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TM 10-3930-618-34
DEPARTMENT OF THE ARMY TECHNICAL MANUAL
TECHNICAL MANUAL
DIRECT SUPPORT AND GENERAL SUPPORT
MAINTENANCE MANUAL
TRUCK, LIFT, FORK; GASOLINE ENGINE DRIVEN;
PNEUMATIC-TIRED WHEELS; 6000 LB CAPACITY;
168 INCH LIFT; ALLIS-CHALMERS MODEL FP60-24PS;
ARMY MODEL MHE213 FSN 3930-935-7979
This copy is a reprint which includes current
pages from Changes 2 and 3.
HEADQUARTERS, DEPARTMENT OF THE ARMY
MAY 1971
Changes In force: C 2 and C 3
TM 10-3930-618-34
C3
CHANGE
HEADQUARTERS
DEPARTMENT OF THE ARMY
Washington D.C., 26 August 1991
NO. 3
Direct Support and General Support
Maintenance Manual
TRUCK, LIFT, FORK; GASOLINE ENGINE DRIVEN; PNEUMATIC-TIRED
WHEELS; 6000 LB CAPACITY; 168-INCH LIFT; ALLIS-CHALMERS
MODEL FP60-24PS, ARMY MODEL MHE-213, NSN 3930-00-935-7979
TM 10-3930-618-34, 12 May 1971, is changed as follows:
Page 1-1, add the following.
paragraph 1-5b. ”Air cleaner.”
WARNING preceding
Page 1-1, the following paragraph is added after Section
II. "DESCRIPTION AND DATA."
A decal has been developed that warns of NBC
exposure. It is to be positioned in a noticeable place on
or near the air cleaner or air filter housing. You may
order the decal using part number 12296626, CAGEC
19207. Refer to TB 43-0219 for further information. Add
the decal the air cleaner.
If NBC exposure is suspected, all air
filter media should be handled by
personnel
wearing
protective
equipment. Consult your unit NBC
Officer or NBC NCO for appropriate
handling or disposal instructions.
By Order of the Secretary of the Army:
GORDON R. SULLIVAN
General, United States Army
Chief of Staff
Official:
PATRICIA P. HICKERSON
Brigadier General, United States Army
The Adjutant General
Distribution:
To be distributed in accordance with DA Form 12-25E ( Block 2214) Direct and General Support maintenance
requirements for TM 10-3930618-34.
Change in force C2
CHANGE
NO. 2
}
TM 10-3930-618-34
*C2
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D.C., 29 .Nov 1984
Direct Support and General Support
Maintenance Manual
TRUCK, LIFT FORK; GASOLINE ENGINE DRIVEN; PNEUMATIC-TIRED
WHEELS; 6000 LB. CAPACITY; 168-INCH LIFT; ALLIS-CHALMERS
MODEL FP60-24PS, ARMY MODEL MHE-213, NSN 393000-935-7979
TM 10-3930-61834, 12 May 1971, is changed as follows:
Cover. Change "FSN 3930-935-7979" to read "NSN 3930-00-935-7979".
Inside Front Cover. Add safety precautions as follows:
WARNING
DANGEROUS GASES
are generated as a result of operation of this equipment.
ASPHYXIATION
may occur if truck is operated in a closed building without providing adequate ventilation.
DEATH
or severe injury may result if personnel fail to observe safety precautions. Utilize extreme caution,
do not smoke, or use flame in vicinity when servicing batteries. Batteries generate explosive
gas during charging. Always maintain metal-to-metal contact when filling the fuel tank.
Do not smoke or use open flame in vicinity when filling the fuel tank. Do not fill
fuel tank when truck is operating.
LOSS OF HAND OR FINGERS
may occur if adjustments are made on engine while in operation, except for designated adjustments.
Page i. Change "FSN 3930-935-7979" to read "NSN 3930-00-935-7979".
Page 1-1. Chapter 1. Section I. Paragraph 1-3 is superseded as follows:
REPORTING OF ERRORS AND RECOMMENDING IMPROVEMENTS
You can improve this manual by recommending improvements using DA Form 2028
(Recommended Changes to Publications and Blank Forms) or DA Form 2028-2 located
in the back of this manual and mail the form direct to Commander, US Army TankAutomotive Command, ATTN: DRSTA-MB, Warren, MI 48090. A reply will be furnished
to you.
Page 1-1. Paragraph 1-5b(8). After Table 1-2, before Chapter 2 add the following:
(9) Fits, Tolerances, and Wear Limits. Fits, tolerances and wear limits for the engine, transmission, and miscellaneous
items are contained in tables 1-3 (Engine), 1-4 (transmission) and 1-5 (Miscellaneous).
*This Change Supersedes Change 1 dated 6 March 1972.
1
TM 10-3930-618-34
C2
After Page 1-2, in, front of Page 2-1 add the following:
Table 1-3. Engine Fits, Tolerances, and Wear Limits.
Component
CYLINDER SLEEVE
Inside diameter
Diameter of sleeve at machined area
just below flange
Diameter of sleeve at packing ring
location
Sleeve flange-outside diameter
Block to sleeve clearance, lower
diameter
Block to sleeve clearance at machined
area Just below flange
Block to sleeve clearance at sleeve
flange
Clearance of piston skirt with sleeve
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
3.4379
3.4385
3.911
3.913
3.838
3.978
3.840
3.982
desired Clearance
in Inches
Min
Max
0.001
0.005
0.0005
0.0045
0.003
0.006
tight
0.012
0.002
loose
Top surface of cylinder sleeve flange
relative to cylinder block with sleeve
installed
Allowable taper
Allowable out-of-round (when installed)
CYLINDER BLOCK
Counterbore diameter in block for
sleeve flange
Counterbore depth for sleeve flange
Bore in block for sleeve
Top
Bottom
Bore in block for camshaft bearings
Front and intermediate
Rear
Bore in block for main bearings (without baring, cap in place, and capscrews tightened to 120-130 lb ft)
PISTON
Diameter between top and second
ring groove
Diameter at bottom of skirt measured
at right angle to piston pin
Bore for piston pin.
Measurement from center of piston pin
bore to top piston
Clearance of piston skirt with sleeve
Maximum
Allowable
Wear and
Clearance
± 0.002 in.
0.0007 in.
0.001 in.
3.985
0.249
3.990
0.251
3.9136
3.841
3.9155
3.843
2.124
1.374
2.125
1.375
2.6913
2.6920
3.4045
3.4095
3.4365
0.8693
3.4385
0.8696
1.995
2.000
0.0006
tight
2
0.002
loose
TM 10-3930-618-34
C2
Table 1-3. Engine Fits, Tolerances, and Wear Limits-Continued.
Component
PISTON PIN
Length
Diameter of pin
Fit at pin in piston, room temperature
Inside diameter of connecting rod
bushing installed
Piston pin to connecting rod bushing
clearance
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
2.738
0.8591
0.8593
MAIN BEARING
Inside diameter (with capscrews
tightened to 120-130 lb ft)
Diameter of crankshaft main hearing
journals
Bearing to journal (with capscrews
tightened to 120-130 lb ft)
Overall length of main bearing
Front
Intermediate
Center
Rear
Bearing wall thickness (standard
bearing)
Bore in cylinder block (without bear
ing, cap In place, and capscrews
tightened to 120-130 lb ft)
Maximum
Allowable
Wear and
Clearance
2.753
0.8593
0.0001
0.0005
loose
0.0000
0.0006
loose
0.8596
PISTON RINGS
Gap between end--fitted
Clearance of rings in grooves:
Top compression
2nd compression (intermediate)
3rd oil control
4th oil control
CRANKSHAFT
Journal diameter for connecting rods
Journal diameter for main hearings
Width between connecting rod journal
checks
Width of main hearing journals:
Front bearing
Intermediate hearings
Center hearing
Rear bearing
Crankshaft end clearance
Fit of crankshaft gear on crankshaft
(tight)
desired Clearance
in Inches
Min
Max
0.011
2.1214
2.4984
2.1224
2.4994
1.500
1.504
1.557
1.308
1.878
1.567
1.316
1.882
2.000
2.5007
2.5024
2.4984
2.4994
1.057
1.057
1.874
1.708
1.067
1.067
1.876
1.718
0.0948
0.0953
2.691
2.69 20
3
0.002
0.0015
0.0015
0.001
0.004
0.0035
0.0035
0.003
0.002
0.008
0.001
0.003
0.0013
0.0040
0.014
0.007
TM 10-3930-618-34
C2
Table 1-3. Engine Fits, Tolerances, and Wear Limits-Continued.
Component
CONNECTING ROD BEARINGS
Inside diameter of bearing (with nuts
tightened to 40-50 lb ft)
Diameter of crankshaft connecting rod
journals
Connecting rod bearing to journal
clearance (with nuts tightened to
40-50 lb ft)
Overall length of connecting rod
bearings
Bearing wall thickness (standard
bearing)
CONNECTING RODS
Length (center to center)
Inside diameter of bushing (finished
bore)
Outside bore of bushing
Bearing bore (without bearing, caps
in place and nuts tightened to
40-50 lb ft)
Connecting rod bearing to crankshaft
journal clearance (with nuts
tightened to 40-50 Ib ft)
Connecting rod width at lower end
Side clearance to crankshaft cheek
Piston pin diameter
Piston pin to connecting rod bushing
clearance (loose)
Bore in connecting rod for piston pin
bushing
EXHAUST VALVE
Valve lift (at valves)
Valve lift (at cam)
Seat angle
Seat width (contact)
Valve clearance (cold)
Valve clearance (engine coolant at
normal operating temperature)
Overall length
Head diameter
Stem diameter
Inside diameter of valve guide (finish
room after assembly)
Stem to guide clearance
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
2.1239
2.1264
2.1214
2.1224
1.180
1.190
0.0623
0.0628
7.748
7.762
0.8593
0.9175
0.8596
0.9195
2.2495
2.2600
1.495
0.003
0.8591
1.497
0.009
0.8593
0.913
desired Clearance
in Inches
Min
Max
0.0015
0.0040
0.0015
0.0040
0.0000
0.0005
Maximum
Allowable
Wear and
Clearance
0.914
0.428 in.
0.312 in.
45 degrees
31/2 in.
0.014 in.
0.012 in.
4-3/8 in.
1.307
0.3405
1.317
0.3415
0.343
0.344
0.0015
4
0.0035
TM 10-3930-618-34
C2
Table 1-3. Engine Fits, Tolerances, and Wear Limits-Continued.
Component
INTAKE VALVE
Valve lift (at valve)
Valve lift (at cam)
Seat angle
Valve seat width (contact)
Valve clearance (cold)
Valve clearance (engine coolant at
normal operating temperature)
Head diameter
Overall length
Stem diameter
Inside diameter of valve guide (finish
room after assembly)
Stem to guide clearance
VALVE SPRING
Free length
Load (small)
Load (large)
VALVE SEAT INSERTS
Seat angle (intake & exhaust)
Seat width (intake)
Seat width (exhaust)
Outside diameter not installed (intake)
Outside diameter not installed (exhaust)
Bore in cylinder for insert (intake)
Bore In cylinder for insert (exhaust)
Press fit (intake & exhaust) (tight)
Runout (intake & exhaust)
VALVE GUIDES
Length
Inside diameter (finish ream after
assembly)
Stem to guide clearance
Guide standout (top of guide is
positioned above the head cover
gasket surface)
ROCKER ARMS
Inside diameter of rocker arm
(finished bore)
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
desired Clearance
in Inches
Min
Max
Maximum
Allowable
Wear and
Clearance
0.430 in.
0.312 in.
45 degrees
1/16 in.
0.012 in.
0.010 in.
1.496
1.606
0.3406
0.8416
0.843
0.0016
0.S44
0.0035
42 lb
122 lb
47 lb
131 lb
4-3/8 in.
2-3/32 in.
1-27/32 in.
1-13132 in.
46 degree
1/16 in.
3/32 in.
1.597
1.378
1.5935
1.3745
0.0026
1.598
1.379
1.5945
1.7655
0.0046
0.002 in.
TIR
2-11/32 in.
0.343
0.844
0.0015
0.0035
7/32 in.
0.842
0.844
5
TM 10-3930-618-34
C2
Table 1-3. Engine Fits, Tolerances, and Wear Limits-Continued.
Component
Outside diameter of rocker arm shaft
Clearance rocker arm shaft to rocker
arm
Rocker arm ratio
CAMSHAFT
Inside diameter of camshaft bearings
(when installed)
Front and Intermediate
Rear
Outside diameter of camshaft journals
Front and intermediate
Rear
Bearing-to-journal-running
clearance
Outside diameter of camshaft bearings
Front and intermediate
Rear
Bore in block for camshaft bearings
Front and intermediate
Rear
Fit of camshaft bearings in bore of
cylinder block
Front and intermediate (tight)
Rear (tight)
Overall width of camshaft bearings
Front
Intermediate
Rear
Camshaft end clearance
Camshaft gear width
Specified thickness of thrust collar
Fit of camshaft gear on camshaft (tight)
VALVE LIFTER
Bore in cylinder block for lifter
Outside diameter of valve lifter stem
Fit of lift- in bore
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
0.8405
2.004
1.254
1.998
1.248
1.999
1.249
2.1285
1.3790
2.1305
1.3805
2.124
1.374
2.125
1.375
0.5615
0.5600
0.5006
0.001
0.0035
0.007
1.41:1
0.0020
0.0060
0.0065
0.002
0.004
0.006
0.0055
0.003
0.008
0.001
0.003
0.0010
0.0025
0.001
0.005
0.001
0.002
0.002
0.004
1-1/8 in.
7/8 in.
1 in.
0.014
1 in.
0.167
0.5625
0.5605
GEAR TRAIN
Backlash between mating gears
LUBRICATING OIL PUMP
Radial clearance gears to pump housing
End clearance-pump gears
Bore in oil pump housing for
driveshaft
Maximum
Allowable
Wear and
Clearance
0.8410
2.001
1.251
0.165
desired Clearance
in Inches
Min
Max
0.5015
6
0.0035
0.006
TM 10-3930-618-34
C2
Table 1-3. Engine Fits, Tolerances, and Wear Limits-Continued.
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
Component
Bore in oil pump housing for idler
shaft
Diameter of drive and idler gear shaft
Clearance-driveshaft to housing bore
Clearance-idler shaft to housing bore
Backlash-pump gears
0.500
0.4990
desired Clearance
in Inches
Min
Max
0.501
0.4995
DISTRIBUTOR
Point gap
0.0010
0.0020
0.004
0.0025
0.0025
0.010
0.022
0.022
SPARK PLUGS
Point gap
0.0020
0.016 in.
(min)’
0.025 in.
TIMING GEARS
Clearance camshaft end
Maximum permissible end clearance
STARTING MOTOR
Brush spring tension
Bushing clearances
Commutator-end frame
Center plate and drive housing
0.003
0.008
0.008
35.0 oz
0.009
0.005
0.0013
0.0015
ALTERNATOR
Belt adjustment (amount
deflection)
Test force
112 in.
inward
10 lb
GOVERNOR
Spring
Length
Test force
Outside diameter
Max load
Number of coils
Component
Maximum
Allowable
Wear and
Clearance
2.25
25 psi
15/16
100 lb
10-1/2
30 psi
Table 1-4. Transmission Fits, Tolerances, and Wear Limits.
Manufacturer’s
Dimensions and
Tolerances in
desired Clearance
Inches
in Inches
Min
Max
Min
Max
TRANSMISSION
Forward and reverse gear diameter
OD
ID
Idler gear diameter
4.148
1.834
4.594
4.164
1.839
4.600
7
0.005
0.005
0.009
0.009
Maximum
Allowable
Wear and
Clearance
0.005
0.005
TM 10-3930-618-34
C2
Table 1-4. Transmission Fits, Tolerances, and Wear Limits-Continued.
Component
Output gear diameter
ID
OD
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
1.126
1.995
1.130
2.000
TORQUE CONVERTER
Backlash-input shaft to pump
Major diameter
Root diameter
Backlash-input shaft to flywheel
Major diameter
Root diameter
0.002
1.486
1.380
0.004
0.886
0.780
0.004
1.489
1.390
0.008
0.889
0.790
CLUTCH
Maximum allowable dish or warp
Retractor spring
Free length
Outside diameter
0.355
1.865
0.375
50 pi
70 psi
TRANSMISSION CONTROL VALVE
Bypass valve-relieves
Bypass valve spring
Free length
Length test force applied
Outside diameter
Pressure regulating valve
external (500 rpm)
relieves
Swing, pressure regulating valve
Free length
Outside diameter
Regulator valve-relieves
inching valve-relieves
Inching valve spring
Free length
Test force
Length-test force
applied
Dump valve-relieves
Dump valve spring
Free length
Selector valve-pressure
(500 rpm)
Selector valve-pressure
(200 rpm)
Pump pressure (500 rpm)
Pump pressure (2000 rpm)
2.043
1.386
0.417
22-1/2
psi
27-1/2
psi
2-1/16
2-1/8
0.523
100 psi
100 psi
80 psi
O psi
2.052
13.5 lb
1-25/64
in.
2.072
3 psi
1.047
15 psi
27 psi
70 psi
15 psi
140 psi
87 psi
30 psi
60 psi
8
desired Clearance
in Inches
Min
Max
Maximum
Allowable
Wear and
Clearance
TM 10-3930-618-34
C2
Table 1-4. Transmission Fits, Tolerances, and Wear Limits-Continued.
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
Component
DOUBLE REDUCTION GEAR TRAIN
Bevel gear to pinion backlash
0.0060
STEERING CYLINDER
Diameter of rod
Length-cylinder closed
Length-rod extended
0.875
15.65
23.65
desired Clearance
in Inches
Min
Max
0.0100
Maximum
Allowable
Wear and
Clearance
0.0040
Table 1-5. Miscellaneous Fits, Tolerances and Wear Limits.
Component
Manufacturer’s
Dimensions and
Tolerances in
Inches
Min
Max
BRAKE DRUM
Diameter
12.495
12.505
TILT CYLINDER
Rod diameter
1.243
1.247
LIFT CYLINDER
Rod diameter
3.194
3.202
Page 2-1. Chapter 2. Section II. Table 2-1. Malfunction
1. Change Corrective action from "Valves not seating
properly. Either adjust (TM 10-3930618-20) or grind
valves (para 3-23)" to read "Valves not seating properly.
Either adjust (para 3-20.1b) or grind valves (para 3-23).".
Page 2-6. Paragraph 2-9a(3) is superseded as
follows:
(3) Drain engine cooling system and remove
radiator and hose connections (para 3-6.1).
Page 2-9. Paragraph 2-9e(8) is superseded as
follows:
(8) Install radiator and hoses. Pour coolant
into engine cooling system and check for leaks.
Refer to Cooling System section, (para 3-6.1).
Page 2-9. Paragraph 2-9e(9) is superseded as follows:
(9) Install counterweight (para 3-6.1) Page 2-9
Paragraph 2-10b(l) is superseded as follows:
(1) Remove radiator grille (para 3-6.1b).
desired Clearance
in Inches
Min
Max
Maximum
Allowable
Wear and
Clearance
12.465
Page 2-12. Paragraph 2-12 is rescinded.
Page 2-12. Figure 2-6 is rescinded.
Page 3-7. Paragraph 3-6b is superseded as follows:
b. Removal and Installation. Refer to para 3-6.1
and para 3-6.1
Page 3-7. Paragraph 3-6c is superseded as follows:
c. Cleaning and Inspection. Refer to paragraph 36.1
Page 3-7. After paragraph 3-6, before Section III add the
following:
3-6.1. Radiator
a. Inspection and External Cleaning.
(1) Remove the counterweight.
Refer to
figure 3-6.1.
WARNING
Use lifting device, with a 4000 Ib
capacity, for removing counterweight
from truck.
9
TM 10-3930-618-34
C2
Figure 3-6.1. Counterweight, installed view.
WARNING
(5) Tighten hose clamps.
(6) Inspect radiator core and hoses for leaks.
(7) Inspect hoses for cracks or deterioration.
b. Removal. Refer to figure 3-6.2 and remove
the radiator as follows:
(1)
Remove the side panels and raise the
seat.
(2) Remove the radiator cap, open the drain
cocks and drain the cooling system.
(3) Disconnect upper and lower hoses from the
radiator.
(4) Disconnect the converter oil cooler lines at
the radiator.
(5) Remove the radiator grille and panel.
(6) Remove the four screws (two on each side
of the radiator) that secure the radiator to the
mounting bars.
(7) Remove radiator.
c. Installation. Reverse procedures in b above.
Make sure that all lines and hoses are tight.
d. Draining and Refilling.
