5-3a
Reassembly ...........................................................................................................................5-3c
Chassis:
Cleaning and inspection .........................................................................................................6-3b
Description .............................................................................................................................6-1
Reassembly and installation ...................................................................................................6-3
Removal and disassembly .....................................................................................................6-3a
Cleanliness ..................................................................................................................................2-6
Connecting rods and pistons:
Cleaning and inspection .........................................................................................................4-9b
Reassembly and installation ...................................................................................................4-9c
Removal and disassembly .....................................................................................................4-9a
Coupling, flexible:
Cleaning and inspection .........................................................................................................2-10b
Reassembly and installation ...................................................................................................2-10c
Removal and disassembly .....................................................................................................2-10a
I-1
1-1
3-14
3-8
3-10
3-10
3-14
3-13
3-8
3-11
6-2
6-3
6-1
5-4
5-4
5-5
2-28
4-17
4-17
4-16
4-22
4-22
4-20
4-19
4-19
4-19
2-28
5-3
1-1, 5-1
5-3
5-3
6-5
6-1
6-5
6-3
2-28
4-15
4-15
4-13
2-32
2-33
2-31
TM 5-4320-234-34
Paragraphs
Cover, gear:
Cleaning and inspection .........................................................................................................4-7b
Reassembly and installation ...................................................................................................4-7c
Removal and disassembly .....................................................................................................4-7a
Crankshaft and main bearings:
Cleaning and inspection .........................................................................................................4-10b
Reassembly and installation ...................................................................................................4-10c
Removal and disassembly .....................................................................................................4-10a
Cylinder block:
Cleaning .................................................................................................................................4-12b
Installation .............................................................................................................................4-12c
Removal and disassembly .....................................................................................................4-12a
Cylinder head:
Cleaning and inspection .........................................................................................................4-3b
Installation .............................................................................................................................4-3c
Removal ................................................................................................................................4-3a
D
Data plates ...................................................................................................................................1-9a
Data, tabulated .............................................................................................................................1-9
Description (See specific items)
Destruction of Army materiel to prevent enemy use .....................................................................1-5
Differences between models ........................................................................................................1-8
Direct support and general support maintenance
troubleshooting ......................................................................................................................2-4
Disassembly (See specific items)
E
Electrical system, description of ...................................................................................................3-16
Enemy use, destruction of Army materiel to prevent ....................................................................1-5
Engine:
Description .............................................................................................................................4-1
Electrical system ....................................................................................................................3-16
Fits, tolerances, and wear limits .............................................................................................4-2
Installation .............................................................................................................................2-11b
Mounting ................................................................................................................................3-21
Oil filter ..................................................................................................................................3-14
Oil pressure adjustment .........................................................................................................3-15
Oil pump ................................................................................................................................4-6
Oil system ..............................................................................................................................3-13
Removal ................................................................................................................................2-11a
Support ..................................................................................................................................3-22
Torque specifications .............................................................................................................1-9b
Equipment and special tools..........................................................................................................2-1
Errors, reporting of .......................................................................................................................1-3
Exhaust and intake valves:
Adjustment .............................................................................................................................4-4e
Cleaning, inspection, and repair .............................................................................................4-4c
Installation .............................................................................................................................4-4d
Removal ................................................................................................................................4-4b
F
Filler blocks and oil pan:
Cleaning and inspection .........................................................................................................4-5b
Installation .............................................................................................................................4-5c
Removal ................................................................................................................................4-5a
Fits, tolerances, and wear limits ...................................................................................................4-2
Flexible coupling:
Cleaning and inspection .........................................................................................................2-10b
Reassembly and installation ...................................................................................................2-10c
I-2
Pages
4-11
4-11
4-10
4-17
4-17
4-16
4-22
4-22
4-20
4-5
4-5
4-3
1-4
1-4
1-1
1-4
2-1
3-8
1-1
4-1
3-8
4-1
2-34
3-20
3-5
3-7
4-10
3-4
2-33
3-20
1-4
2-1
1-1
4-8
4-7
4-8
4-5
4-9
4-9
4-8
4-1
2-32
2-33
TM 5-4320-234-34
Paragraphs
Removal and disassembly .....................................................................................................2-10a
Flywheel and flywheel housing:
Cleaning, inspection, and repair .............................................................................................4-8b
Installation .............................................................................................................................4-8c
Removal ................................................................................................................................4-8a
Frame, chassis:
Cleaning and inspection ..........................................................................................................6-3b
Reassembly and installation ....................................................................................................6-3c
Removal and disassembly .......................................................................................................6-3a
G
Gaskets and seals ........................................................................................................................2-8
Gear cover:
Cleaning and inspection ..........................................................................................................4-7b
Reassembly and installation ....................................................................................................4-7c
Removal and disassembly .......................................................................................................4-7a
General maintenance ...................................................................................................................2-5
General support and direct support maintenance
troubleshooting ......................................................................................................................2-4
Governor:
Cleaning and inspection .........................................................................................................3-5
Description .............................................................................................................................3-3
Installation .............................................................................................................................3-6
Removal ................................................................................................................................3-4
H
Head, cylinder:
Cleaning and inspection .........................................................................................................4-3b
Installation .............................................................................................................................4-3c
Removal ................................................................................................................................4-3a
I
Identification ................................................................................................................................1-9a
Inspection (See specific items)
Installation (See specific items)
Intake and exhaust valves:
Adjustment .............................................................................................................................4-4e
Cleaning, inspection, and repair .............................................................................................4-4c
Installation .............................................................................................................................4-4d
Removal ................................................................................................................................4-4b
M
Main bearings and crankshaft:
Cleaning and inspection .........................................................................................................4-10b
Reassembly and installation ...................................................................................................4-10c
Removal and disassembly .....................................................................................................4-10a
Maintenance:
Forms and records..................................................................................................................1-2
General ..................................................................................................................................2-5
Repair parts ...........................................................................................................................2-2
Models, differences between ........................................................................................................1-8
Motor, starting:
Brush replacement .................................................................................................................3-19c
Cleaning and inspection .........................................................................................................3-19f
Disassembly ..........................................................................................................................3-19e
Installation .............................................................................................................................3-19h
Pinion clearance check ..........................................................................................................3-19b
Reassembly ...........................................................................................................................3-19g
Removal ................................................................................................................................3-19a
Testing ...................................................................................................................................3-19d
I-3
Pages
2-31
4-12
4-12
4-11
6-5
6-5
6-3
2-28
4-11
4-11
4-10
2-18
2-1
3-3
3-1
3-3
3-2
4-5
4-5
4-3
1-4
4-8
4-7
4-8
4-5
4-17
4-17
4-16
1-1
2-28
2-1
1-4
3-16
3-19
3-18
3-19
3-15
3-19
3-15
3-18
TM 5-4320-234-34
Paragraphs
Pages
O
Oil filter, engine:
Cleaning and inspection .........................................................................................................3-14c
Disassembly ..........................................................................................................................3-14b
Reassembly and installation ...................................................................................................3-14d
Removal ................................................................................................................................3-14a
Oil pan and filler blocks:
Cleaning and inspection .........................................................................................................4-5b
Installation .............................................................................................................................4-5c
Removal ................................................................................................................................4-5a
Oil pressure adjustment, engine ...................................................................................................3-15
Oil pump, engine:
Cleaning and inspection .........................................................................................................4-6b
Installation .............................................................................................................................4-6c
Removal ................................................................................................................................4-6a
P
Pinion clearance check ................................................................................................................3-19b
Pistons and connecting rods:
Cleaning and inspection .........................................................................................................4-9b
Reassembly and installation ...................................................................................................4-9c
Removal and disassembly ......................................................................................................4-9a
Plates, data...................................................................................................................................1-9a
Pump, centrifugal:
Description..............................................................................................................................1-7, 5-1
Installation ..............................................................................................................................2-9b
Performance test ....................................................................................................................5-5
Removal .................................................................................................................................2-9a
R
Radiator:
Cleaning ................................................................................................................................3-9
Description..............................................................................................................................3-7
Inspection and testing .............................................................................................................3-10
Installation ..............................................................................................................................3-12
Removal .................................................................................................................................3-8
Repair ....................................................................................................................................3-11
Radio interference suppression:
Description..............................................................................................................................3-20a
Replacement of suppression components ..............................................................................3-20b
Reassembly (See specific items)
Records, maintenance forms and .................................................................................................1-2
Removal (See specific items)
Repair parts, maintenance ...........................................................................................................2-2
Reporting of errors .......................................................................................................................1-3
S
Scope ..........................................................................................................................................1-1, 3-2
Seals and gaskets .........................................................................................................................2-8
Shaft seal replacement ................................................................................................................5-2
Special tools and equipment ........................................................................................................2-1
Starting motor:
Brush replacement .................................................................................................................3-19c
Cleaning and inspection .........................................................................................................3-19f
Disassembly ..........................................................................................................................3-19e
Installation .............................................................................................................................3-19h
Pinion clearance check ..........................................................................................................3-19b
Reassembly ...........................................................................................................................3-19g
Removal ................................................................................................................................3-19a
Testing ...................................................................................................................................3-19d
Storage, administrative ................................................................................................................1-6
I-4
3-7
3-7
3-7
3-5
4-9
4-9
4-8
3-7
4-10
4-10
4-10
3-15
4-15
4-15
4-13
1-4
1-1, 5-1
2-31
5-5
2-31
3-4
3-4
3-4
3-4
3-4
3-4
3-19
3-19
1-1
2-1
1-1
1-1, 3-1
2-28
5-1
2-1
3-16
3-19
3-18
3-19
3-15
3-19
3-15
3-18
1-1
TM 5-4320-234-34
Paragraphs
Support, engine:
Cleaning and inspection..........................................................................................................3-22b
Installation .............................................................................................................................3-22c
Removal .................................................................................................................................3-22a
Suppression, radio interference:
Description .............................................................................................................................3-20a
Replacement of suppression components ..............................................................................3-20b
Suspension and axle system:
Cleaning and inspection..........................................................................................................6-2b
Reassembly and installation ...................................................................................................6-2c
Removal and disassembly .....................................................................................................6-2a
T
Tabulated data ..............................................................................................................................1-9
Test, pump performance ..............................................................................................................5-5
Testing (See specific items)
Tolerances, fits, and wear limits ....................................................................................................4-2
Torque specifications ....................................................................................................................1-9b
Troubleshooting ...........................................................................................................................2-4
V
Valves, intake and exhaust:
Adjustment .............................................................................................................................4-4e
Cleaning, inspection, and repair .............................................................................................4-4c
Installation .............................................................................................................................4-4d
Removal .................................................................................................................................4-4b
Voltage regulator adjustment ........................................................................................................3-18
W
Wear limits, fits, and tolerances ...................................................................................................4-2
I-5
Pages
3-21
3-21
3-20
3-19
3-19
6-2
6-3
6-1
1-4
5-5
4-1
1-4
2-1
4-8
4-7
4-8
4-5
3-14
4-1
By Order of the Secretary of the Army:
Official:
FRED C. WEYAND
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 12-25A, (qty rqr block no.
maintenance requirements for Petroleum Distribution.
155) Direct and General Support
* U.S. GOVERNMENT PRINTING OFFICE : 1975-665689/18
PIN : 008465 - 000
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