(1) To drain the cooling system remove the
radiator cap and open the drain cocks (fig. 3-6.3)
and (fig. 3-6.4). If the cooling system is not to be
HIGH VELOCITY AIR
Compressed air, used for cleaning
purposes, will not exceed 30 psi.
Safety glasses must be used when
cleaning parts with compressed air.
Failure to do so could cause
SERIOUS INJURY to your EYES and
possible BLINDNESS. If you hurt
your eyes or if a foreign object is
blown into your eyes, seek medical
attention immediately.
(2) Remove
dirt,
insects,
and
other
obstructions lodged in the fins by directing compressed a
or a stream of pressurized water at the core from the
front (engine side). Do not use steam, gasoline fuel oil,
or kerosene.
(3) Straighten bent fins using a piece of wood
or a blunt instrument. Be careful not to puncture the
tubes.
(4) Inspect radiator mounts and tighten
necessary.
10
TM 10-3930-618-34
C2
Figure 3-6.2. Radiator, installed view.
refilled immediately, attach a notice to the steering wheel
to warn personnel that the cooling system has been
drained.
(3) Use soft water in the cooling system
wherever possible. Add antifreeze or corrosion inhibitor
to the water as applicable.
(4) To fill the cooling system, close the drain
cocks and pour coolant into the radiator filler opening
until the coolant reaches the bottom of the filler neck.
Then start the engine and let it idle until the thermostat
opens.
(2) After draining and before refilling, clear
and flush the cooling system (TM 10-3930-618-20).
Pressure flush the radiator (TM 10-3930-618-20) if
overheating cannot be corrected by normal cleaning and
flushing.
11
TM 10-3930-618-34
C2
3-20.1. Valves
a. General. The valves are of the overhead type:
and adjustment may be made after removing the rocker
arm cover on top of engine. Maintaining correct valve
clearance is very important. Insufficient valve clearance
will cause burning of the valves and valve seats if
allowed to continue. Excessive valve wear will result in
faulty engine operation and valve and lifter wear will
cause rapid wear of the valve operating mechanism.
b. Adjustment.. Adjust the valve clearance as
follows:
(1) Operate the engine until it reactors normal
operating temperature.
(2) Stop the engine and disconnect the high
tension wire from the ignition coil to prevent accidental
starting.
(3) Thoroughly clean the valve cover and
surrounding area and remove the valve cover.
(4) Crank the engine with the starter motor
until both valves of No. 1 cylinder are closed and the
push rods are at the lowest position on their respective
cams.
(5) Using a flat feeler gage (fig. 3-20.1) of
0.012 inch thickness, check the clearance between the
exhaust valve stems (engine hot) and their respective
rocker arms. The feeler gage should pass through with
a slight drag. Repeat this process on the intake valves
using feeler gage thickness of 0.010.
(6) If adjustment is necessary, loosen the
locknut and obtain proper clearance by turning the
adjusting screw. Turning the adjusting screw clockwise
will decrease the clearance; counterclockwise will
increase the clearance.
(7) Tighten the locknut and then recheck the
clearance to make certain no change occurred.
(8) Repeat the above procedure on the
remaining cylinders following the firing order of the
engine (1-5-3-6-4) .
(9) Connect the high tension wire to the
ignition coil and start the engine.
(10)
Run
the
engine
at
operating
temperature, pass the feeler gage back and forth
between the exhaust rocker arms and valve stems and
check for 0.012-inch thickness. A slight drag will be felt,
followed by a tightening which will momentarily pre vent
moving the feeler gage. Repeat this process for the
intake valves and check for 0.010-inch thickness. Stop
the engine and correct any improperly adjusted
clearances. Repeat step (10) above
Figure 3-6.3. Drain valve, radiator.
Figure 3-6.4. Drain valve, block.
Page 3-12. Paragraph 3-9d(1). Change "P-S-661" to
read “P-D-680".
Page 3-15. Paragraph 3-12a(3). Change "(ref. TM 103930-618-20)"' to read "(para 3-6.1)".
Page 3-26. Paragraph 3-16(4)(b). Change "P-S-661" to
read "P-D-680".
Page 3-35. Paragraph 3-20(2)(a)1. Change "(TM 103930-i8-"20)" to read "(para 3-20.1)".
Page 3-25. After Paragraph 3-20, before Paragraph 3-21
add the following:
12
TM 10-3930-618-34
C2
Failure to follow this procedure could
cause serious injury. Should you be
struck by a high pressure oil stream,
seek medical help immediately.
Page 5-10. Paragraph 5-7b. Change "Refer to TM 103930-618-20 for removal procedure" to read "Refer to
paragraph 5-7.2 for removal procedure."
Page 5-10. After Paragraph 5-7, before Paragraph 5-8
add the following:
5-7.1. General
The steering system consists of the power steering unit,
power steer cylinder, and the steering axle assembly.
The steering axle is located beneath the engine at the
rear of the truck. The steering unit is mounted in the
truck chassis in front of the operator.
5-7.2. Power Steering Cylinder
a. Inspection. Inspect the steering cylinder, for
leaks or damaged condition. Replace power steer
cylinder if damaged.
b. Removal. Refer to figure 5-8.1 and remove the
power steering cylinder.
(1) Disconnect hydraulic lines at the cylinder.
Plug lines to keep out foreign matter.
(2) Remove bolt, cotter pin, and pin and
remove cylinder from bracket.
(3) Loosen locknut.
(4) Rotate the cylinder to remove it from fitting
on steering axle pivot arm.
c. Installation.
(1) Reverse procedure as outlined in above.
(2) Refill and bleed hydraulic cylinder before
tightening hydraulic lines.
(3) Operate the cylinder through several
cycles and check for leaks before final installation of pin
and cotter pin.
Paragraph 5-9. Steer Wheel Bearings is deleted.
Page 5-13. After Paragraph 5-10, before Section II add
the following:
Figure 3-20.1. Adjusting valve clearance.
(11) Install the valve cover, making certain that
the cover gasket is in good condition and positioned properly to prevent oil leakage.
Page 3-40. Paragraph 3-21(2)c. Change "(Spec P.S661)" to read "(Spec P-D-680)".
Page 3-45. Paragraph 3-23b(1)a. Change "(TM 103930-618-20)" to read "(para 3-20.1)".
Page 3-47. Paragraph 3-23d(7). Change "(TM 10-3930618-20)" to read "(para -3-20.1)".
Page 3-49. Paragraph 3-24b(1)(a). Change "(TM 103930-618-20)" to read "(para 3-6.1)".
Page 3-50.- Paragraph 3-25a(1). Change "(TM 103930618-20)" to read "(para 3-6.1)".
Page 4-1. Chapter 4. Section I. After the title "Section
I. HYDRAULIC SYSTEM", before paragraph 4-1 add
the following:
5-10.1. Tie Rods
a. Removal.
(1) Loosen the adjusting plug and disconnect
the tie rod from the pivot arm.
(2) Remove the nuts from the ball socket on
the opposite end of the rods and remove the tie rods
from the truck.
WARNING
Hydraulic oil under pressure. 2500
PSI pressure is used to operate this
equipment. Never disconnect any
hydraulic lines or fittings without
dropping the pressure to zero.
Operate all hydraulic levers with
vehicle turned off to release any
pressure.
13
TM 10-3930-618-34
C2
Figure 5-8.1. Power steering cylinder, installed view.
b. Disassembly. To disassemble tie rods, remove the
adjusting plugs and withdraw the internal parts (fig. 5-10.1
If desired, unscrew the ball sockets. Note the
position of each part to assure proper assembly.
WARNING
Dry cleaning solvent, SD-2 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 59° C
(138° F).
c. Cleaning and Inspection. Wash all parts in SD-2
and dry with compressed air. Inspect for damaged
springs and ball seats. Inspect for defective threads.
d. Repair and Replacement. Replace defective
parts and lubricate.
e. Reassembly. Reverse procedures in b above.
f. Installation. Reverse procedure in a above.
Page 5-16. After para 5-11. General" title add the following:
1 Tie rod
2 Plug
J Seat
4 Sprint
5 Washer
6 Pin, cotter
7 Fitting, lubrication
WARNING
8 Tube assembly
9 Nut
10 Fitting, lubrication
11 Socket
12 Cover
13 Nut
14 Pin, cotter
During asbestos fiber pad removal
use wet process only. Sander, dry
brush and compressed air create
dangerous dust hazards to your
health.
Inhaled asbestos dust
remains
permanently
in
your
breathing system.
Figure 5-10.1. Tic rod, exploded view.
14
TM 10-3930-618-34
C2
Page 5-16. Paragraph 5-12a. Change "a. Removal.
Refer to TM 10-3930-618-20" to read "a. Removal.
Refer to paragraph 5-12.1".
Page 5-16. After Para. 5-12 before Para. 5-13 add the
following:
(c) Remove the floor plate to expose
the brake assembly.
(d) Remove the yoke pin and detach the
yoke from the brakeshoe actuating lever (fig. 5-12.2).
(e) Remove the two cable clamps and
remove the cable.
5-12.1. Hand Brake Lever, Cable and Linkage
a. Removal
(1) Level assembly. Refer to figure 5-12.1
and remove the lever assembly as follows:
(a) Disengage the handbrake.
(b) Remove the 2 screws and
lockwashers from the cover and remove the cover.
Figure 5-12.2. Handbrake lower cable yoke adjustment.
b. Installation.’ Reverse procedure in a above.
Make final adjustment as instructed in c below. Yoke
adjustment should be such as to allow approximately 5
turns on the adjusting knob for future periodic
adjustment.
c. Adjustment. Up to a point, the adjusting knob on
the handbrake lever can be used to compensate for
brake lining wear. When the adjusting knob will no
longer provide the necessary brake adjustment, and
sufficient brake lining still remains, further adjustment
can be made at the lower cable yoke.
(1) Adjustment using the hand brake lever
adjusting knob:
(a) Set the lever in fully released
position.
(b) Remove the setscrew from the
adjusting knob.
(c) Turn the adjusting knob one or two
turns clockwise, check adjustment by engaging the
brake.
(d) Repeat step (c) if necessary and
reinstall the setscrew in the adjusting knob.
(2) Adjustment of lower cable yoke.
(a) Disengage the brake and remove
the setscrew from the adjusting knob. Turn the adjusting
knob 4 or 5 turns counterclockwise.
(b) Remove the floor plate and remove
the pin from the lower cable yoke. Loosen the yoke
locknut figure 5-12.2.
Figure 5-12.1. Handbrake lever, installed view.
(c) Remove the small setscrew from the
adjusting knob on the lever and turn the knob
counterclockwise to disengage the brake cable.
(d) Remove the 2 capscrews securing
the lever assembly to the truck.
(2) Brake cable.
(a) Perform (1) (a) and (b) above.
(b) Remove the pin and detach the
cable clevis from the lever assembly.
15
TM 10-3930-618-34
C2
(c) Turn the yoke 3 or 4 turns clockwise
to shorten the cable length.
(d) Install the yoke on the brake lever
and check adjustment by engaging the brake. Readjust
as necessary to prevent the brakeshoes from dragging
when disengaged.
(e) Tighten the yoke locknut and install
the pin.
(f) Install and tighten the setscrew in
the adjusting knob.
512.3. Brake Master Cylinder
a. Removal. Refer to figure 5-12.3 and remove the
master cylinder assembly as follows:
(1) Remove the floor plate.
(2) Disconnect the electrical wires at the
stoplight switch.
(3) Remove the power booster (TM 10-3930618-20).
(4) Remove the clevis pin holding the pushrod
to the brake pedal.
(5) Remove the screws holding the master
cylinder assembly to the inside of the frame and remove
the cylinder.
c. Bleeding the Brake Hydraulic System. The fluid
in the brake hydraulic system must form a "solid"
column. To do this, the system must be bled of all air or
other gases. Bleeding of the brake system is required
each time the system is drained and refilled with new
fluid; if some part of the system has been disconnected
for any reason; if the fluid level in the master cylinder is
allowed to decrease to a point where air enters the
system; if the air has entered the system due to a
defective master cylinder or wheel cylinders; or if the
brake pedal feels spongy. There is a bleeder screw on
each wheel cylinder and on the power hooster. To bleed
the system, proceed as follows:
(1) Fill the master cylinder to the proper level
(3/8- to 1/2-in. from the reservoir top).
(2) If a refiller or pressure bleeder is used,
place the proper adapter in the master cylinder fillercap
opening and install the refiller or pressure bleeder.
(3) Install a bleeder hose on the bleeder
screw of either wheel cylinder. Submerge the loose end
of the hose in brake fluid in a glass jar.
(4) Open the bleeder screw one turn.
(5) If a pressure bleeder is used, permit the
fluid to drain from the bleeder hose until no bubbles
appear in the fluid. Then close the bleeder screw.
(6) If manual bleeding is being employed,
slowly depress the brake pedal to the stroke limit, close
the bleeder screw, and then release. Repeat until no
bubbles escape from the bleeder hose. Keep the pedal
depressed after the final stroke and quickly close the
bleeder screw so that no air enters the system.
NOTE
Manual bleeding quickly depletes the
fluid supply in the reservoir.
Continually check the fluid level and
keep the reservoir at least 1/2 full at
all times or air will enter system.
(7) Repeat the bleeding procedure at the
remaining wheel cylinder and then at the power booster.
(8) When the bleeder operation is complete
re-fill the master cylinder reservoir to the proper level.
CAUTION
Figure 5-12.3. Brake master cylinder and brake power
booster, installed view.
Fluid salvaged from the system
during the bleeding operation is
aerated and is no longer suitable for
use in this system.
b. Installation. Reverse procedures in a above.
Bleed the brake hydraulic system as instructed in c
below.
16
TM 10-3930-618-34
C2
Page 5-24. Paragraph 5-20a(3). Change "(TM 10-3930618-20)" to read "(para 5-12.1)".
Page A-1. Paragraph A-2 is superseded as follows:
A-6. NonAeronautical Equipment
A-2. Painting
TM 43-0139 Painting Instructions for Field Use FM 520
Camouflage
A-7. Tires
TM 9-2610-200-20
TB 43-0210
Page A-1. Paragraph A-3. Line 3. Change ’"TM 103920-618-34P" to read ’"TM 10-3930-61834P".
Page A-1. Paragraph A-3, TM 38750 to read DA PAM
738-750.
Page A-1. Paragraph A-4. Change "TB 740-93-2" to
read "TB 740-97-2".
Page A-1. After Paragraph A-5, before Index page add
the following:
Page I-1, Index page, is superseded as follows:
Army Oil Analysis Program
Organizational Care, Main
tenance and Repair of
Pneumatic Tires and Inner
Tubes.
A-8. Decontamination
FM 2140
Chemical, Biological,
Radiological, and Nuclear
Defense (NBC)
A-9. Military Publication Indexes
DA PAM 310-1
Index of Military
Publications
INDEX
Paragraph
Page
Paragraph
G
Governor ..............................................
3-9
H
A
Alternator ............................................
B
3-2
3-1
Brake Master Cylinder ........................
Brake pedal ........................................
Bake Pedal and Linkage ....................
C
5-12.3
5-16
5-12.1
5-16
5-21
5-16
Camshaft, bearings and valve lifters ..
Carburetor ...........................................
Carriage and backrest ........................
Column ...............................................
Crankshaft, main bearings, gears
and pulley ...........................................
Cylinder head, block, and sleeves ......
D
3-24
3-8
4-7
5-4
3-50
3-8
4-10
5-5
3-21
3-20
3-42
3-36
Description................................... 1-4,3-5,5-1 1-1,3-7,5-1
Drive axle assembly ............................ 2-9,5-18 2-6,5-22
Drive axle housing and differential .....
5-20
5-24
E
Engine removal and disassembly .......
F
3-19
Flywheel, ring gear and housing..........
Forms and records .............................
Fuel tank .............................................
3-26
1-2
3-10
Page
3-12
Hand Brake Lever, Cables and Linkage 5-12.1
Handbrake assembly ..........................
5-12
Horn button and steering wheel ..........
5-3
Hydraulic control valve ........................
4-3
Hydraulic control valve and levers........
2-13
Hydraulic lift assembly ........................
2-11
Hydraulic lift cylinder ............................
4-6
Hydraulic lift mast.................................
4-7
Hydraulic pump assembly ...................
2-10
Hydraulic reservoir ..............................
4-4
I
5-16
5-16
5-5
4-3
2-12
2-10
4-8
4-10
2-9
4-6
Ignition coil ...................................
Inching pedal and brake pedal.............
M
3-4
3-17
3-7
3-34
Maintenance repair parts .....................
Maintenance requirements .................
Master cylinder ....................................
O
2-3
2-7
5-14
2-1
2-5
5-19
Oil pan..................................................
Oil pressure relief valve .......................
Oil pump ..............................................
P
3-12
3-14
3-13
3-15
3-19
3-16
Pistons and connecting rods ...............
3-22
3-43
3-36
3-53
1-1
3-14
17
TM 10-3930-618-34
C2
INDEX - CONTINUED
Paragraph
Page
Paragraph
Page
T
Planetary gears, axle shaft, wheel hubs
Power booster .....................................
Power plant..........................................
Power steering cylinder .......................
Pump assembly ...................................
R
5-19
5-17
2-3
5-7
4-2
5-23
5-21
2-1
5-10
4-1
Radiator ..............................................
Reporting of errors .............................
S
3-6
1-3
3-7
1-1
Scope .................................................
Shifting mechanism .............................
Special tools and equipment ..............
Starter motor .......................................
Steering axle and wheels ....................
Steering axle assembly ......................
Steering axle and tie rods ...................
Steering gear ......................................
Steering unit .......................................
1-1
5-6
2-2
3-3
5-8
2-14
5-10
5-2
5-5
1-1
5-8
2-1
3-5
5-12
2-13
5-13
5-1
5-5
Tie Rods .............................................. 5-10.1
Timing gears and cover ......................
3-25
Tools and equipment ..........................
2-1
Torque converter and pump ................
3-15
Transmission assembly .......................
3-16
troubleshooting ....................................
2-5
5-15
3-52
2-1
3-20
3-24
2-1
U
Universal joint....................................
5-21
5-26
3-23
3-46
5-13
5-15
5-17
5-21
V
Valves and rocker arm assembly.........
W
Wheel brake assembly.........................
Wheel cylinder .....................................
By Order of the Secretary of the Army:
JOHN A. WICKHAM, JR.
General United States Army
Chief of Staff
Official:
ROBERT M. JOYCE
Major General, United States Army
The Adjutant General
Distribution:
To be distributed in accordance with DA Form 12-25A direct and general support maintenance requirements for
Warehouse Equipment.
18
TM 10-3930-618-34
TECHNICAL MANUAL
No. 10-3930-618-34
}
HEADQUARTERS
DEPARTMENT OF THE ARMY
WASHINGTON, D. C., 12 May 1971
DIRECT SUPPORT AND GENERAL SUPPORT
MAINTENANCE MANUAL
TRUCK, LIFT, FORK; GASOLINE ENGINE DRIVEN;
PNEUMATIC - TIRED WHEELS;
6000 LB CAPACITY; 168 INCH LIFT; ALLIS-CHALMERS
MODEL FP60-24PS;
ARMY MODEL MHE213 FSN 3930-93S-7979
___________
Paragraph
Page
CHAPTER
Section
1.
I.
II.
General..................................................................................................... 1-1 1-3
Description and data ................................................................................. 1-4 1-5
INTRODUCTION
CHAPTER
2.
Section
I.
II.
III.
IV.
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
INSTRUCTIONS
Repair parts, special tools and equipment ............................................... 2-1 2-3
Troubleshooting........................................................................................ 2-4 2-5
General maintenance .............................................................................. 2-6 2-7
Removal and installation of major components and auxiliaries ............. 2-8 2-15
2-1
2-1 2-5
2-5
2-5 2-17
CHAPTER
Section
3.
I.
II.
III.
IV.
V.
VI.
VII.
REPAIR OF POWER PLANT
Repair of engine electrical system............................................................ 3-1 3-4
Repair of cooling system .......................................................................... 3-5 3-6
Repair of engine fuel system ................................................................. 3-7 3-10
Repair of engine lubrication system .................................................... 3-11 3-14
Repair of torque converter and pump............................................................ 3-15
Repair of transmission.......................................................................... 3-16 3-17
Repair of engine .................................................................................. 3-18 3-26
3-1 3-7
3-7 3-8
3-7 3-14
3-15 3-20
3-20 3-24
3-24 3-36
3-36 3-54
CHAPTER
Section
4.
I.
II.
III.
REPAIR OF HYDRAULIC SYSTEM
Hydraulic system .................................................................................... 4-1 4-4
Repair of hydraulic lift cylinder ................................................................. 4-5 4-6
Repair of lift mast...................................................................................... 4-7 4-8
4-1 4-6
4-6 4-9
4-10 4-13
CHAPTER
Section
5.
I.
II.
III.
IV.
REPAIR OF FRONT AND REAR AXLE ASSEMBLIES
Repair of steering system ..................................................................... 5-1 5-10
Repair of brake system........................................................................ 5-11 5-17
Repair of drive axle.............................................................................. 5-18 5-20
Repair of universal joint ................................................................................. 5-21
5-1
5-16
5-22
5-26
APPENDIX
A.
REFERENCES
INDEX
i
1-1
1-1 1-2
5-16
5-22
5-26
5-27
Number
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
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
3-18
3-19
3-20
3-21
3-22
3-23
3-24
3-24
3-25
3-26
3-27
3-28
3-28
3-29
3-30
3-31
3-32
3-33
3-34
3-35
3-36
3-37
3-38
3-39
3-40
3-41
4-1
4-2
4-3
4-4
4-5
4-6
4-7
5-1
5-1
5-2
5-3
5-4
5-5
5-6
5-7
LIST OF ILLUSTRATIONS
Title
Transmission assembly removal and installation.............................................................................................
Torque converter removal and installation ......................................................................................................
Converter installation ..................................................................................................... ................................
Hydraulic pump removal and installation ........................................................................................................
Hydraulic lift assembly removal and installation ..............................................................................................
Tilt cylinder removal and installation................................................................................................................
Hydraulic control valve removal and installation .............................................................................................
Steering axle assembly removal and installation.............................................................................................
Drive axle assembly removal and installation..................................................................................................
Alternator, exploded view................................................................................................................................
Checking rotor and stator for shorts, grounds and open circuits .....................................................................
Checking heat sink diodes .................................................................................................. ...........................
Brush holder assembly....................................................................................................................................
Checking alternator output ..............................................................................................................................
Starter motor disassembly and assembly........................................................................................................
Carburetor disassembly ..................................................................................................................................
Governor disassembly.....................................................................................................................................
Fuel tank .........................................................................................................................................................
Oil pan, removal 2nd installation .....................................................................................................................
Oil pump..........................................................................................................................................................
Checking oil pump radial clearance ................................................................................................................
Positioning drive gear offset slot ....................................................................................................................
Oil pressure relief valve..................................................................................................................................
Checking pump and converter pressure .........................................................................................................
Checking clutch pressure................................................................................................................................
Transistor, removal and installation ................................................................................................................
Pump removal and installation ........................................................................................................................
Torque converter and pump assembly, disassembly and reassembly ............................................................
Transmission...................................................................................................................................................
Housing and drum assembly removal and installation ....................................................................................
Forward and reverse disc assembly ...............................................................................................................
Transmission control valve................................................................................................. .............................
Single speed transmission, disassembly (sheet 1 of 2)........... ........................................................................
Single speed transmission, disassembly (sheet 2 of 2) ..................................................................................
Reverse gear and shaft, removal and installation............................................................................................
Idler gear shaft, removal and installation.........................................................................................................
Output gear and shaft removal and installation ..............................................................................................
Brake pedal (sheet 1 of 2) ................................................................................................ ..............................
Brake pedal (sheet 2 of 2) ..............................................................................................................................
inching pedal ..................................................................................................................................................
Cylinder head and valves ...............................................................................................................................
Sequence for cylinder head capscrew tightening ...........................................................................................
Cylinder block ............................................................................................................ ....................................
Crankshaft- gear and pulley. ...........................................................................................................................
Removing crankshaft .....................................................................................................................................
Piston and connecting rod...............................................................................................................................
Intake and exhaust valve assembly.................................................................................................................
Valve operating mechanism and camshaft .....................................................................................................
Crankshaft hearing installation .......................................................................................................................
Checking camshaft thrust clearance ..............................................................................................................
Timing gear cover and rear support ...............................................................................................................
Flywheel, ring gear, and housing ....................................................................................................................
Hydraulic pump disassembly and reassemble.................................................................................................
Hydraulic control valve ...................................................................................................................................
Hydraulic reservoir ..........................................................................................................................................
Tilt cylinder.................................................. ....................................................................................................
Hydraulic lift cylinder ......................................................................................................................................
Hydraulic lift mast............................................................................................................................................
Hydraulic lift carriage and backrest .................................................................................................................
Steering gear assembly removal and installation (sheet 1 of 2) ......................................................................
Steering gear assembly removal and installation (sheet 2 of 2).......................................................................
Steering gear assembly ..................................................................................................................................
Checking control spool rotation ......................................................................................................................
Removing check valve seal plug .....................................................................................................................
Installing entering spring set............................................................................................................................
Drive gear alinement .......................................................................................................................................
Forward reverse lever assembly .....................................................................................................................
ii
Page
2-7
2-8
2-8
2-10
2-11
2-12
2-13
2-14
2-16
3-1
3-2
3-3
3-4
3-5
3-6
3-11
3-13
3-14
3-16
3-17
3-18
3-19
3-20
3-21
3-21
3-22
3-23
3-23
3-25
3-25
3-28
3-29
3-30
3-31
3-32
3-32
3-32
3-35
3-35
3-36
3-38
3-39
3-41
3-43
3-43
3-44
3-47
3-48
3-52
3-52
3-53
3-54
4-3
4-5
4-6
4-8
4-9
4-11
4-13
5-2
5-3
5-4
5-5
5-6
5-7
5-8
5-9
LIST OF ILLUSTRATIONS - Continued
Number
5-8
5-9
5-10
5-11
5-12
5-13
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
Title
Page
Power steering cylinder with yoke ..................................................................................................................
Steer wheel and bearings. removal and installation.........................................................................................
Steering axle and tie rods..................................................................................... ...........................................
Stop adjustment ..................................................................................................... .........................................
Hand brake assembly......................................................................................................................................
Wheel brake assembly (sheet 1 of 2) .............................................................................................................
Wheel brake assembly (sheet 2 of 2) .............................................................................................................
Brake master cylinder, installed view ..............................................................................................................
Master cylinder................................................................................................................................................
Brake power booster, installed view ...............................................................................................................
Brake power booster components ..................................................................................................................
Drive axle assembly .......................................................................................................................................
Drive axle housing and differential ..................................................................................................................
Universal joints................................................................................................................................................
iii
5-11
5-13
5-14
5-16
5-17
5-18
5-19
5-19
5-20
5-21
5-22
5-24
5-25
5-27
CHAPTER I
INTRODUCTION
Section I. GENERAL
used by maintenance personnel at all maintenance
levels are listed in, and prescribed by, TM 38-750.
1-3. Reporting of Errors
Report of errors, omissions, and recommendations for
improving this publication by the individual user is
encouraged. Reports should be submitted on DA Form
2028, (Recommended Changes to Publications) and
forwarded direct to Commanding General, U.S. Army
Mobility Equipment Command, ATTN: AMSME-MPP,
4300 Goodfellow Boulevard, St. Louis, Mo. 63120.
1-1. Scope
This manual contains instructions for the use of direct
support and general support maintenance personnel
maintaining the fork lift truck (Allis-Chalmers Model
FP60-24PS) as allocated by the Maintenance Allocation
Chart.
It provides information on equipment
maintenance which is beyond the scope of the tools,
equipment, personnel, or supplies normally available
at organizational maintenance.
1-2. Forms and Records
Maintenance forms, records and reports which are to be
Section II. DESCRIPTION AND DATA
Fuel feed ............................. Mechanical pump is a camshaft operated valve and
diaphragm type
Air cleaner ........................... Oil bath type
Ignition................................. Battery and distributor.
distributor gap 0.022 in.
Oil pump:
Type .................................... Gear
Pressure.............................. 70-90 psi (pound per square
inch) relief valve bypass
Valves ................................ Rotator type
Valve clearance:
Intake (cold) ..................... 0.012 in.
Exhaust (cold) ................. 0.014 in.
Intake (hot) ...................... 0.010 in.
Exhaust (hot) .................. 0.012 in.
Hydraulic Pump Specifications:
Primary flow ..................... 2 to 3 GPM (gallons per
minute)
Secondary flow.................... 18 to 19 GPM
RPM (Revolutions per
minute) ............................. 2200
PSI (Pounds per
square inch).................. 2000
Primary flow relief:
Valve set at ..................... 1600 ±100 PSI
(2) Torque converter and transmission.
Manufacturer ............ Allis-Chalmers
(3) Clutch assembly.
Manufacturer ...................... Allis-Chalmers
(4) Generator.
Manufacturer ....................... Delco-Remy
(5) Starter motor.
Manufacturer ....................... Delco-Remy
(6) Distributor.
Manufacturer ....................... Delco-Remy
(7) Fuel pump.
Manufacturer .................... AC Spark Plug Div of General
Motors Corp
1-4. Description
A general description of the fork lift truck is contained in
TM 10-3930-618-10. A more detailed description of
specific components and assemblies is contained in the
applicable sections of this manual. Detailed description
of components and assemblies are provided in the
applicable maintenance paragraphs of this manual.
1-5. Tabulated Data
a. Identification. The major identification plates of the
fork lift truck are located and described in TM 10-3930618-20.
b. Tabulated Data.
(1) Engine assembly.
Manufacturer .....................Allis-Chalmers
Model..................................6MB230
Type....................................OHV (overhead valve)
Number of cylinders ...........6
Piston stroke.......................4 1 / 8 inches
Bore ....................................3 7/16 inches
Compression ......................7.3:1
Piston displacement ...........230 cubic inches
Firing order .........................1-5-3-6-2-4
Governed speed .................2200 rpm (revolutions per
minute) under load
Idle speed ...........................500 rpm
S.A.E. rated horsepower (HP)
Maximum @ 2200 rpm..... 55.0 hp
Intermittent @ 2200 rpm .. 49.5 hp
Continuous @ 1800 rpm .. 36 hp
Lubrication ..........................Forced feed main and connecting rod bearings with oil
filter
Cooling system ...................Pressure-type radiator, with
fan and water pump
Electrical system.................12 V dc (volts, direct current)
1-1
(8) Torque valves. See table 1-1 for special
torque values for stated applications See table 1-2 for
general torque values, to be used on nuts and bolts
where specific valves are not stated.
Table 1-1. Special Torque Values
Application
Engine cylinder mounting
Cylinder head lifting
Thermostat housing and cylinder head
Water outlet
Manifold, intake and exhaust
Main bearing mounting
Connecting rod
Crankshaft pulley retaining
Pressure regulating screw
Lube oil filter mounting
Spark plugs
Ft-Lb.
Torque
110-120
110-120
110-120
18-21
32-35
120-130
45-50
240-260
125-135
45-50
25-30
Thread
Size
1/2-13
1/2-20
1/2-13
3/8-16
7/ 16-20
9/16-12
3/8-24
1-16
3/4-16
1/2-13
14MM
Table 1-2. General Torque Values (Foot-pounds torque)
Capscrew
Size
1/4
5/ 16
3/8
7/ 16
1/2
9/ 16
5/8
3/4
7/8
1
Grade 2
NC
NF
5-7
6-8
11-13
13-15
18-21
19-22
30-33
32-35
45-50
45-50
60-65
60-65
75-85
75-85
105-115
105-115
105-115
105-115
140-150
450-475
Grade 5
NC
NF
9-11
11-13
18-20
21-23
28-33
30-35
44-49
50-55
68-73
68-73
95-105
95-105
125-135
125-135
210-230
210-230
290-310
290-310
380410
1-2
Grade 8
NC
NF
12-14
14-16
25-27
28-30
50-55
69-74
69-74
72-77
95-105
95-105
130-140
130-140
170-190
170-190
290-310
290-310
450-500
450-500
CHAPTER 2
DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE
INSTRUCTIONS
Section I. REPAIR PARTS, SPECIAL TOOLS AND EQUIPMENT
direct and general support maintenance of the fork lift
truck.
2-3. Maintenance Repair Parts
Repair parts required to perform direct and general
support maintenance is listed and illustrated in TM 103930-618-34P.
2-1. Tools and Equipment
Tools, equipment, and repair parts issued with or
authorized for the fork lift truck are listed in TM 10-3930618-20.
2-2. Special Tools and Equipment
No special tools or equipment are required to perform
Section II. TROUBLESHOOTING
Each malfunction stated is followed by a list of probable
causes of the trouble.
The corrective action
recommended is described opposite the probable cause.
Refer to TM 10-3930-618-20 for initial troubleshooting
information.
2-4. General
This section provides information useful in diagnosing
and correcting unsatisfactory operation or failure of the
fork lift and its components.
2-5. Troubleshooting
Malfunctions which may occur are listed in table 2-1.
Table 2-1. Troubleshooting
Malfunction
Probable cause
1. Engine hard to start
No compression
2. Engine misses
a. Leaks at cylinder head gaskets
b. Engine overheats, causing valves
to stick
c. Warped valves
d. Stuck valve
3. Engine knocks
4. Engine overheats
a. Carbon in combustion chamber
("piping" knock in cylinder)
b. Loose connecting rod bearing,
(Sharp knock, low oil pressure.)
c. Loose main bearing. (Heavy
knock-low oil pressure.
d. Loose piston pins (Sharp double
knock 3-22).
e. Piston and cylinder wear
Leaky radiator.
2-1
Corrective action
Valves not seating properly. Either
adjust (TM 10-3930-618-20) or
grind valves (para 3-23).
a. Tighten head or replace gasket
(para 3-20).
b. Free the valves by cleaning the
valve stems (para 3-23).
c. Replace (para 3-23).
d. Remove valve cover and with
screwdriver, free the sticking
valve. Valve stem and guide will
have to be cleaned to restore
proper clearance. If condition
continues, valves need regrinding
(paras 3-23).
a. Remove cylinder head; scrape and
clean out carbon (para 3-20).
b. Replace bearings (para 3-22).
c. Replace main bearings (para 3-21)
d. Replace pins, or bushings (para
e. Replace sleeve (para 3-20), piston
and rings (para 3-22).
Repair. Do not use quick-stop lead
solders, as these tend to clog the
circulation. Lead solder must be
used (para 3-6).
Table 2-1. Troubleshooting (Continued)
Malfunction
5. Loss of power
Probable cause
a. Lower oil pressure, due to (1)
external oil leaks, (2) thin oil or
(3) sticking of oil pressure relief
valve.
b. Leaky valves.
c. Worn piston rings
d. Blown cylinder head gasket
6. Explosion in exhaust
Partially open exhaust valve.
7. Engine runs irregularly (sputters)
a. Warped exhaust valve.
b. Leaky valves.
c. Loose jets in the carburetor.
8. Smoky exhaust
a. Carburetor float sticking (black
smoke)
b. Worn piston rings, and out-ofround and tapered cylinders
(blue smoke)
c. Thin lubrication oil (blue smoke)
9. Ammeter does not register
10. Alternator does not generate
current
11. Starting motor failure
Slip-rings dirty.
a. Shorted rotor.
b. Shorted stator.
a. Faulty switches.
b. Commutator dirty.
12. No gasoline at the carburetor
13. Carburetor leaks gasoline when
idling.
14. Radiator boils.
c. Worn brushes.
d. Bad teeth on flywheel.
Float stuck (dirty needle valve).
a. Float stuck (dirty needle valve)
b. Float level incorrect
c. Drain plug not tight.
a. Frozen radiator.
b. Leaky radiator.
15. Unable to lift or tilt load.
a.
b.
c.
d.
Air leak at suction line.
Damaged or worn pump.
Relief valve binding open
Damaged lift cylinder.
2-2
Corrective action
a. (1) Repair leaks by lightening the
connections, or replacing the
line; (2) Drain and fill with fresh
oil; (3) Remove oil pressure relief
valve and clean (para 3-14). Do
not stretch spring.
b. If the leaky valve is caused by its
improper adjustment, adjust or
grind valve (para 3-23).
c. Replace rings (Para 3-22).
d. Replace cylinder head gasket
(para 3-20).
Remove gum from valve stem. or
adjust tappet clearance or replace
broken spring (para 3-23).
a. Replace valve (para 3-23).
b. Adjust tappet clearance regrind.
or replace (para 3-23).
c. Remove carburetor and tighten
(para 3-8).
a. Tap carburetor lightly with
hammer handle. If this does not
correct the situation carburetor
must be cleaned (para 3-8).
b. Replace rings (para 3-22) and
cylinder sleeves (para 3-20).
c. Use oil correct viscosity (LO 103930-618-12).
Clean slip-rings (para 3-2).
a. Replace or repair (para 3-2).
b. Replace or repair (para 3-2).
a. Check ignition switch or magnetic
starting switch.
b. Clean with No. 00 sandpaper; do
not use emery cloth (para 3-3).
c. Replace (para 3-3).
d. Replace ring gear (para 3-26).
Tap the carburetor bowl gently. or
remove the carburetor, and (lean
the needle valve and float
chamber (para 3-8).
a. Tap carburetor gently to dislodge
dirt in fuel valve, or remove
carburetor and clean valve (para
3-8).
b. Adjust (para 3-8).
c. Tighten (para 3-8).
a. Run engine for 3 minutes with
blanket covering radiator. Stop
for 5 minutes. Run for 3 minutes
and stop for 5 minutes. Continue
this operation until radiator is
thawed. Check for leaks.
CAUTION: Do not run continuously)
to thaw. Water will boil away and
overheat seriously damaging
engine.
b. Repair radiator. Do not use liquid
solder, as it tends to clog the
system (para 3-6).
a. Tighten connections.
b. Remove and repair (para 4-2).
c. Remove and repair (para 4-3).
d. Check for binding or any cause to
make plunger inoperative(para 4-6)
Table 2-1. Troubleshooting (Continued)
Malfunction
Probable cause
e. Control valve inoperative.
16. Lift and till too slow.
a. Internal leakage at pump.
b. Excessive leakage at cylinder
packing.
c. Air leaks in system.
d. Misalignment.
e. Faulty relief valve.
17. Load creeps when tilting or
a. Internal leakage in cylinders.
lowering.
b. Oil leak at packing glands.
c. Leak in control valve.
18. Noisy hydraulic pump.
d. Leaks in oil lines.
damaged lines.
a. Insufficient or no oil.
b. Air leaks.
c. Oil bubbles in intake oil.
19. Oil overheating.
20. Failure to operate.
d. Coupling misalignment
e. Pump mounting flange I loose
f. Worn or broken parts.
a. Internal oil leakage.
b.
c.
a.
b.
c.
d.
e.
f.
g.
21. Truck moves in one direction but
not in other.
22. Axle noise drive or coast.
23. Continuous axle noise.
a.
Pump too tight after overhaul.
Restricted lines.
Broken axle shaft.
Teeth broken on axle shaft
planetary gears.
Broken teeth on ring gear or
pinion.
Worn disc in transmission
Worn transmission oil
Stripped gears and worn bearings
in transmission.
Valve plunger stuck in transmission control valve.
Worn disc in transmission.
b. Binding valve plunger in transmission control valve.
a. Excessive wear at ring gear and
pinion.
b. Worn pinion gears or side gears in
differential case.
a. Excessive wear in gear train.
b. Lack of lubrication.
24. Excessive backlash in unit.
25. Pedal goes to toe board.
26. Both brakes drag.
c. Worn or damaged drive wheel
bearing.
a. Worn splines on axle shafts.
b. Worn ring gear, pinion or differential case pinions.
c. Loose or worn universal joints.
External leak in brake system or leak
past master cylinder piston cup.
a. Mineral oil in brake system.
2-3
Corrective action
e. Inspect for internal leakage or
damaged parts, and repair (para
4-3).
a. Inspect for worn or damaged
parts (para 4-2).
b. Repair or replace packing (para
4-8 & 4-6).
c. Tighten all connections.
d. Check mast (para 4-8) or tilt
linkage (TM 10-3930-618-20)
for cause of binding.
e. Check for worn or damaged parts.
Repair or replace (para 4-3).
a. Repair or replace packing (para 4-5)
and para 4-6).
b. Repair or replace packing (para
4-5 and 4-6).
c. Check for worn or damaged
plungers (para 4-3).
d. Tighten all connections or replace
a. Check tank for proper oil level or
restricted suction line (para 4-4).
b. Tighten intake connections.
c. Use hydraulic oil with antifoaming
characteristics. (LO 10-3930618-12).
d. Realign.
e. Tighten (para 4-2).
f. Replace (para 4-2).
a. Repair or replace pump (para
4-2).
b. Remove and repair (para 4-2).
c. Check and repair.
a. Replace axle (para 5-19).
b. Replace axle shaft or planetary
gears. (para 5-19).
c. Replace ring gear and pinion (para
5-20).
d. Replace disc (para 3-16).
e. Replace pump (para 3-15).
f. Replace worn parts (para 3-16).
g. Disassemble valve clean, and
replace worn parts (para 3-16).
a. Replace disc (para 3-16).
b. Disassemble valve clean, and
replace worn parts (para 3-16).
a. Replace (para 5-20).
b. Replace worn gears (para 5-21).
a. Replace worn part (para 5-19
and 5-20).
b. Lubricate according to LO 103930-618-12.
c. Replace bearings (para 5-20).
a. Replace axle shafts (para 5-19).
b. Replace gear and pinions (para
5-20).
c. Tighten or replace (para 5-21).
Check master cylinder for leak and
repair (par 5-14).
a. Clean out system, replace cups in
brake cylinders and refill with
Table 2-1. Troubleshooting (Continued)
Malfunction
27. One wheel drags.
28. Truck pulls to one side.
Probable cause
b. Breather port in master cylinder
clogged.
a. Weak or broken brakeshoe return
springs.
b. Loose wheel bearings.
c. Swollen wheel cylinder piston cups
or piston binding.
a. Grease or brake fluid on brake
lining.
b. Loose wheel bearings.
c. Different brakes of brake lining.
used at each wheel.
d. Lining charred or drum scored.
29. Spongy brakes.
30. Excessive pedal pressure
Shoe surface not square with drum.
a. Incorrect brake lining.
31. Light pedal pressure-brakes too
severe.
b. Oil or fluid soaked lining.
a. Small amount of grease or brake
fluid on lining.
b. Incorrect lining.
32. Brakes squeak.
33. Loss of coolant.
34. Rapid wear or breakage of fan
belt.
35. Ammeter does not show charge.
36. Ammeter shows discharge during
engine operation.
37. Ammeter show heavy discharge
with engine stopped.
38. Ammeter shows rapid fluctuation.
39. Starting motor failure.
40. Hard steering.
41. Steering too sensitive.
c. Defective power booster.
a. Brake shoes twisted.
b. Particles of metal or dust imbedded in lining.
a. Cracked engine block or head.
b. Defective head gasket.
c. Leaky radiator.
Excessive drag from alternator.
a. Worn alternator brushes.
b. Shorted alternator armature.
c. Shorted alternator fields.
Inoperative alternator.
Defective alternator regulator.
a. Dirty, loose or worn alternator
brushes.
b. Defective alternator.
a. Commutator dirty.
b. Worn brushes.
c. Broken drive mechanism.
d. Bad teeth on flywheel.
a. Failure of hydraulic pump.
b. Badly worn pump.
c. Broken or weak relief valve spring.
d. Binding relief valve.
e. Low pump pressure.
f. Line leakage.
g. Leakage in steering cylinder.
h. Faulty regulator valve.
i. Binding steering gear.
a. Pump pressure too high.
b. Faulty flow control valve.
42. Loose steering.
Loose kingpins.
2-4
Corrective action
brake fluid TM 10-3930-618-20.
b. Clean out breather port (para
5-14).
a. Replace broken or weak springs
para 5-13).
b. Readjust (TM 10-3930-618-20).
c. Replace defective or damaged
parts (para .5-15).
a. Replace with new lining (para
5-13).
b. Readjust (TM 10-3930-618-20).
c. Make sure same type ,of lining is
d. Replace lining (para 5-13) or
repair or place drum (para
5-13).
Repair (para 5-13).
a. Install specified lining (para
5-13).
b. Replace lining (para 5-13).
a. Correct cause and replace lining
(para 5-13).
b. Install specified lining (para
5-13).
c. Replace or repair (para 5-13).
a. Replace(para 5-13).
b. Remove foreign material, and
sand lining and drum (para
5-13).
a. Replace damaged part (para
3-20)
b. Replace (para 3-20).
c. Repair or replace (para 3-6).
Check alternator bearings (para 3-2).
a. Replace brushes (para 3-2).
b. Test alternator (para 3-2).
c. Test alternator (para 3-2).
Test alternator (para 3-2)
determine cause.
Inspect for closed contacts. Adjust or
replace regulator (TM 10-3930618-20).
a. Clean and tighten brushes.
Replace if worn (para 3-2).
b. Repair or replace (para 3-2).
a. Clean (para 3-3).
b. Replace (para 3-3).
c. Replace (para 3-3).
d. Replace ring gear {para 3-26).
a. Replace or recondition (para 4-2).
b. Recondition pump (para 4-2).
c. Replace spring (para 4-2).
d. Free up valve (para 4-2).
e. Replace worn or faulty parts (para
4-2).
f. Tighten connections.
g. Repair (para 5-7).
h. Recondition valve (para 4-2).
i. Repair (or adjust (para 5-7).
a. Check for binding relief valve
(para 4-2).
b. Recondition-free tip any binding
parts (para 4-2).
Repair or recondition (para 5-10).
Table 2-1. Troubleshooting (Continued)
Malfunction
43. Low, oil pressure.
Probable cause
Corrective action
d. Low oil level.
b. ’Worn hydraulic pump.
c. Weak relief valve spring.
d. Relief valve stuck open.
e. Flow control valve stuck open.
f. External leakage.
g. Internal leakage.
a. Fill reservoir to correct level (LO
10-3930-618-12).
b. Recondition or replace (para 4-2).
c. Replace spring (para 4-2).
d. Remove and free up valve (para
4-2).
e. Free up flow control valve (para
4-2).
f. Tighten or replace fittings hoses, or
seals (para 4-2).
g. Replace seals in pump (para 4-2)
or cylinder (para 4-2).
Section III. GENERAL MAINTENANCE
be sure the chamfered side faces the shoulder.
Lubricate the bearing and its mating surface when
pressing a bearing into place. Press bearings only on
the race adjacent to the mating part. Use drivers which
contact as much of the race as possible.
2-6. General
This section contains general maintenance information
that would otherwise have to be repeated throughout this
manual.
2-7. Maintenance Requirements
a. Hardware and Threaded Parts.
Inspect
hardware for damaged threads, rounded corners, and
damaged slots. Threaded holes and parts should accept
their mating parts without requiring excessive torque.
Threads may be chased with a tap or die. Replace any
threaded parts which cannot be repaired.
b. Gaskets.
Replace all gaskets .which are
disturbed during repair operation or which show evidence
of leakage. When installing gaskets, insure all gasket
surfaces are clean and free from nicks and burs. Use
grease or gasket cement to retain gasket in position
during assembly procedure.
c. Oil Seals and Packings. Thoroughly lubricate
the sealing lip of spring loaded seals with grease or other
suitable lubricant when installing. Apply nonhardening
sealer to the outer circumference of encased seals or to
the mating bores to prevent possible leakage. Immerse
preformed packings in the liquid or lubricant with which
they will be in contact.
d. Ball and Roller Bearings.
After removing
antifriction bearings, cover them immediately to keep out
dirt and abrasives. Flush thoroughly with solvent, tap
them against a wooden block to remove packed
lubricant, and air-dry. Coat cleaned bearings with oil
and wrap in clean paper. Replace any bearings that are
scored, pitted, discolored from overheating, or otherwise
damaged. When installing bearings against shoulders,
e. Repair of Damaged Machined and Polished
Surfaces. Remove rough spots, scores, burs, galling,
gouges, and other surface damage from machined and
polished surfaces. Use a suitable honing stone, crocus
or emery cloth, file, or any other method that will permit
the part to function efficiently. The finish of the part must
approximate that of the original finish. Do not alter
critical dimensions beyond acceptable limits. Build up
shafts, rods, and other worn parts by metallizing,
chrome plating, or welding. Grind built up parts to
original size.
f. Welding Repair. Welding must be performed by
a qualified welder. Welds must provide complete fusion
and
penetration
and
comply
with
governing
specifications. Inspect all welds using a radiographic or
magnetic particle process. Grind all new welds flat and
smooth whenever possible.
g. Part Replacement. Replace parts which are
worn or defective with new parts. Consider such factors
as age, mileage, operating hours, usage, and part
availability to determine the necessity of part
replacement.
Section IV. REMOVAL AND INSTALLATION OF MAJOR
COMPONENTS AND AUXILIARIES
assembly (mast, carriage, and cylinders); steering axle;
and hydraulic system. This section covers direct and
general support maintenance instructions for the
removal,
2-8. General
The major components of the fork lift truck are; the
power plant (engine, torque converter, and transmission;
drive axle (differential, brakes and wheels); hydraulic lift
2-5
installation, and where necessary the adjustment of
these components as authorized by the maintenance
allocation chart (TM 10-3930-618-20).
(12) Attach a suitable lifting sling and hoist to
the two lifting studs provided on engine head.
(13) Raise engine, high enough to clear engine
supports. Move engine toward rear to free transmission
from drive shaft slip joint. Then raise and remove engine
from truck.
2-9. Power Plant
a. Removal.
(1) Refer to TM 10-3930-618-20 and perform
the following:
(a) Remove the overhead guard.
(b) Remove the operators seat and
engine hood.
(c) Remove toe plate and floor plate.
(2) Remove counterweight (TM 10-3930-61820).
(3) Drain engine cooling system and remove
radiator and hose connections. (TM 10-3930-618-20).
(4) Disconnect hydraulic noses at pump and
remove hose clamps on each side of oil pan holding
hoses in position. Lines, should then be tied out of the
way.
(5) Disconnect wiring harness terminals from
engine, being careful not to damage leads.
For
convenience in reinstallation, tag all terminals showing
where wires should be installed.
(6) Disconnect fuel lines (TM 10-3930-61820).
(7) Disconnect all throttle (TM 10-3930-61820) and shift linkage (para 5-6).
(8) Disconnect exhaust pipe from manifold
(TM 10-3930-618-20).
(9) Disconnect carburetor air inlet hose from
carburetor.
(10) Disconnect the propeller shaft (para 5-21).
(11) Remove nuts, washers, and capscrews
securing front and rear engine mounts to truck frame.
CAUTION
Use care when removing engine;
make certain that no parts are
damaged by careless handling.
(14) After engine assemble with transmission
has been removed from truck, it is recommended that all
accessories be removed for ease of engine disassembly.
Enough pans or boxes should be available so that
components removes from the engine can be placed in
them and kept separated, making reinstallation easier
and quicker. For specific instructions on removal and
installation of accessories, refer to the appropriate
sections of T.M 10-3930-618-20, and of this manual.
b. Separating Engine From Converter and
Transmission.
(1) Attach sling and hoist to transmission case
and then take up slack until there is no weight on slings,
but slings are straight.
(2) Remove capscrews and lockwashers
securing the converter housing to the flywheel (fig. 2-1).
(3) Disconnect the cooler lines at bottom right
side of sump.
(4) Drain oil from transmission by removing
drain plug from sump.
(5) Carefully work transmission away from
engine and flywheel housing.
2-6
Figure 2-1. Transmission assembly removal and installation.
c. Separating
Flywheel.
Torque
Converter
From
the
Note how many shims are on the converter pilot (fig. 2-2
NOTE
When
torque
converter
and
transmission are separated, proceed
to paragraphs 3-15. for repairs. To
install replacement torque converter
and/or transmission, proceed as
follows:
(1) Refer figure 2-2 and remove 6 capscrews
and lockwashers that secure the torque converter to the
flywheel.
(2) Slide torque converter off the flywheel.
2-7
(b) Place scale across tangs of
converter and another scale front flyweel housing face to
the first scale (fig. 2-3).
A. SEPARATING CONVERTER
FROM FLYWHEEL
A. CHECKING CONVERTER TANG DEPTH
B. CONVERTER PILOT AND SHIM
ME 3930-618-34/2-2
B. Converter pilot and shim
1 Bolt
2 Plate. reinforcing
3 Plate, drive
4 Shim
5 Converter
Figure 2-2. Torque converter removal and installation.
d. Assembly of Power Plant.
(1) Torque converter installation.
(a) Without shims (fig. 2-2) on pilot,
install converter on flywheel. Tighten capscrews.
NOTE
When installing converter it is
important that tongs of converter
extend to a proper depth into pump.
B. CHECKING CONVERTER ALIGNMENT
ME 3930-618-34/2-3
Figure 2-3. Converter installation.
2-8
(c) Record measurement from face of
tangs to housing face.
(d) If measurement is less than 2 31/ 32
inches (2.968 inches) remove converter and add shims
at converter pilot to obtain specified dimension.
(e) If measurement is greater than 2 63
/ 64 inches (2.982 inches) insert a suitable gasket
between the converter housing and flywheel housing to
obtain the specified dimension.
(f) Mount a dial indicator, (fig. 2-3) on
the flywheel housing. Rotate converter and note dial
indicator readings. Hub runout should not exceed 0.005
inch (0.01 inch T.I.R) (Total Inches Runout).
(g) Bend converter plate to adjust to
specified dial reading. Do not use shims between plate
and flywheel.
(h) After correct alignment is obtained,
recheck tang depth as outlined above.
(2) Transmission Installation.
(a) Mark one mounting strap and
flywheel for identification and remove converter from
flywheel being careful not to damage or lose shims, if
any, on converter pilot.
(b) Position converter in pump at back
of transmission making sure converter hub tangs
properly engage pump driven gear.
(c) Reinstall transmission on flywheel
bell housing as follows:
1. Mount converter on flywheel by
installing capscrews and lockwashers trough timing mark
inspection plate in flywheel housing.
2. After converter has been securely
installed, rotate until filler hole appears and add 1 quart
of oil.
3. After assembly has been installed
in truck, add 10 quarts of oil to transmission.
e. Power Plant Installation. The installation of
engine assembly with transmission is practically a
reversal of the procedures in paragraph 2-9a.
(1)
Using an engine lifting sling attached on
the lifting studs on the cylinder head, and with a suitable
hoist, slowly lower engine into truck frame. Have an
assistant line up drive shaft slip joint so that it will enter
output shaft of transmission without damage during
installation.
(2) With engine correctly aligned in truck
frame and positioned on the rubber mounts, install the
mounting capscrews, washers, and nuts. Torque nuts to
60 foot-pounds and remove hoist and sling.
(3) Connect exhaust pipe, using a new
gasket.
(4) Connect throttle and shaft linkage, and
make initial adjustments to linkage at this time (TM 103930-618-20). Final adjustment can be made after
installation is complete.
(5) Connect fuel supply line and open shutoff
valve (TM 10-3930-618-20).
(6) Install wiring harness. If ends of leads
have not been tagged, refer to Electrical System section
(TM 10-3930-618-201.
(7) Clamp hydraulic hoses along oil pan and
connect hose to hydraulic pump.
(8)
Install radiator and hoses. Pour coolant
into engine cooling system and check for leaks. Refer to
Cooling System section, (TM 10-3930618-20).
(9) Install counterweight (TM 10-3930-61820).
2-10. Hydraulic Pump Assembly
a. Description. The hydraulic pump is a gear type
unit, driven directly through a flexible coupling from the
engine crankshaft. With this type of installation the
pump is always driven at engine speed.
b. Removal.
(1) Remove radiator grille (TM 10-393061820).
(2) Refer to figure 2-4 and disconnect the
hydraulic pump from the engine drive coupling.
NOTE
It is not necessary to drain hydraulic
reservoir since oil level is below that
of pump fittings.
(3) Remove capscrews (3), and lockwashers
(2), attaching flange to the timing gear cover.
(4) Remove the pump and flange by pulling
straight away from engine.
(5) Remove capscrews (4), lockwashers (5),
and coupling (1), from crankshaft pulley.
c. Installation.
(1) Install the hydraulic pump on the engine by
reversing the procedure in b above.
(2) Pump shaft splines should slide easily into
the coupling. Do not force engagement.
(3) Install top-left and bottom-right mounting
screws first, and tighten securely.
(4) Make sure all line connections are tight.
(5) Operate the pump after installing and
check operation of lift and steering systems.
(6) Install a pressure gage (2000 psi) in
pressure line between pump and control valve and check
pressure with engine running at maximum throttle and
with steer wheel held in either extreme right or left
position. Observe gage for a reading of 1200- to 1400psi.
2-9
2-11. Hydraulic Lift Assembly
a. Description. The hydraulic lift assembly consists
of hydraulic cylinder, carriage and inner and outer masts
with wear plate in the sliding channels to provide
maximum ease of movement.
b. Removal. Refer to figure 2-5 and remove as
follows:
(1) Remove lift forks (TM 10-3930-618-20).
(2) Detach tilt cylinders from mast. brackets
(para 2-12).
(3) Attach chain hoist to lifting eyes on the
back of outer mast and raise mast assembly enough to
take weight off pivot pins.
(4) Remove lock wires from capscrews.
Remove capscrews, lockwashers, and remove pivot
pins.
(5) Lift mast assembly free of truck.
1 Coupling
2 Lockwasher
3 Screw
4 Screw
5 Lockwasher
6 Pump
Figure 2-4. Hydraulic pump removal and installation.
2-10
Figure 2-5. Hydraulic lift assembly removal and installation.
2-11
b. Installation.
(1) Reverse procedures in a above.
(2) Make sure the rear pin retainer is
positioned properly so the screw can be easily installed.
(3) Make sure that hydraulic line connections
are tight.
(4) Refill hydraulic tank.
(5) Operate the cylinders and check carefully
for leaks before installing the cowls.
(6) Check to be sure both cylinders bottom
simultaneously.
c. The correct degree of tilt is 3° forward and 10°
backward for correct adjustment procedures, refer to TM
10-3930-618-20.
2-13. Hydraulic Control Valve and Levers
a. Removal. Refer to figure 2-7 and remove the
hydraulic control valve as follows:
(1) Remove seat and right-hand side panel.
(2) Remove pins attaching levers (6) to valve
plungers.
(3) Disconnect all hydraulic lines at control
valve.
(4) Remove nuts (10) and washers (11) and
remove control valve assembly from bracket (13).
c. Installation.
Install hydraulic lift mast by
reversing procedures in b above.
2-12. Tilt Cylinders
a. Removal. Refer to figure 2-6 and remove tilt
cylinder assemblies as follows:
(1) Operate the tilt control lever to put the
mast in forward position. Hold the mast in forward
position with a chain hoist.
(2) Remove the cotter pin and pull out the pin
attaching the cylinder yoke to the carriage.
(3) Disconnect the hydraulic lines at the tilt
cylinder.
(4) Remove the screw and pin retainer from
the tilt cylinder rear mounting bracket and pivot shaft.
(5) Insert a drift in the hole (provided in the
pivot shaft) and remove the pivot shaft. Lift the cylinder
from the truck.
Figure 2-6. Tilt cylinder removal and installation.
2-12
1 Knob
2 Knob
3 Bushing
4 Handle
5 Nut
6 Lever
7 Link
8 Bushing
9 Flat washer
10 Nut
11 Lockwasher
12 Control valve
13 Bracket
14 Bracket
15 Screw
16 Lockwasher
Figure 2-7. Hydraulic control valve removal and installation.
(5) Replace nuts (10) and washers (11) or
screws 115) to hold bracket (14) in place.
b. Removal (Control levers)
(1) Remove links (7) attaching levers (6) to
bracket (14).
(2) Remove lower nuts (5) and lockwashers
(16) from handles (4). Loosen upper nuts (5) and screw
handles from levers.
(3) Remove knobs (1 and 2) from handles.
c. Installation. Install hydraulic control valve by
reversing the procedure in a & b above.
2-14. Steering Axle Assembly
a. Removal. Refer to figure 2-8 and proceed
a follows:
(1) Raise rear end of truck with chain hoist to
a workable height and support in this position with blocks
or other authorized safe means.
(2) Place a suitable jack under the steering
axle to raise it slightly. This removes weight stress from
the trunnion supports and supports axle during removal.
(3) Detach steering yoke from ball stud on
pivot arm.
(4) Remove from capscrews attaching the
trunnion support assemblies.
(5) Lower axle assembly to ground.
2-13
Figure 2-8. Steering axle assembly, removal and installation.
2-14
b. Installation. Install the steering axle assembly by
reversing the procedure in a above.
2-15. Drive Axle Assembly
a. Removal The complete drive unit, including
wheels and tires, can be removed as a unit. Proceed as
follows:
(1) Remove hydraulic lift assembly (para 2-11)
(2) Remove propeller shaft (para 5-21).
(3) Remove hand brake assembly (para 5-12)
NOTE
If desired, detach universal joint from
pinion flange and leave handbrake
assembly installed.
2-15
(4) Disconnect hydraulic brake line at tee on
right-hand axle mounting support.
(5) Attach hoist to front of truck and raise
trucks just enough to take weight off of axle housings.
(6) Remove (2) bolts and nuts that attach the
differential housing to the truck frame.
(7) Remove nuts and lockwashers from Ubolts. Pull U-bolts from axle supports.
(8) Raise front of truck until supports clear
axle housings and roll drive unit from beneath truck.
Figure 2-9. Drive axle assembly removal and installation.
2-16
b.
Installation.
Install the drive axle
assembly on the truck frame by reversing procedure in a above.
2-17
CHAPTER 3
REPAIR OF POWER PLANT
Section I. REPAIR OF ENGINE ELECTRICAL SYSTEM
b. Disassembly. Refer to figure 3-1.
(1) Remove the four thru-bolts from the
alternator assembly
NOTE
Place a scribe mark on the stator and
end frames to aid in locating the
parts in the same position during
reassembly.
3-1. General
This section contains information useful to direct
and
general support maintenance personnel in their
performance of maintenance of the engine electrical
system.
3-2. Alternator
a. Removal and Installation. Remove or install the
alternator as directed in TM 10-3930-618-20.
Figure 3-1. Alternator, exploded view.
(2) Separate the front end frame and the rotor
assembly from the stator assembly. Pry them apart at
the stator slot with a screw driver.
(3) Place the rotor in a vise and tighten just
enough to permit removal of the shaft nut. Remove the
shaft nut, washer, pulley, fan and collar.
(4) Separate the rotor from the front end
frame, removing key.
(5) Remove retainer, collar, gasket and
bearing from end frame.
(6) Remove stator from rear end frame.
(7) Remove rear end frame bearing and
3-1
retainer from end frame. Place a piece of tape over
the bearing and over the slip ring assembly on the
rotor shaft.
(8) Remove brushholder, brushes
and
springs.
(9) Remove capacitor, diodes, and heat sink
from end frame.
(CHECK FOR GROUNDS)
NOTE
Do not wash alternator parts in a
cleaning solvent.
c. Cleaning. Clean all parts with a dry, lint-i/ce
cloth. Use filtered compressed air to blow dust dirt from
end frames.
d. Inspect and Repair.
A. ROTOR
B. STATOR
ME 3930-618-34/3- 2
Figure 3-2. Checking rotor and stator for shorts,
grounds, and open circuits.
3-2
CAUTION
Do not touch test probes to polished
mating surfaces.
(1) Rotor. Refer to figure 3-2 and perform the
following checks:
(a) Grounds. Connect 1 10-volt test
lamp or an ohmmeter from either slipring to the rotor
shaft or to the rotor poles. If the lamp lights, or if
ohmmeter reading is low, it indicates the field is
grounded.
(b) Open windings. Connect test lamp
or ohmmeter to each slipring and if lamp fails to light or if
ohmmeter reading is high (infinite), winding is open.
(c) Short-circuits. Connect a battery
and ohmmeter in series with two sliprings. Note the
ammeter reading. If reading is above 1.9-to 2.3ohms, it
indicates shorted windings.
(d) Field resistance.
Connect an
ohmmeter to the two sliprings and check the resistance
of the field. If the resistance reading is below 1.9-to
2.3ohms, the winding is shorted. Replace a defective
rotor as required.
(2) Stator. Refer to figure 3-2 and perform
following checks:
(a) Ground. Check stator windings with
a 110-volt test lamp or an ohmmeter. If the test lamp
lights, or if the meter reading is low when connected from
any stator lead and to the frame, the windings are
grounded.
(b) Open windings. Connect test lamp
or ohmmeter to any stator lead and to the frame. The
windings are open if the lamp fails to light or if the meter
reading is high when successively connected between
each pair of stator leads.
Replace stator having
grounded or open windings.
NOTE
Due to low resistance of the stator
windings, it is difficult to locate a
short circuit in the windings, without
the use of laboratory test equipment.
Shorted Stator windings are indicated
if all other electrical checks are
normal but alternator does not supply
rated output.
(3) Diodes. Refer to figure 3-3 and check
each diode electrically for a shorted or open condition by
any one of the following methods:
Figure 3-3. Checking heat sink diodes.
(a) Ohmmeter method.
Use an
ohmmeter with a 11/2-volt cell and use the lowest range
scale.
Disconnect stator from the heat sink diodes.
1. Connect one ohmmeter lead to the
heat sink and the other one to the diode lead and note
the reading. Reverse the ohmmeter lead connections
and check the reading.
2. If both readings are either very low
or very high, the diode is defective. A good diode is
indicated by one low reading and one high reading.
Check the two remaining heat sink diodes in same
manner.
3. Check the end frame diodes in the
same manner as the heat sink diodes. However,
connect
3-3
(b) Press the bearing out from the
slipring rear frame with a tube or collar that fits just inside
the rear frame housing. Press the bearing out from
outside the housing toward the inside.
(c)
Press in the new bearing with a flat
plate. Press in from outside of the rear frame until the
bearing is flush with the outside of the rear frame.
To prevent breakage of the rear frame, support it on the
inside with a hollow cylinder. When installing the new
bearing, use extreme care to avoid misalignment or
other undue stress on the bearing. Saturate the felt seal
in OE 10 oil (MIL-L-21041, then reassemble felt seal
and steel retainer.
(8) Brush Replacement.
(a) When separating the slipring rear
frame from the rotor and front end frame assembly, the
brushes will drop down onto the shaft and come into
contact with the lubricant. If brushes are to be reused,
they must be thoroughly cleaned with a soft dry cloth.
Also.
clean the shaft thoroughly before beginning
reassembly.
(b) lnspect the brush springs for
evidence of any damage or corrosion. Be sure to
replace the brush springs if there is any doubt as to their
condition.
(c) When new brushes are required.
install them as follows: First, remove the two brush
holder screws, then remove the brush holder assembly
from the rear frame. After installing the springs and
brushes in the brush holder, insert a piece of straight
wire or pin into holes at the bottom of the holder to retain
brushes. Then install the brush holder assembly onto
the rear frame, noting carefully the proper alignment of
parts as shown in
one ohmmeter lead to the end frame and one to the
diode lead. Check all three diodes in the way previously
described.
(b) Test lamp method. Test lamp of not
more than 12-volts is required. Disconnect stator from
the heat sink diodes.
CAUTION
Do not use 110-volt test lamp to
check diodes.
1.
Connect the test lamp in the same
manner as the ohmmeter. If lamp lights in both checks
or fails to light in both checks, diode is defective. When
diode is not defective, the test lamp will light in only one
of two checks.
2. Check all diodes and replace
defective ones as required.
When a diode
(4) Diode replacement.
requires replacement. proceed as follows:
CAUTION
Do not hammer diodes into position
as the shock will damage them.
(a) Support the end frame or head sink
in a suitable tool and push out the old diode with an arbor
press or vise.
(b) Press the diode in with a suitable
tool which fits over the outer edge of the diode while
supporting the heat sink or end frame.
(5) Slipring.
(a) Clean. To clean sliprings, use 400grain or finer polishing cloth. Spin the rotor in a lathe or
by other means and hold the polishing cloth against the
sliprings until they are clean.
(b) Repair. Out of round or rough
sliprings should be trued to 0.002-inch maximum
indicator readings in a lathe. Remove just enough
material to make the rings smooth and round. Polish
with 400grain or finer polishing cloth and blow away all
dust.
(6) Bearing (drive bearing).
(a) The drive bearing can be removed
by detaching the retainer plate screws and then pressing
the bearing from the front frame.
(b) Check the bearing; if it is in
satisfactory condition, it can be reused. It should be
cleaned in an approved cleaning solvent and lubricated
¼ full with MILG-18709.
CAUTION
Do not overfill with lubricant as this could
cause the bearing to overheat.
(c) If a new bearing is required, press it
in with a tube or collar that just fits over the outer race. If
the felt seal is worn excessively or hardened, it is
recommended that a new retainer plate be in stalled.
(7) Bearing (Rear Frame).
(a) The slipring rear frame bearing
should be replaced if its grease supply ;is exhausted.
Never attempt to relubricate and reuse the bearing.
Figure 3-4. Brush holder assembly.
(9) Heat sink replacement.
(a) To replace the heat sink, remove the
"BAT" and "GRO" terminals from the end frame and the
screw attaching the condenser lead to heat sink.
3-4
(b) During reassembly, carefully note the
alignment of parts as shown in figure 3-1.
e. Alternator reassembly.
(1) The reassembly of the alternator is a reverse
of the disassembly (fig. 3-1).
(2) Avoid excessively tightening the rotor in a
vise as this could distort the entire rotor assembly. After
installing the pulley assembly, tighten the shaft nut to 5060 ft. lbs. Before installing the slipring end frame
assembly, remove the protective tape from the bearing
end shaft, making sure shaft is completely clean after
tape is removed.
(3) When alternator is assembled, withdraw the
brush retaining wire through the hole in the end frame,
allowing the brushes to contact the sliprings.
f. Alternator test.
(1) To check the alternator on a test bench,
make an electrical hook-up as shown in figure 3-5,
operate at specified speed and check for rated output.
See table 3-1.
(2) Adjust the load rheostat, if necessary, to
obtain, the desired output.
Figure 3-5. Checking alternator output.
Table 3-1. Alternator Specifications
Field current
(80F)
Rotation
viewing
D.E.
CW
Grd
Neg
Amps
1.9-2.3
Volts
12
Cold output
at specified voltage
Spec
volts
14.0
Amp
12
Approx.
R.P.M.
1100
Amp
42
Approx.
R.P.M.
6500
Rated
hot output
amp
42
(1) Secure starter motor in bench vise at drive
end of unit. Be careful not to damage drive end housing.
(2) Remove the two through bolts (15, fig. 3-6)
and slide commutator end frame (1) and field frame from
armature.
3-3. Starter Motor
a. Removal and Installation. Refer to TM 10-3930618-20 and remove or install the starter motor.
b. Disassembly. Disassembly should proceed only so far as is necessary to make repairs or
replace defective parts.
3-5
1 End frame
20 Drive mechanism
2 Brush holder
21 Washer
3 Spring
22 Screw
4 Brush holder
23 Washer
5 Brush
24 Bushing
6 Screw
25 Bearing assembly
7 Nut
26 End frame (drive housing)
8 Lead
27 Pin
9 Washer
28 Screw
10 Shaft
29 Insulator
11 Screw
30 Pole shoe
12 Holder
31 Washer
13 Screw
32 Screw
14 Washer
33 Stud
15 Through bolts
34 Grommet
16 Field coil
35 Washer
17 Spacer
36 Washer
18 Armature
37 Nut
19 Ken
38 Washer
Figure 3-6. Starter motor, disassembly and reassembly/
(3) Disconnect field lead from brush holders
(2 and 4) and remove commutator end frame (1) from
field frame.
(4) Brushes (5) brush holders 12 and 4) and
springs (3) can now be removed from commutator end
frame.
(5) Do not remove field coils. If tests indicate
coils are defective, replace starting motor.
(6) Remove terminal stud from field frame by
removing nuts (37), washers (35, 36, and 38) and rubber
grommet (34).
(7) Remove capscrews (22) which mount
center bushing (24) on drive end housing (26) and
remove housing from armature.
(8) Drive mechanism (20) is keyed onto
armature shaft and is removed by pressing off or using a
puller.
c. Cleaning, Inspection and Repair. Clean, inspect
and repair as directed in TM 5-764.
d. Reassembly.
(1) Install field frame terminal stud (33) and
then connect heavy field lead to stud (33).
(2) Install brush holders (2 and 4), brushes
(5), and springs (3) on commutator end frame (1).
Place end frame on field frame and connect
undergrounded brush leads to field coil terminals.
(3) Install center bearing (25) on armature
shaft with long side toward commutator end of armature.
(4) Install key (19) in armature shaft (18) and
3-6
press on drive mechanism (20). Apply thin coating of
grease before pressing on drive assembly.
NOTE
If drive mechanism is rotated to full
extended lock position on crew shaft
during
replacement
or
during
overhaul of cranking motor, do not
attempt to force it in the reverse
direction. Proceed to install drive
even though it is fully extended.
After starter motor is installed on
engine and the engine starts.
centrifugal force will demesh drive
pinion from flywheel ring gear in the
usual manner.
(5) Place drive end housing (26) on armature
shaft after placing a few drops of oil on bushing (24).
Then fasten center bearing (25) on drive housing (26).
(6) Place spacer (17) on commutator end of
armature shaft and install armature (18) complete with
drive housing (26) in field frame assembly.
While installing armature, pull commutator end frame
away from field frame and make certain brushes are
seated correctly on commutator.
(7) Replace end frame and position drive end
housing on field frame. Make certain both commutator
end frame and drive housing are correctly positioned on
field frame dowels (27). Then insert the through bolts
(15) and tighten securely.
3-4. Ignition Coil
Test the coil for grounded or open circuits by using a test
lamp as follows:
a. Primary Circuit Continuity Test.
(1) Check the primary circuit by placing the
test probes of a test light on the two primary terminals.
(2) If the lamp does not light the primary
circuit is open and the coil must be replaced.
b. Secondary Circuit Continuity Test.
(1) Check the secondary circuit by placing
one test probe of a test light on the high tension terminal
and the other test probe on one of the primary terminals.
(2) The lamp will not light but sparks will be
noted as the test probe is rubbed over the terminal.
If no sparks occur, the secondary circuit is open and the
coil must be replaced.
Section II. REPAIR OF COOLING SYSTEM
cooling fan to provide positive full airflow through radiator
core, a fan shroud is provided. An overflow tube
connected to filler neck leads to bottom of radiator.
Radiator incorporates a transmission oil cooler in bottom
tank. A double acting valve is provided in radiator cap
for relieving pressure due to expansion (from heating of
coolant) and allows atmospheric pressure to enter when
contraction (due to cooling of coolant) occurs.
b. Removal and Installation. Refer to TM 103930618-20.
c. Cleaning and Inspection. Refer to TM 1039 30618-20.
d. Repair.
(1) Radiator core. Use standard operating
procedures for repair of radiator core.
(2) Heat exchangers.
(a) Sweat heat exchanger loose from bottom of
radiator core.
(b) Plug one port of heat exchanger, then apply
controlled air pressure to remaining port.
NOTE
Place heat exchanger under water as
air pressure is applied to expedite
leak location.
(c) Mark leak (s), remove air pressure, and dry
surface of heat exchanger.
(d) Prepare surface of heat exchanger to
3-5. Description
The cooling system carries off excess heat from the
engine and holds engine at an efficient operating
temperature. System includes radiator, water pump,
engine temperature gauge and sending unit, thermostat,
cooling fan, and coolant passages in the cylinder block
and cylinder head. Centrifugal water pump, which is
driven by "V" belt from crankshaft pulley, draws coolant
from bottom of radiator to top of cylinder block, from
where there is forced circulation of coolant through
cylinder block and cylinder head. Coolant is discharged
from cylinder head into coolant outlet manifold and
passes through thermostat and tubing to upper tank of
radiator. Heat is removed from coolant as it passes from
top to bottom of radiator by air forced through radiator
core by pusher type cooling fan.
Engine has a pressure type cooling system which
permits higher coolant operating temperatures. It is
necessary to keep radiator cap turned on tightly at all
times to prevent loss of pressure. A thermostat, located
in the thermostat housing operates automatically to
maintain a minimum coolant operating temperature of
1650F. This section covers direct and general support
maintenance procedures authorized by the Maintenance
Allocation Chart.
3-6. Radiator
a. Description.
Fin and tube type radiator is
supported in truck frame and protected from damage by
a heavy grille mounted in the counterweight. In order for
3-7
(d) Install radiator cap, then test radiator
core. Do not exceed 10 psi of controlled air pressure.
(e) When leak is evident in radiator,
repair radiator as in d(1) above. Replace a radiator,
when heat exchanger or radiator core is beyond repair.
receive silver solder, solder leaks, then solder heat
exchanger to bottom of radiator core.
(3) Test.
(a) Use controlled air pressure.
(b) Plug one port of heat exchanger,
apply air pressure to the remaining port, then gradually
increase pressure to 30 psi.
(c) When leak is evident, repair heat
exchanger as in d(2) above.
Section III. REPAIR OF ENGINE FUEL SYSTEM
(h) Remove the two screws (57)
attaching throttle plate (56) to throttle shaft and remove
plate.
(i) From governor end of throttle shaft,
remove cotter pin (2) and retainer (3); slide governor
lever (5) and spring (4) off shaft (48). Note position of
spring and lever to insure correct reassembly.
(j) Drive roll pins (55) from shaft.
(k) Pull throttle shaft with lever from
throttle body. If is not necessary to remove throttle lever
from shaft unless the parts must be replaced.
(l) Remove both throttle shaft seals (9
and 46) and retainers (8 and 47) using end of a small
screwdriver to lift out parts.
(3) Disassembly fuel bowl body as follows:
(a) Remove drain plug (35) from bottom
of fuel bowl body.
(b) Remove passage plug (33) and fibre
washer (34) from bottom of fuel bowl body.
(c) Remove discharge jet (32) and fibre
washer (31) from passage in bottom of fuel bowl body.
(d) With a small screwdriver, remove
well vent jet (42) from center of large opening in
machined surface of fuel bowl.
(e) Remove main jet (28) and fibre
washer (29) from inside fuel bowl.
(f) Note position of choke bracket (27)
and choke shaft (24) to insure correct reassembly.
(g) Remove choke plate screws (39)
and lockwashers.
(h) Remove choke plate (38), choke
shaft (24) and lever.
(i) choke bracket by removing the two
capscrews (26).
(j) Drive out choke shaft hole plug (37)
by using a short length of ¼-inch rod inserted through
opposite shaft hole.
(k) Remove shaft seals (40) by using
end of a small screwdriver to lift out parts.
d. Cleaning and Inspection.
(1) Clean all metal parts thoroughly in an
approved cleaning solution, then rinse in cleaning solvent
(Spec. P-S-661).
3-7. General
This section will cover direct and general support
maintenance of the engine fuel system authorized by the
maintenance allocation chart, and includes the
carburetor, governor, and fuel tank.
3-8. Carburetor
a. Description. The carburetor is mounted directly)
to the intake manifold on the left side of the engine. The
throttle valve is controlled by the action of the accelerator
controls and the action of a variable speed governor. It
is of the single venturi, updraft type which mixes the
correct proportions of air and fuel to produce a highly
combustible mixture, which is then drawn into the intake
manifold. All mixture adjustments, except idle, are
controlled by fixed jets. The idle fuel adjusting screw
controls the fuel mixture for the idle system.
The idle throttle stop screw controls low engine rpm.
The air intake of the carburetor is provided with a choke
valve as an aid in starting a cold engine.
b. Removal. Refer to TM 10-3930-618-20.
c. Disassembly.
(1) Separate carburetor bodies as follows:
(a) Remove the four screws (15, fig. 37) and lockwashers which attach throttle body ( 11 to
fuel bowl (30).
(b) Separate throttle body from fuel
body and remove gasket.
(2) Disassemble throttle body as follows:
(a) Press screwdriver against the float
axle (21) at slotted side of float hinge bracket and force
axle through hinge bracket.
(b) Pull float axle out from opposite side
and remove float (20).
(c) Remote float valve and seat (17),
and waster , (16) from throttle body.
(d) Remove venturi 1191.
(e) Remove idle jet (44) from its
passage near float valve seat.
(f) Remove idle adjusting needle (13)
and spring (12) from front of throttle body.
(g) Unscrew throttle stop screw (54)
until threaded end is flush with the lever (51).
3-8
(2) Blow out all passages with compressed air
and make certain that all carbon deposits have been
removed from the throttle bore and idle ports.
(3) Inspect for float leaks and other damage.
(4) Inspect float axle bearings for excessive
wear.
(5) Inspect top side of float lever for wear
where it contacts the fuel valve needle.
(6) Inspect float axle for wear on bearing
surfaces.
(7) Inspect idle adjusting needle and spring
for wear or ridges on needle point, weak or bent spring,
and other damage.
(8) Inspect throttle plate for burred or
damaged edges.
CAUTION
Never clean a throttle plate with a buffing
wheel or sharp instrument.
(9) Inspect choke plate for bends, burrs or
damaged edges.
(10) Inspect choke shaft for bends and wear at
bearing surfaces.
(11) Inspect throttle shaft for wear at the
bearing surfaces.
(12) Check the jets for specified sizes
Idle jet ......................No. 15
Fuel valve.................No. 40
Main jet.....................No. 26
26 Discharge jet.......No. 65
Well vent jet.............No. 26
Idle air bleed............No. 25
Venturi.....................No. 20
(13) Replace defective parts as authorized.
e. Assembly. Before assembling the carburetor,
make certain all the above inspections and checks have
been completed. Check for correct location of parts (fig.
3-7).
(1) Assemble fuel bowl body as follows:
(a) Press the choke shaft (24) and
retainer (41) into the bowl bore until the retainer is flush
with the machined surface.
(b) In the opposite hole, install the shaft
hole plug (37) with a hammer.
(c) Install the choke bracket (27),
keeping in mind its position when removed.
(d) Insert the choke plate (38), poppet
valve first and stem down, into the air intake.
(e) Hold the choke plate up and insert
the choke shaft into place with the cutout section facing
up.
(f) Rotate the shaft to the closed
position, place the choke plate in the cutout section and
install the screws (39). Be sure the plate is properly
centered before tightening the screws.
(g) Install the main jet (28) and fibre
washer (29) in the fuel bowl.
(h) Install the well vent jet (42).
(i) Install the discharge jet (32) and
fibre washer (31) in the large threaded passage beneath
the fuel bowl; then install the fibre washer (34) and
passage plug (33).
(j) Install the drain plug (35) in the
bottom of the fuel bowl.
(2) Assemble throttle body as follows:
(a) Install throttle shaft seals (9 and 46),
open side out, followed by the retainers. Retainers must
be flush with throttle body.
(b) Insert the throttle shaft (48) with the
throttle lever into the throttle body.
(c) With the throttle shaft positioned
with the throttle lever down, install the roll pins (55) in the
governor end of the shaft until the bottom of the pin is
flush with the shaft.
(d) Install the governor lever up. Install
the coil spring in the same position as when it was
removed.
(e) Install the retainer (31 and the cotter
pin (2).
(f) Rotate the throttle shaft to closed
position, insert the throttle plate in the cutout section of
the shaft, holding the plate in position with the fingers.
(g) Start the throttle plate screws (57)
and tighten, being sure that the throttle plate is properly
centered in the throttle body bore.
NOTE
The screw holes in the throttle plate are
off center. Start the side of the throttle
plate with the shortest distance between
the screw holes and beveled edge into
place first. The throttle plate is made
with two opposite edges beveled to fit the
throttle body bore when the plate is
closed. The throttle plate will not close
tightly if installed upside down. Pressure
on the plate must be maintained with the
finger until the screws are tightened.
When properly installed, the side of the
throttle plate farthest away from the
mounting flange will be aligned with the
idle port when the plate is closed.
(h) Install the idle adjusting needle (13)
and friction spring (12) in the threaded passage in the
front of the throttle body. Seat the needle lightly and then
back out 1 1/4 full turns as a preliminary adjustment.
(i) Install the idle jet (44) in its
counterbored passage in the machined surface.
(i) Install the fuel valve and seat (17)
and the fibre washer (16).
(k) Install the fuel valve needle in the
seat, then install the float (20) and the float axle (21).
Make certain the float is free and is centered on the
throttle body.
(l) Check for correct level by inverting
the throttle body and measuring from the machined
surface of the body to the top side of the float bodies at
the highest point. The dimension should be 1.5/32 inch
±1/32 inch. To increase or decrease the distance
between the float body and the
3-9
(c) Hold the throttle lever in a closed
position and turn the throttle stop screw (54) in until it just
contacts the stop pin, then turn the screw in 1 ½
additional turns as a preliminary adjustment of the idle
speed.
f. Adjustment and Installation. Refer to TM
10-3930-618-20.
machine surface, use longnosed pliers and bend the
lever close to the float body.
(m) Insert the venturi (19) in the fuel
bowl bore, with the small opening down. The flat side of
the venturi must be toward the well vent jet.
(3) Assemble carburetor bodies as
follows: (a) Place a new gasket on the throttle
body.
(b) Place the fuel bowl on the throttle
body, install the four capscrews (15) and tighten them
evenly and firmly.
Key to figure 3-7
1 Lever and shaft assembly
2 Cotter pin
3 Retainer
4 Spring
5 Clamp lever
6 Screw
7 Spacer
8 Seal retainer
9 Shaft seal
10 Bearing
11 Body
12 Spring
13 Needle
14 Plug
15 Screw
16 Washer
17 Valve and seat
18 Gasket
19 Venturi
20 Float
21 Axle
22 Nut
23 Screw
24 Choke shaft
25 Screw
26 Screw
27 Choke bracket
28 Main jet
29 Washer
30 Bowl
31 Washer
32 Discharge jet
33 Plug
34 Washer
35 Drain plug
36 Plug
37 Plug
38 Choke plate
39 Screw
40 Packing washer
41 Retainer
42 Well vent jet
43 Clip
44 Idle jet
45 Bearing
46 Shaft seal
47 Seal retainer
48 Throttle shaft
49 Bushing
50 Screw
51 Throttle lever
52 Retainer
53 Cotter pin
54 Throttle stop screw
55 Pin
56 Throttle plate
57 Screw
58 Gasket
3-10
Figure 3-7. Carburetor disassembly.
3-11
and throttle lever (23) and press the shaft out of the
lever.
(7) Press the bearing, seal, and retainer off
the lever shaft.
(8) Remove the spider shaft bushing (35)
from the governor body.
(9) Press the lever shaft bottom bushing (31)
out of the governor body.
d. Cleaning and Inspection.
(1) Wash all parts in cleaning solvent (Spec.
P-S-661) and thoroughly dry with compressed air.
(2) Check lever shaft and bearing for worn
areas and score marks. Replace if lever shaft does not
rotate freely in the governor body.
(3) Replace the lever shaft oil seal.
(4) Slide thrust sleeve and bearing on the
spider shaft and check for freeness.
(5) Check the drive gear (43) for worn or
chipped teeth. Check the gear bearing surface for score
marks. Replace the gear if necessary.
(6) If the governor weights (39) are too loose
or bind on the pivot pins, make the necessary repairs, or
replace the assembly.
(7) Check the drive gear bearing and the
thrust washer for worn spots or score marks. I’ the
bearing is loose, install a new bearing in the adapter.
(8) Replace the governor spring (17) if it is
worn or weak.
(9) Install new gasket.
e. Assembly.
(1) To replace the adapter bearing (9), locate
the bearing with the oil hole up and press into place to
the same position as the bearing which was removed.
(2) Press bearing (28) on the lever shaft (20)
until it seats on the snapring (29) and then follow with the
oil seal (26) and retainer (27).
(3) Install the throttle lever (23) on the lever
shaft (20) and secure both parts with the roll pin (24).
(4) Press the spider shaft bushing (35), into
the governor housing flush with the open end of the bore.
Normal clearance between the bushing and the shaft is
0.002 inch to 0.004 inch.
(5) Press the lever shaft bushing (31) into the
governor housing; but, do not press all the way in at this
time.
(6) Hold the yoke (36) in the governor
housing, install the lever (23) and shaft (20), sliding the
shaft through the yoke.
(7) Position the yoke on the shaft. install and
tighten the fasteners (37).
(8) Continue pressing the lever shaft bushing
into the governor housing until there is between 0.005inch and 0.015-inch end plan. Then paint over the
bushing with a sealing compound.
3-9. Governor
a. Description.
The engine governor is a
mechanical spring loaded device installed on the engine
to prevent overspeeding. It consists of a drive gear and
a set of weights arranged around a shaft in a spider
assembly. The unit is mounted on the timing gear cover
and is driven by a gear meshing with the camshaft gear.
Centrifugal force created by rotation causes the governor
weights to pivot outward on their retaining pins. The
outward movement of the weights pushes a thrust sleeve
against a yoke, which in turn, transfers this movement
through the governor control rod to the throttle valve in
the carburetor. The governor weights move outward
until the pressure on the thrust sleeve is strong enough
to overcome the spring tension on the throttle lever.
When this condition occurs, governor force, through the
control rod to the throttle valve, prevents the entrance of
more fuel to the manifold, thus preventing the engine
from exceeding its maximum governed speed of 2200
rpm.
b. Removal.
(1) Clean outside of the governor housing and
the surrounding area to be certain that no loose dirt will
enter the governor assembly.
(2) Remove the ignition coil from the adapter
cover (TM 10-3930-618-20).
(3) Remove the governor spring (17, fig. 3-8)
from the adjusting screw (18) and disconnect the throttle
lever (23) from the control rod 13).
(4) Remove the two capscrews from the
adapter assembly (11) mounting flange.
Lift the
governor body away from the timing gear housing.
(5) Slide the thrust bearing and sleeve (38) off
the weight assembly shaft (40) and then work the drive
gear (43) free of the adapter.
(6) Remove the two capscrews (13) and
lockwashers (12) attaching adapter (11) to body (30) and
timing gear housing, and remove the adapter and thrust
washer t 10).
c. Disassembly.
(1) Remove the adapter cover to remove the
adapter bearing 19i.
(2) To remove the governor weights (39) from
the spider assembly (40). slip the pin clips (42) from the
governor weight pivot pins, drive out the pins and remove
the weight from the spider.
(3) Press the drive gear (43) from the spider
shaft (40).
(4) Remove the two fasteners (37) which
secure the yoke (36) to the lever shaft (20).
(5) Pull the lever shaft out of the governor
body along with the bearing (28), seal (26), and retainer
(27). Remove the yoke from the governor bode.
(6) Drive the pin (24) out of the lever shaft
3-12
f. Installation.
(1) Install the governor on the engine by a direct
reversal of the procedures in b above. Be sure to use
new gasket.
1 Ball joint
2 Nut
3 Control rod
4 Nut
5 Lockwasher
6 Nut
7 Gasket
8 Dowel pin
9 Bearing
10 Thrust washer
11 Adapter assembly
12 Lockwasher
13 Capscrew
14 Shaft
15 Nut
(2) Install the throttle control rod on the
throttle lever.
(3) After installation, refer to TM 10-3930618-20 for adjustment instructions.
16 Nut
17 Spring
18 Adjusting screw
19 Nut
20 Shaft
21 Lockwasher
22 Nut
23 Throttle lever
24 Roll pin
25 Seal and retainer kit
26 Seal
27 Retainer
28 Bearing
29 Snapring
30 Body
31 Bushing
32 Washer, copper
33 Gasket
34 Disc
35 Bushing
36 Yoke
37 Fastener
38 Sleeve and bearing assembly
39 Weight
40 Spider and shaft assembly
41 Pin
42 Clip
43 Drive gear
Figure 3-8. Governor disassembly.
3-13
(1) Flush tank with solvent and dry with
compressed air.
(2) Inspect tank for rust, cracked seams, or
damaged threads.
(3) Inspect accessories for damage or
corrosion.
d. Repair.
(1) I damage is such that welding can be used
to repair the tank, be sure to flush tank thoroughly to
remove all traces of explosive solvents and fuel, both
liquid and vapor.
(2) If damage is beyond reasonable welding
repair, replace tank and accessories as authorized.
3-10. Fuel Tank
a. Removal and Installation. See TM 10-3930618-20.
b. Disassembly.
(1) Remove drain plug (16, fig. 3-9).
(2) Remove filler cap (10) assembly by
unscrewing from top of tank.
(3) Remove five screws (23) and lockwashers
which mount fuel gauge sending unit (18) in fuel tank,
and carefully lift unit out of tank. Be careful not to bend
the float arm during removal or installation.
c. Cleaning and Inspection.
1 Clamp
2 Lockwasher
3 Capscrew
4 Fuel line
5 Elbow
6 Plug
7 Washer
8 Lockwasher
9 Capscrew
10 Filler cap and screen
11 Fuel tank
12 Guard
13 Lockwasher
14 Capscrew
15 Drain plug
16 Drain plug
17 Gasket
18 Fuel sender
19 Boot
20 Lockwasher
21 Nut
22 Fuel gage
23 Screw
24 Washer
25 Lockwasher
26 Capscrew
Figure 3-9. Fuel tank.
3-14
Section IV. REPAIR OF ENGINE LUBRICATION SYSTEM
c. Installation.
(1) Cement new gaskets (1, fig. 3-10) to oil
pan side rails.
(2) Outer oil seal at rear of engine should be
replaced when engine is overhauled. If engine has not
been overhauled, inspect lower portion to make certain it
is in good condition. If outer seal has be to replaced, it
will be necessary to remove flywheel housing (para 326).
(3) Oil pan front gasket is lower portion of
cylinder block to front plate assembly gasket. When
engine is overhauled, new gasket should be cemented to
rear of front plate assembly before it is secured to front
of cylinder block. If engine has not been overhauled and
oil pan portion of gasket is damaged, scrape away
gasket as far as cylinder block rails. Cut lower portion
from new gasket and cement in position on front plate
assembly.
(4) Before installing oil pan, place a small
quantity of nonhardening sealing compound in corners
formed by flywheel housing and cylinder block rails, and
front plate assembly and cylinder block rails, to eliminate
possibility of oil leaks at these points.
(5) Position oil pan on cylinder block and
secure in place with capscrews and lockwashers.
Torque capscrews to 18-21 ft-lbs.
CAUTION
Be sure to use copper washers on
lower three capscrews in front of oil
pan. These three capscrews extend
into oil pan and copper washers
prevent oil leakage past capscrew
threads.
(6) Install drain plug in oil pan.
(7) If engine has not been removed from
truck, install steering axle assembly by a direct reversal
of removal procedure.
(8) Install rear grille in counterweight.
(9) Replace oil filter element and fill
crankcase to correct oil level.
(10) Run engine and check for oil leaks oil pan
and at filter.
3-11. General
This section will cover direct support maintenance of the
engine lubrication system authorized by the maintenance
allocation chart, and includes the oil pan, oil pressure
relief valve, and oil pump. The oil pressure relief valve
has an external adjustment that direct support may use
to assist in making determination of internal bearing
failure (low oil pressure), or clogged passages (high
pressure).
3-12. Oil Pan a. Removal and Inspection.
NOTE
Oil pan can be removed from engine
with engine-either installed in truck
or out of truck. If engine has already
been removed from truck, disregard
(1) through (4) below.
(1) Run engine until normal operating
temperature is reached.
(2) Remove drain plug (10, fig. 3-10) and
allow all engine oil to drain.
(3) Remove radiator grille from counterweight
(ref. TM 10-3930-618-20).
(4) Raise back of truck and remove steering
axle assembly (para 2-14) to allow sufficient room for
removal of oil pan.
NOTE
It will be necessary to work through
the
grille
opening
in
the
counterweight in order to remove the
front oil pan capscrews.
(5) Remove capscrews (8) from front of oil
pan and pan side flanges. Remove oil pan.
(6) Wash oil pan with cleaning solvent (Spec.
P-S-661) to remove all dirt and sludge.
(7) Inspect drain plug boss for evidence of
leakage.
(8) Repair by welding or hard soldering.
WARNING
Be certain that all traces of oil and
cleaning solvents have been removed
from the oil pan and the surrounding
area before any heat or flame is used.
3-15
1 Gasket
2 Breather cap
3 Filler tube
4 Oil level gauge
5 Oil seal
6 Adapter
7 Lockwasher
8 Capscrew
9 Gasket
10 Drain plug
11 Oil pan
Figure 3-10. Oil pan removal and installation.
occurs when starting a cold engine. Surrounding lower
part of oil pump is a fine mesh screen to keep any large
foreign object from entering oil inlet opening and
damaging pump.
b. Removal. Oil pump can be removed from
engine without removing engine from truck. Follow
procedure outlined below. If engine has already been
removed, disregard (1) and (2).
(1) Distributor is driven by means of an offset
slot at upper end of oil pump driven gear (1, fig. 3-11).
Because of offset, distributor can be mounted in only one
position. Therefore, it is recommended that distributor
rotor be positioned to fire on No. 1 cylinder before
removing oil pump from cylinder block. This can be
accomplished by positioning No.
1 piston on
compression stroke with timing mark "IGN" in center of
timing hole in flywheel housing. In this position, piston is
before top dead center. Mark side of distributor housing
to indicate position of rotor.
3-13. Oil Pump
a. Description. Lubricating oil pump is the positive
drive gear type consisting of a single cast pump housing
and mounting extension with a precision cavity to receive
the two pump gears, and attached to the crankcase
flange by two capscrews. Oil pump drive gear meshes
with and is driven by an integral helical gear on engine
camshaft. Oil pump driving gear is pinned to the upper
end of pump driving shaft and pump drive gear is
pressed onto lower end of driving shaft. Pump idler gear
is pressed onto idler gear shaft which rotates in pump
body. Idler gear is retained in pump body by bottom
cover in which is located entrance for oil from oil pan. Oil
is picked up by the pump gears and is forced into a tube
assembly which conducts it to a passage in the filter
base. Connected to the oil discharge passage of the oil
pump body, is a sleevetype relief valve which will bypass
oil back to oil pan when discharge pressure exceeds 7090 psi, thus eliminating undue wear on pump gears
caused by excessively high discharge pressure which
3-16
1 Drive gear
2 Pin
3 Drive shaft
4 Body
5 Roll pin
6 Valve piston
Valve spring
8 Spring retainer
9 Cover
10 Lockwasher
11 Capscrew
12 Screen
13 Lockwire
14 Idler shaft
15 Pump gears
16 Capscrew
17 Lockwasher
Figure 3-11. Oil pump.
oil pressure can be attributed to pump. To disassemble
pump, proceed as follows:
(1) Remove suction screen retainer wire (13)
and remove screen (12).
(2) Remove capscrews (11) and lockwashers
(10) securing pump cover (9) to pump body (4), and
remove cover.
(3) Remove pump gears (15) and idler shaft
(14) from pump body.
(4) Place pump assembly in position on a
press
NOTE
If both oil pump and distributor are
removed, as at engine overhaul. refer
to g below for installation procedure.
(2) Remove oil pan (para 3-12).
(3) Remove the two capscrews (16) and
lockwashers (17) which secure oil pump to cylinder
block. Withdraw pump from cylinder block.
c. Disassembly.
Disassembly of oil pump
advisable whenever the engine is overhauled or drop in
3-17
from pump driving gear and pump body. d. Cleaning
and Inspection. If dirt and sludge are allowed to
accumulate in engine lubricating system, oil pump wear
may be rather pronounced in a comparatively short time.
When oil is kept clean and oil filter has been properly
serviced wear on these parts should be very slight.
Wash all oil pump components in clean solvent, and
thoroughly inspect and check parts as follows:
(1) Inspect pump gear teeth, inside of pump
body, and inner face of cover for wear and scoring. Gear
teeth, inside of pump body, and inner face of cover must
be smooth with no scratches, score marks, or rough
spots. Also, inspect pump shafts and shaft bores in
pump body for excessive radial clearance (fig. 3-12)
between pump gears and pump body (0.001-inch to
0.002-inch). End clearance (between pump gears and
pump cover) of gears in pump body is 0.002-inch - 0.
004-inch, and must not exceed 0.006-inch. To check
clearance, lay pump cover across pump body. Insert a
feeler gage between pump cover plate and pump gears.
Backlash between pump gears can be checked with a
feeler gage and should not exceed 0.020-inch.
0.004inch. Specified diameter of both pump drive shaft
and idler gear shaft is 0.4990-inch - 0.4995-inch. Pump
housing bore is 0.5005-inch - 0.5015 -inch; idler shaft
bore is 0.500-inch - 0.501-inch. If parts are worn or
damaged, replace pump.
(3) Thoroughly clean oil pump suction screen.
e. Assembly. Refer to figure 3-11 for relative
position of parts and assemble pump as follows:
(1) When installing gears on idler shaft (14)
or drive shaft (3), press shaft gear into gear until end is
approximately flush with end of gear.
CAUTION
Shaft must not protrude past oil
pump cover end of gear.
(2) Lubricate pump drive shaft and insert (with
drive gear in position) into bore in pump body.
(3) Place pump body in position in a press,
supporting assembly on drive gear end of shaft. Place
pump driving gear in position! or: upper end of shaft,
aligning pinhole in gear ,with hole in shaft. Press gear
onto shaft until pinhole in gear and shaft are aligned.
Install new roll pin.
(4) Lubricate idler gear shaft (4) and install
pump gears (15) and shaft in position in pump body.
Check dimension between gears and bottom face of
pump body. End clearance of gears should be 0.002inch - 0.004-inch.
(5) Place pump cover (9) in position on pump
body (4) and secure with the capscrews (11) and
lockwashers (10).
NOTE
No gasket is required between cover
and pump body.
(6) Place pump suction screen (12) in position
on bottom of pump body and secure with screen
retaining wire (13).
(7) After pump is completely assembled, it
must turn freely when rotating drive gear (1) by hand.
f. Installation.
The
following
installation
instructions apply when engine has not been
disassembled for complete overhaul or when oil pump
has been removed with engine in truck. For pump
installation instructions at engine overhaul. refer to g
below.
(1) Make certain distributor rotor is aligned
with reference mark made on side of distributor housing
as instructed in b (1) above.
(2) Before installing oil pump in cylinder block,
use dial as illustrated in figure 3-13 to position offset of
pump drive gear to the right and toward the rear of
cylinder block so that slot will be at an angle of 5: 30-to
11: 30-o’clock.
Figure 3-12. Checking oil pump radial clearance.
(2) Inspect pump shafts for wear with a
micrometer and pump body wear with a feeler gage.
Inspect for excessive wear or scoring and replace if
necessary. Specified clearance between pump drive
shaft and pump housing bore is 0.0010-inch - 0.0025inch and must not exceed 0.004 - 0.006-inch. Specified
clearance between idler gear shaft and pump housing
bore is 0.0005 inch - 0.0029-inch, and must not exceed
3-18
flange and screw nut into flange to a point where tube
can still be turned.
(c) Cement a new gasket on flange.
(9) Position assembled flange, relief valve,
and tube b, inserting rear end of tube in cylinder block at
No. 6 main bearing cap and placing flange against oil
pump with relief valve down.
(10)
Start rear tube nut and tighten
securely. Install and tighten the two flanges to oil pump
retaining capscrews and lockwashers. Torque to 11-13
ft.-lbs. Securely tighten front tube nut.
(11) Install oil pan (para 3-12).
g. Installation After Engine Overhaul.
During
engine overhaul, distributor and oil pump are removed
from cylinder block. In order to mesh oil pump drive gear
with gear on camshaft in original factory location, so rotor
in distributor will point to No. 1 cylinder spark plug wire,
proceed as follows:
(1) Rotate crankshaft in direction of engine
rotation until No. 1 cylinder exhaust valve lobe on
camshaft points horizontally to side of cylinder block.
Whenever No. 1 cylinder exhaust valve camshaft lobe is
in this position, piston is on compression stroke near or
at top dead center and timing mark stamped on flywheel
should be in timing hole in flywheel housing.
Figure 3-13. Positioning drive gear offset slot.
(3) Insert oil pump in cylinder block with drive
gear positioned as indicated in (2) above and mesh it
with gear on camshaft. Install one oil pump retaining
capscrew and lockwasher and tighten only enough to
hold pump in place.
CAUTION
It is possible oil pump drive gear
engaged gear on camshaft one tooth
one way or the other from correct
position and tang on distributor drive
did not engage drive slot in pump
gear; therefore, if pump retaining
capscrews are tightened securely at
this time, undue strain will be placed
on distributor and advance arm
assembly.
(4) After oil pump is in mesh with gear on
camshaft, check to make certain distributor drive has
engaged slot in pump drive gear and rotor is pointing to
reference mark made on side of distributor housing.
(5) Install cap on distributor.
CAUTION
Overtightening may break mounting
flange. Note that flange is not flush
with cylinder block.
(6) Install second pump retaining capscrew
and lockwasher and tighten both capscrews to 1821 ft.lbs. torque.
(7) After pump is secured in position, check
gear backlash between pump drive gear and gear on
camshaft. Gear backlash is 0.004-inch -0.010inch, and
can be checked through opening at fuel pump mounting
pad.
(8) Assemble oil relief valve mounting flange,
relief valve, and oil tube assembly as follows:
(a) Place lockwasher on relief valve and
screw it into flange. Torque valve to 40-50 ft.-lbs. and
lock in position by bending one tab against relief valve
and a second tab against flange.
(b) Position oil tube assembly (straight section) in
NOTE
Number 1 cylinder exhaust valve
camshaft lobe is first lobe from front of
engine.
(2) Position offset slot of oil pump drive gear.
Refer to f (2) above.
(3) Insert oil pump in cylinder block with drive
gear position as indicated in f (2) above and mesh it with
gear on camshaft. Note that as pump drive gear meshes
with camshaft gear, it will rotate slightly because gears
are helical type. When pump gear is fully engaged with
cam gear, slot will be positioned at an angle of 4: 00 10: 00-o’clock (fig. 3-13). This is correct position for
slot in pump drive gear to drive distributor. Install
capscrew finger tight to hold pump in position.
(4) Insert distributor into cylinder block and
rotate until offset tang on distributor drive engages slot in
pump drive gear. In this position rotor will be pointing to
No. 1 cylinder spark plug wire in distributor cap.
(5) Complete installation of oil pump as
outlined in f above.
3-14. Oil Pressure Relief Valve
a. Description.
Stabilized oil pressure is
maintained in engine lubrication system by an adjustable
oil pressure regulating valve located in main oil gallery at
front left corner of cylinder block. This valve is factory
set to open at 35 to 40 psi. When oil pressure at relief
valve exceeds its regulated pressure setting, plunger
opens and excess oil bypasses through lower drilled
capscrew.
3-19
The drilled capscrew secures camshaft thrust plate to
front of cylinder block, and serves to lubricate gear train.
Pressure relief valve should require very little attention
under normal conditions. If engine lubricating system
allowed to sludge, valve may not work properly. If
plunger binds in open position, a sharp drop in engine oil
pressure will occur; or, if plunger binds in closed position,
a sharp rise in engine oil pressure will occur. If oil
pressure should rise or drop sharply, relief valve must be
disassembled and checked for damage or sludge.
Whenever oil pump or engine is disassembled. all
components of oil pressure relief valve assembly should
also be removed, thoroughly cleaned, and inspected.
NOTE
A gasket between adjusting screw
locknut and cylinder block is not
required because of nylon plug
located in side of adjusting screw
which prevents oil leakage past
threads.
plunger and plunger spring in position in cylinder block.
(2) Install pressure regulating valve adjusting
screw and locknut. Make certain valve adjusting screw
is turned into cylinder block same number of turns
required for removal.
(3) Start engine and operate at about one-half
throttle. Observe engine oil pressure gauge, and adjust
oil pressure regulating valve to obtain a reading of
approximately 15-psi on gauge. After engine reaches
normal operating temperature. operate engine at high
idle speed, adjust pressure regulating valve to obtain a
reading of 35-40 psi on oil pressure gauge, and tighten
locknut. No further adjustment of valve should be
necessary.
(4) After engine has been run-in, oil pressure
operating range (with stabilized engine temperature)
is 25- to 35-psi at rated engine speed.
b. Removal and Inspection.
(1) Loosen locknut (fig. 3-14) and remove
adjusting screw from cylinder block. While removing
adjusting screw, count number of turns required for
removal.
(2) Remove valve spring and plunger from
cylinder block.
(3) Wash all parts thoroughly in (Spec. PD680) and inspect. Replace any worn or damaged parts.
(4) Inspect valve seat in cylinder block and
clean if necessary.
c. Installation and Adjustment.
(1) Lubricate plunger with clean oil and install
Figure 3-14. Oil pressure relief valve.
Section V. REPAIR OF TORQUE CONVERTER AND PUMP
b. Test.
(1) Pump pressure.
To check pump pressure. install a
(a)
pressure gauge calibrated to 300-psi, in the port marked
"P" on the right side of the transmission. Leave the
transmission in neutral and start the engine. Accelerate
the engine to full governed speed and note the pressure
indicated on the pressure gauge (fig. 3-15).
3-15. Torque Converter and Pump
a. General. The "Power Shift" is dependent upon
correct operating pressures for efficient operation. If in
doubt, the pressures should be checked.
for the
following: Pump pressure, converter pressure, clutch
pack pressure, and clutch cooling oil pressure.
NOTE
Oil temperature should be 80° to 100°
F, when checking pressure at idle
speed.
3-20
pump, clogged converter orifice in pump collector ring or
a faulty cooler by-pass valve.
(3) Clutch pressure (at stall).
(a) To check clutch pressures; install a
pressure gauge in the front port on top of the
Figure 3-16. Checking clutch pressure.
(b) Check clutch pressure in forward
and reverse direction by the following method. Position
truck against wall and apply both the parking and the foot
brake-drive wheels must be locked. Accelerate engine
momentarily to wide open throttle with truck in a stalled
condition. Note the pressure indicated on the pressure
gauge. Engine rpm should not exceed 1500.
(c) If the reading is not below 65-psi, or
does not go above normal pump pressure, the pressure
in the clutch circuit is normal. Pressure should never be
below 65-psi.
(d) If the pressure is below 65-psi,
check for low oil level, restricted lines or passages,
damaged collector rings, faulty or incorrectly adjusted
selector valve, faulty pump or excessive leaks in the
clutch drum assembly. (4)
Clutch
pressure(Free
running). To check the clutch pressure with the drive
wheels free running, the following instructions are to be
used.
(a) Raise both drive wheels off floor and
block securely with both wheels free to rotate.
(b) Hold inching pedal up so inching
valve plunger cannot move.
(c) Run engine at full governed speed
with shift lever in either forward or reverse position.
Check pressure in both directions.
(d) If pressure is abnormal, check
ME 3930-618-34/3-15
Figure 3-15. Checking pump and converter pressure.
(b) If the pump pressure is between
100-psi and 140-psi, the pump is in normal operating
condition.
(c) If the pump pressure is over 150-psi,
check the regulator valve spring and spool; check the
cooler by-pass and check for restricted lines and
passages.
(d) If the pump pressure is below 100psi, check for low oil level, a faulty pump, excessive line
leakage, a faulty directional valve, or clogged inlet filter.
(2) Torque converter pressure.
(a) To check converter pressure, install
a pressure gauge calibrated to 300-psi, in the port
marked "C" on the right side of the transmission (fig. 315). Leave the transmission in neutral and start the
engine. Accelerate the engine to full governed speed of
2200-rpm and note the pressure indicated on the
pressure gauge.
(b) If the converter pressure is 65-psi to
100-psi maximum, the converter is in normal operating
condition. With the engine idling at 500rpm, converter
pressure will be 15-psi to 60-psi.
(c) If the pressure is above 100-psi at
2200rpm, check for cause of excessive pump pressure;
enlarged metering orifice, restricted converter return
passages, or maladjustment of cooling circuit resistor
valve.
(d) If the pressure is below 65-psi,
check for low oil level, restricted intake screen, faulty
3-21
paragraph (3) (d) above for causes. Table 3-2 indicates
the normal pressures at various rpm’s.
Engine
RPM
500
1000
1500
2000
NOTE
The pressures are to be obtained with
oil at 200° F. and at indicated engine
speeds. (All pressures in pounds per
square inch ).
Table 3-2. Clutch Oil Pressures (Free Running)
Main Line
Converter
Forward
Pump press
in.
clutch
minimum
maximum
minimum
maximu
minimum
maximum
m
18
30
15
25
1
2
..
..
..
..
..
..
..
..
..
..
..
..
90
115
65
80
70
87
(5) Cooler circuit. To check cooler circuit,
circuit must be open and relief valve setting must be
within the proper range of 65- to 100-psi.
(a) The cooler hoses must not be
crimped, crushed, bent, or deteriorated in any way which
might restrict the flow of oil.
(b) The cooler in the bottom of the
radiator must not be restricted in the flow of oil nor
should the passages in the radiator be coated with lime
deposits which will restrict transfer of heat from
transmission oil to cooling system.
(c) Disconnect the cooler return hose at the
return port on the left side of the converter housing
adapter. Plug the cooler return port. Install a 200psi
pressure gauge in the cooler hose. With the clutch
engaged and the oil pump temperature at 120° to 170°F.,
run the engine at governed speed. The relief valve
which protects the cooling oil circuit is preset and opens
at 65-psi to 100-psi. It should open near 100-psi, and
never under 65-psi. If pressure is below 65-psi or above
100-psi replace spring and copper washer.
(6) Overheating. When a transmission has
overheated and become sludged, the following
procedure for cleaning is recommended:
(a) Drain two quarts of oil from the
transmission.
(b) Add two quarts of OE-10 oil and
operate unit for 50 hours before drain and flush.
(c) At 50 hours, drain the transmission
oil while the transmission is warm.
(d) Fill transmission with OE-10 oil and
operate 10 minutes at high idle. DO NOT STALL.
Operate in both directions and drain.
(e) Clean oil screen with a small brush
or an air hose.
(f) Flush with one gallon of OE-10 oil. Make
certain all internal parts are thoroughly drained by
removing the 1/8" pipe plug from the converter and
turning the engine by hand until the opening is straight
down. This will allow the fluid to drain from the converter
and out through the hole in the bottom of the flywheel
housing.
Reverse
clutch
minimum maximum
15
..
..
70
27
..
..
87
(g) Replace the drain plugs and fill
transmission with OE-10.
c. Removal.
(1) Remove floor plates, seat deck (para 2-9),
front grille and seat support, battery case and battery and
one corner post (TM 10-3930-618-20).
(2) Drain oil from transmission by removing
drain plug at rear of sump.
(3) Disconnect cooler lines at the right and left
sides of the transmission housing.
(4) Remove all
control
linkage
from
transmission (para 2-9).
(5) Remove drive shaft from universal joints
(para 5-21).
(6) Attach sling and hoist to transmission case
(fig. 3-17). Remove 12 capscrews and lockwashers
holding converter housing to flywheel housing.
Figure 3-17. Transmission removal and installation.
3-22
(7) Carefully work transmission assembly
forward until transmission case clears torque converter,
and remove from truck.
NOTE
Jacking screws may be used in the
two tapped holes in the transmission
case to aid in removal.
(8) To remove torque converter from engine
flywheel, refer to paragraph 2-9 c.
(9) To remove pump from turbine shaft, mark
pump and converter housing to insure proper
reinstallation. Remove capscrews holding pump and
collector ring to converter housing.
(fig.
3-18).
Figure 3-18. Pump removal and installation.
d. Disassembly.
(1) Refer to figure 3-19 and disassemble the
torque converter from the flywheel drive plate.
1 Bolt
2 Plate
3 Capscrew
4 Lockwasher
5 Converter
6 Pump assembly
7 Bolt
8 Lockwasher
9 Preformed packing
10 Capscrew
11 Oil seal
12 Shaft
13 Housing
14 Bolt
15 Lockwasher
16 Plate
17 Housing
18 Bolt
19 Lockwasher
20 Support
21 Preformed packing
22 Preformed packing
23 Preformed packing
24 Snap ring
25 Seal
26 Seal
27 Plug
28 Plug
29 Seal
30 Spring
31 Ball
Figure 3-19. Torque converter and pump assembly, disassembly, and reassembly.
3-23
(2) Remove the bolts (7) and lockwasher (8)
and remove pump. Remove the preformed packing (9)
from the pump. Remove the capscrews (10) and
separate the oil seal (11) from the housing (13).
Remove the pump shaft (12).
(3) Remove the bolts (14) and lockwashers
(15) and remove the plate (16) from the converter
housing (17).
(4) Remove the bolts (18) and lockwashers
(19) and remove the support (20).
Remove the
preformed packings (21, 22 and 23), snap ring (24) and
seals (25 and 26).
(5) Remove the plugs (27) from the plate.
Remove the plug (28) and (29) spring (30) and ball (31).
e. Inspection, Cleaning and Repair.
(1) Inspect the dirt or sludge for abrasive
matter (metal fillings).
If it has metal particles,
investigate possible source of wear, or failure that
caused accumulation. Replace defective part or parts,
then use extreme care in cleaning the components.
CAUTION
Parts cleaned by steam must be
protected with an even coating of OE 10
oil applied immediately after drying with
filtered compressed air.
Never dry
bearings with compressed air.
NOTE
All metallic parts, except bearings,
may be cleaned in dry cleaning
solvent (Fed. P-D-680), in diesel fuel
(Fed VV-F-800), or may be cleaned by
the steam l cleaning method. Wash
bearings.
only in dry cleaning
solvent (Fed P-D-680). When grease
has hardened in used bearings,
always soak them in the solvent for
several hours, for ease in cleaning.
CAUTION
Protect all parts from contamination after
cleaning, and before inspection or
reassembly, by an even coating of the oil
to be used in the converter (LO 5-3930618-12). Keep oiled parts covered with
clean paper or cloth, and handle
carefully during inspection to avoid
leaving finger prints on machined
surfaces.
(2) Inspect pump and if gears, bushings, or
housing show wear, pump will have to be replaced.
(3) Check face of pump collector ring for
score marks caused by tangs of converter. If marks are
present, it indicates converter is not properly shimmed at
flywheel. (para 2-9d).
f. Reassembly.
(1) Install new preformed packings and oil
seals.
(2) Lubricate all parts with light oil.
(3) Install pump on collector ring. Make sure
holes are properly aligned.
(4) Install pump assembly, on converter
housing adapter, using new gasket.
Section VI. REPAIR OF TRANSMISSION
work area, and proceed as follows for complete
disassembly (refer to fig. 3-20 for detail).
3-16. Transmission Assembly
a. Disassembly.
(1) Place transmission assembly on a suitable
3-24
Figure 3-20. Transmission.
(2) Pump. To remove the pump assembly,
refer to paragraph 3-15 c.
drum.
Lay
(3) Converter housing and
transmission on gear case (fig.
3-21).
Remove
capscrews which mount converter housing adapter to
gear case. Attach chain to housing and remove housing
and disc drum assembly as a unit, taking care not to
damage seal rings in collector ring on gear case.
Figure 3-21. Housing and drum assembly removal and
installation.
3-25
arbor press.
(a) Place drum and disc assembly in
Apply pressure on turbine shaft until
cylinder is depressed enough to remove large snapring
(1, fig. 3-22).
1 Snap ring
2 Capscrew
3 Lockwasher
4 Cylinder
5 Seal ring
6 Seal ring
7 Needle bearing
8 Turbine shaft
9 Piston
10 Disc
11 Spring
12 Pin
13 Snap ring
14 Cylinder
15 Seal ring
16 Seal ring
17 Piston
18 Disc
19 Drum
Figure 3-22. Forward reverse disc assembly.
(b) Remove the capscrews (2) and
lockwashers (3) and remove the cylinder (4) from the
turbine shaft (8). Remove seal rings (5 and 6). Remove
the needle bearing (7) from the turbine shaft (8).
(c) Remove the piston (9), forward drive
disc 10), spring (11) and pins (12) from the drum.
(d) Remove snap ring (13), cylinder (14), seal
rings (15 and 16), piston (17) and reverse disc (18) from
drum (19).
(4) Transmission control valve.
(a) Remove
bolts
and
washers
attaching transmission control valve to transmission
case.
(b) Clean valve exterior with cleaning
compound, solvent (Spec. P-S-661). Dry thoroughly
with compressed air.
(c) Remove valve cover bolts (1, fig. 323) and lockwashers (2), valve cover (29), and gasket
(28). Discard gasket.
3-26
1 Bolt
2 Lockwasher
3 Bolt
4 Lockwasher
5 Selector stop
6 Selector spring
7 Selector ball
8 Selector bushing
9 Selector spool
10 Oil seal
11 Retaining screw
12 Gasket
13 Drum spring
14 Drum spool
15 Inching spool spring
16 Inching spool
17 Inching plunger spring
18 Inching plunger
19 Oil seal
20 Regulator spring
Figure 3-23. Transmission control valve.
3-27
21 Regulator spool
22 Gasket
23 Plunger stop
24 Body
25 Inching stop
26 Gasket
27 Separator plate
28 Gasket
29 Cover
(d) Remove separator plate bolts (3)
and lockwashers (4), separate plate (27), and gasket
(26), and valve body gasket (22). Discard gaskets.
(e) Remove selector valve ball (7),
spring (6), and bushing (8).
(f) Remove selector valve stop (5), and
slide selector spool (9) from valve body (24).
(g) Remove and discard oil seal (10).
(h) Remove inching valve plunger stop
(23) and slide plunger (18) and spring (17) from valve
body (24).
(i) Remove and discard oil seal /(19).
(j) Remove inching valve spool stop
(25), spool (16), and spring (15) from inside spool.
(k) Slowly remove regulator and dump
valve retaining screws (11) and gaskets (12). Discard
gaskets.
(I) Remove regulator valve spring (201
and spool (21 ), and dump valve, spring (13) and spool
(14).
(5) Forward gear and shaft.
(a) Remove bolts (15, fig. 3-24) and
lockwasher (16) holding bearing retainer (14) and gasket
(13) to case and remove retainer with gasket Discard
gasket.
(b) Remove bearing retaining ring (17),
depress retaining ring on bearing, and slide bearing (12)
from forward shaft (11).
through
valve
control
(c) Reach
opening, remove forward gear retaining rings (1U).
(d) Using a rawhide hammer and
holding forward gear (9) in place, tap forward shaft (11)
out through bearing retainer opening. Remove
Figure 3-24. Single speed transmission disassembly (sheet 1 of 2)
3-28
Key to figure 3-24
1 Packing
2 Collector ring
3 Needle bearings
4 Reverse shaft
5 Retaining ring
6 Ball bearing
7 Lockwasher
8 Bolt
9 Forward gear
10 Retaining ring
11 Forward shaft
12 Bearing
13 Gasket
14 Retainer
15 Bolt
16 lockwasher
17 Retaining ring
18 Idling gear
19 Needle bearings
20 Idler shaft
21 Gasket
22 Pin
(6) Remove reverse gear and shaft.
Match mark collector ring (2) and
(a)
remove collector ring attaching lockwashers (7) and bolts
(8) and collector ring.
(b) Remove packings (1) from collector
ring.
(c) Remove needle bearings (3 and 44)
from reverse shaft (4).
(d) Remove retaining ring (10) and
reverse
gear (43) from reverse shaft (4) (see fig. 325).
(e) Tap shaft (4, fig. 3-24) out disc and
drum
assembly side of transmission and remove
bearing retaining ring (5).
23 Retainer
24 Bolt
25 Lockwasher
26 Plug
27 Ball bearing
28 Output gear
29 Output shaft
30 Gasket
31 Retainer
32 Lockwasher
33 Bolt
34 Flange
35 Oil seal
36 Gage
37 Case
38 Drain plug
39 Screen
40 Spring
41 Plug
42 Gasket
43 Reverse gear
44 Needle bearing
Figure 3-24. Single speed transmission disassembly
(sheet 2 of 2).
3-29
Figure 3-25. Reverse gear and shaft, removal and installation.
(f) Remove hearing (6) with retaining
(b) Remove retainer (31) by removing
attaching bolts (33) and lockwashers (32). Discard
gasket (30).
(c) While holding output gear (28) in
gear box, remove output shaft (29) (fig. 3-27).
ring.
(7) Idler gear shaft.
(a) Remove retainer (23) by removing
attaching bolts (24) and lockwashers (25). Discard
gasket (21).
(b) Mark position of pin (22) holding
shaft in retainer (23) to insure proper assembly and
remove pin.
(c) Remove idler shaft (20) and idler
gear assembly (fig. 3-26).
NOTE
Idler gear assembly consists of two
needle bearings (19, fig. 3-24) and a
gear (18).
Figure 3-27. Output gear and shaft, removal and
installation.
(d) Remove gear (28, fig. 3-24) and
both ball bearings (27).
(e) Remove expansion plug (26).
(9) Remove plug (41, fig. 3-24), spring (40),
and screen (39), from bottom portion of transmission
case (37).
b. Cleaning, Inspection, and Repair. Assure that
none of the dirt or sludge contains abrasive matter (metal
filings). If it has metal particles investigate possible
source of wear, or failure that caused accumulation.
Replace defective part or parts, then use extreme care in
cleaning the components.
Figure 3-26. Idler gear shaft, removal and installation.
(8) Output gear and shaft.
(a) Remove output flange (34) and oil
seal (35).
3-30
When teeth are worn out of shape, or gear is cracked,
replace the gear.
(h) rings for spring tension, wear, nick,
or bur. Replace a defective ring.
(i) Springs for discoloration from heat,
permanent set, or wear. Replace a defective spring.
(j) Mounting hardware for burs or other
damage. Chase a burred external thread with proper
size die. Chase a burred internal thread with proper size
tap. Replace defective mounting hardware.
(k) for burs, twist, or chip, and wear that
affects tightness of fit. When bur or chip cannot be
removed with a soft stone, or wear is excessive, replace
the defective part.
(l) Inspect sump screen for clogged or
damaged screen.
NOTE
Thoroughly clean the intake screen
and spring. In addition to soaking
and washing, air streams should be
directed from the outside toward the
inside to remove material clogged in
the screen and spring.
(m) Inspect drive discs, pistons and
drum for wear or damage, Should any of these parts
show evidence of excessive wear or scored marks, they
should be replaced.
(n) Inspect control valve plungers and
spools for score marks - clean up with crocus cloth or
replace as required. Check spring for damage. Replace
oil seals, seal rings and gaskets.
c. Reassembly. To reassemble the transmission,
reverse the disassembly procedure. During reassembly,
note the following:
valve
assembly.
Reverse
(1) Control
disassembly procedure making sure plungers and spools
operate freely and retainer at both forward - reverse
plunger and inching valve plunger are installed with
angled edges facing back of valve body.
(2) Drum and disc assembly.
(a) Install reverse drive disc, piston, and
cylinder. Make sure cylinder and piston does not bind in
drum or on dowel pins. Install large snapring holding
cylinder in place.
(b) Turn drum over and install springs,
drive disc, piston and cylinder.
(c) Place assembly in arbor press.
Apply pressure on turbine shaft, making sure cylinder
does not bind in drum or on dowel pins. Install large
snapring holding cylinder in place and release pressure
in arbor press.
(d) should be exercised when installing
converter housing on turbine shaft of disc drum, so that
misalignment does not occur during assembly. Make
sure snapring holding converter housing .to turbine shaft
is properly seated.
CAUTION
Parts cleaned by steam must be
protected with an even coating of OE
10 oil applied immediately after
drying with filtered compressed air.
Never dry bearings with compressed
air.
NOTE
All metallic parts, except bearings,
may be cleaned in dry cleaning
solvent (Fed P-D-680), in diesel fuel
(Fed VV-F-8001, or may be cleaned by
the steam cleaning method. Wash
bearings only in dry cleaning solvent
(Fed P-D-6801. When grease has
hardened in used bearings. always
soak them in the solvent for several
hours, for ease in cleaning.
CAUTION
Protect all parts from contamination
after cleaning, and before inspection
or reassembly, by an even coating of
the oil to be used in the converter (LO
53930-618-12).
Keep oiled parts
covered with clean paper or cloth,
and
handle
carefully
during
inspection
to
avoid
leaving
fingerprints on machined surfaces.
(1) Clean all metallic parts carefully, paying
particular attention to oil passages by running a clean
wire back and forth through the passage, blow dry with
filtered compressed air, then coat all parts with an even
coating of oil. (See caution above).
(2) Inspect all parts for the following:
(a) Bores for wear, burs, scratches, or
grooves. Remove minor burs and scratches with crocus
cloth.
Replace parts that are deeply grooved or
scratched.
(b) Mounting faces for nicks, burs, or
scratches. Remove such defects with crocus cloth or a
soft stone.
(c) Threaded openings for damaged
threads. Chase a damaged thread with correct size tap.
(d) Castings for cracks or other
damage. Replace a cracked casting.
(e) Sleeve bearings and thrust washers
for scoring, sharp edges, roundness, burs, or
discoloration from overheating. Remove scoring with
crocus cloth. Burs and sharp edges may be removed
with a scraper.
Excessive wear, out-of-round, or
overheated items require replacement.
(f) seals and gaskets for wear, cuts,
and deterioration. Replace defective seals and rings.
Replace all composition gaskets.
(g) teeth for wear, nicks, or burs. Gear
thrust face for scores, nicks, or burs, and gears for
cracks, or breaks. When burs, scores or nicks cannot
be removed with a soft stone, replace the defective gear.
3-31
(3) Transmission gear train.
(a) Make sure spring is in place when
installing oil strainer in housing.
(b) sure output shaft is installed with
internal splines to outside of gear case.
(c) sure machined reliefs in idler shaft
cap are positioned down so that oil in cap will drain in
housing.
(d) As gears and bearings are being
installed, coat with lubricant and make sure they rotate
freely.
(e) When installing forward and reverse
drive disc shafts and gears, check to make sure
snaprings holding gears on shaft are properly installed
and seated.
(4) Converter housing and disc drum and
transmission housing. When installing converter housing
and disc drum (as a unit) into the transmission housing,
care should be exercised so as not to damage collector
rings fitting into disc drum, as damage to these rings will
cause the reverse piston and disc to be inoperative.
(5) Control valve assembly and transmission.
(a) new gaskets when replacing control
valve.
(b) capscrews evenly to 5-to 10-foot
pounds.
(6) Pump assembly and turbine shaft.
(a) When installing pump assembly on
turbine shaft, collector ring aligning marks must match
marks made in disassembly.
(b) Make sure rings rotate free on
collector ring and that rings are properly hooked together
at ring ends.
(c) Use new gaskets and make sure
mounting holes are properly aligned.
d. Installation.
NOTE
For
proper
reinstallation
of
transmission and torque converter,
refer to Converter Replacement (para
2-9d ). After correct alignment has
been
obtained,
the
following
procedure is recommended:
(1) Mark one mounting strap and flywheel for
identification and remove converter from flywheel being
careful not to damage or loose shims, if any, on
converter pilot.
(2) Position converter in pump at back of
transmission, making sure converter hub tangs properly
engage pump driven gear.
(3) Reinstall transmission on flywheel bell
housing as follows:
(a) Mount converter to flywheel by
installing capscrews and lockwashers through’ inspection
plate in flywheel bell housing.
(b) After converter has been securely
installed, rotate until filler hole appears and add one
quart of oil.
(c) After assembly has been installed in
truck, add 10 quarts of oil to transmission. See LO 103930-618-12 for lubrication requirement.
(d) Test
the
operation
of
the
transmission, use the procedure outlined in paragraph
3-15b.
3-17. Inching Pedal and Brake Pedal
a. Description. The inching pedal is installed on the
same shaft as the brake pedal, and cannot be removed
without removing the brake pedal. The inching pedal
controls operation of the inching valve, which is part of
the transmission control valve assembly and also
actuates the brakes to provide simultaneous
transmission disengagement and position braking.
b. Removal.
(1) Remove floor plates (TM 10-3930-61820).
(2) Disconnect master cylinder clevis pin (fig.
3-28, sheet 1 of 2) from the brake pedal, and the inching
pedal pivot shaft (8, fig. 3-28, sheet 2 of 2).
(3) Remove pedal springs (15) and brake
pedal bumper (14).
(4) Remove pin (6) through brake pedal (4)
and shaft (8).
(5) Remove shaft support bearing (9) on
steering shaft bracket.
(6) Pull shaft through bracket far enough to
slide brake pedal off shaft.
(7) Push shaft back through bracket, but drop
the free end below the support bearing on the right frame
member until shaft drops free.
(8) Slide inching pedal (9, fig. 3-29) off shaft.
c. Cleaning and Inspection.
(1) Clean all parts with cleaning solvent and
dry with compressed air.
(2) Inspect bushings (16) and shaft for
excessive wear.
(3) Inspect treadle pad (8) for cracks,
deformation, or other damage.
(4) Replace damaged or worn parts.
d. Installation.
(1) Reverse removal procedures.
(2) Do not attempt to drive roll pin (6, fig. 328) home until holes in brake pedal (4) and shaft (8) are
properly aligned.
e. Adjustment of Inching Pedal Linkage. Because
the inching pedal (9, fig. 3-29) stroke is limited by the
inching valve stroke, the adjustment between-the pedal
adjusting screw (14) and the plunger rod (4) must be set
so the pedal (9) is fully released when the inching valve
bottoms. Adjust as follows:
(1) Remove the floor plate.
(2) Depress the inching pedal down to the toe
plate. The inching valve plunger rod (4) should move M6
the end of its stroke.
(3) Slowly release the pedal and observe the
action. When the pedal is fully released and resting on
the stop, the inching valve plunger rod (4) should just
bottom.
3-32
CAUTION
Do not attempt to stop the pedal
travel with the valve plunger rod
alone.
(4) If the valve plunger rod (4) bottoms before
the pedal (9) is fully released, and resting on its stop,
turn the pedal stop adjusting screw (14) in or out until
correct adjustment is obtained.
f. Service Brake Pedal Adjustment. The ideal
pedal free play is h inch. Too little free travel will prevent
the master cylinder piston from returning to full OFF
position and the brakes will begin to drag after several
applications. Excessive free travel will reduce the usable
stroke of the master cylinder.
Refer to figure 3-28 and adjust as follows:
(1) Remove the floor plates.
(2) Slowly depress the brake pedal and check
for 1/2 inch free travel. Also observe push rod action.
(3) To obtain the proper free travel, loosen the
locknut on the clevis and then turn the adjusting nut.
(4) Tighten the locknut and reinstall the floor
plates.
1 Nut
2 Lockwasher
3 Washer
4 Pedal
5 Pedal pad
6 Pin
7 Washer
8 Pivot shaft
9 Support bearing
10 Loekwasher
11 Capicrew
12 Capscrew
13 Bracket
14 Bumper
15 Spring
16 Adjusting screw
17 Clip
Figure 3-28. Brake pedal (sheet 2 of 2).
Figure 3-28. Brake pedal (sheet 1 of 2)
3-33
1 Nut
2 Lockwasher
3 Ball joint
4 Rod
5 Washer
6 Fitting
7 Spring
8 Pad
Figure 3-29. Inching pedal
9 Pedal
10 Lockwasher
11 Nut
12 Bellcrank
13 Pin
14 Screw
15 Nut
16 Bushing
Section VII. REPAIR OF ENGINE
(g) Thermostat
(2) Remove speed limiting governor (para 3-
3-18. General
This section describes direct and general support
maintenance of the Allis-Chalmers engine Model
6MB230 used in the forklift truck. Internal repairs to the
engine, except valve grinding, will require its removal
from the truck.
9).
(3) Remove oil pan (para 3-12).
(4) Remove oil pump (para 3-13).
3-20. Cylinder Head, Block, and Sleeves
a. Cylinder Head.
(1) Description. The cylinder head is a onepiece, alloy iron, casting which is attached to the top of
the cylinder block by special capscrews.
Cored
passages in cylinder head provide for intake of fuel-air
mixture and expulsion of exhaust gage Cored passages
are provided for circulation of coolant.
To seal
compression, a head gasket and fire rings are installed
between cylinder head and block. Located in the cylinder
head above each cylinder is an intake valve, an exhaust
valve, replaceable valve seat inserts, two valve guides, a
spark plug, and two rocker arms. The valves are
operated by rocker
3-19. Engine Removal and Disassembly
a. Removal. Remove the power plant from the
truck and separate the transmission, torque converter
and hydraulic pump from the engine (para 2-9 and 2-10}.
b. Disassembly.
(1) Refer to TM 10-3930-618-20 and
remove the following accessories and components:
(a) Fan and water pump.
(b) Alternator and starter motor.
(c) Carburetor
(d) Fuel pump.
(e) Manifold.
(f) Distributor
3-34
(b) Operations requiring head removal.
1. Grinding, reseating or replacement
of valves (para 3-23).
2. Replacement of valve guides (para
3-23).
3. Replacement of exhaust "salve
seat inserts (para 3-23).
(3) Removal of cylinder head.
(a) Remove side panels, seat deck and
supports, battery, and battery tray (TM 10-3930-618-20).
(b) Drain radiator and block.
(c) Remove vent hose from rocker arm
cover.
(d) Remove nut (1, fig.
3-30) and
washers
(2) from stud (15). Then remove cover (3)
and rocker arm assembly (para 3-23).
arms. Valve guides, pressed into the cylinder head, hold
valves in accurate alignment with valve seats. Top of
cylinder head, with the valve and rocker arm assembly, is
inclosed by a cover.
(2) Cylinder head service. Service on some
parts contained in the head can be accomplished with
the head installed on engine. Other service operations
require head removal.
(a) Operations not requiring head removal.
1. Adjustment of valve clearance (TM
10-3930-618-20).
2. Replacement of rocker arms,
rocker arm shafts, or springs (para 3-23).
3. Replace of push rods (para 3-23).
4. Replacement of valve springs (para
3-23).
5. Removal of spark plugs (TM 103930-618-20).
3-35
1 Nut
2 Washer
3 Cover
4 Gasket
5 Nut
6 Washer
7 Stud
8 Cover
9 Gasket
10 Washer
11 Capscrew
12 Stud
13 Stud
14 Valve guide
15 Stud
16 Capscrew
17 Washer
18 Pipe plug
19 Cylinder head assembly
20 Expansion plug
Figure 3-30. Cylinder head and valves.
3-36
21 Exhaust valve insert
22 Intake valve insert
23 Fire ring
24 Head Gasket
25 Exhaust valve
26 Intake valve
27 Salve spring
28 Valve retainer
29 Lock
30 Rotor cap
(e) Remove spark plug cables.
(f) Remove radiator connections to
engine and transmission (TM 10-3930-618-20).
(g) Disconnect rocker arm oil feed line
from head and move out of way.
(h) Remove cylinder head capscrews
(11 and 16, fig. 3-30), nuts (5) and washers (6, 10, and
17). Lift cylinder head assembly (19) from block with a
sling. Discard fire rings (23) and head gasket (24).
(4) Inspection of cylinder head.
(a) Clean cylinder head, removing all
carbon deposits, and inspect for wear or other damage.
(b) Before removing valves (para 3-23)
check them for seating.
(c) Replace defective parts.
NOTE
If cylinder head is to be replaced,
parts from the defective head must
be thoroughly inspected before
installing them in a new head. For
inspection procedures for valves and
rocker arm assembly (para 3-23) and
for spark plugs, see TM 10-3930-61820.
(5) Installation of cylinder head.
(a) Thoroughly clean the top deck of the
cylinder block and the underside of the cylinder head.
(b) Do not use any sealer or gasket
dope on any part of the cylinder head gasket assembly.
(c) Install guide studs in holes (19 and
20. fig. 3-31).
3. Retighten capscrews in numerical
sequence to full recommended torque.
4. Run
engine
until
coolant
temperature reaches minimum of 160°F, (approx. 1
hour), then retorque capscrews to the full recommended
torque in the specified numerical sequence.
(g) Reset the valve tappet clearance.
b. Cylinder Block and Cylinder Sleeves.
(1) Description. The cylinder block is a onepiece iron casting. Integral transverse members provide
rigidity and strength, assuring accurate alignment of
crankshaft bearings and cylinder sleeves. Block is bored
to receive removable cylinder sleeves which are
completely surrounded by full-length water jackets for
maximum cooling.
The main oil gallery extends
lengthwise through the cylinder block, below and parallel
to the camshaft. Oil passages direct oil from main oil
gallery to main bearings. A horizontal oil passage leads
to the outside of the cylinder block and is connected by
tubing to lubricate rocker arm assembly. The removable
cylinder sleeves are made of alloy cast iron. Two
silicone rubber packing rings, fitted into grooves in lower
bore of cylinder block, prevent water leakage into
crankcase. Sleeve is seated at top by a flange which fits
into a machined recess in block. Cylinder head gasket
and fire rings are compressed between this flange and
cylinder head, holding sleeve in place.
(2) Removal of cylinder sleeve.
NOTE
When removing sleeves and pistons.
do not interchange parts.
If any
sleeves are to be reused, they should
be reinstalled in the same sleeve bore
from which the)y were removed.
Pistons must be reinstalled in the
same sleeves from which they were
removed.
If engine has already been removed from truck,
disregard (a) below.
(a) Remove engine from truck (para 29).
(b) Remove cylinder head assembly
(para a above).
(c) Remove pistons and connecting
rods (para 3-22).
(d) Rotate crankshaft to gain access for
installation of cylinder sleeve puller.
(3) Cylinder sleeve tool. Install puller tool to
remove cylinder sleeve from top of cylinder block.
NOTE
Figure 3-31. Sequence for cylinder head Capscrew
tightening.
(d) Position the head gasket on the
cylinder block guide studs. Position the fire rings inside
the cylinder bores of the gasket and be sure no
overlapping of the fire rings by the gasket occurs.
(e) Carefully install the head, being sure
not to displace the positioned fire rings. Head is to be
located by the guide studs. Install capscrews in all
locations except those occupied by guide studs.
(f) Torque the capscrews to a final
torque of 110 ft-lbs. in the following manner (fig. 3-31).
1. Tighten capscrews in numerical
sequence to 1/2, final torque. Remove guide studs and
install lifting studs when reaching these locations.
2. Tighten capscrews in numerical
sequence to full recommended torque.
If sleeve puller is not available, sleeves
may be loosened by placing end of
hardwood block against bottom of sleeve
and striking block sharply with a
hammer. Be careful not to hit cylinder
block.
(4)
sleeves.
3-37
Cleaning and inspection of cylinder
(a)
Remove all carbon, dirt, and oil from
cylinder sleeves and machine recess bore in cylinder
block. Replace cylinder sleeves if scored or worn
beyond allowable limits of 0.008 inch. Slightly scuffed
cylinder sleeves, if not worn, may sometimes be made
usable by polishing or lapping to remove surface
irregularities.
(b)
Check cylinder sleeves for roundness by
means of a cylinder diameter checking gauge. Allowable
out-of-round when installed is 0.001 inch. Using an
inside micrometer, measure cylinder sleeve for taper and
wear. Inside diameter of new cylinder sleeve is 3.4379
inch to 3.4385 inch. Cylinder sleeve should be round to
within 0.001 inch, and have no more than 0.0007-inch
taper. Cylinder sleeves that are more that 0.001 inch
out- of-round or have more than 0.0007-inch taper when
installed, must be replaced.
These measurements
should be taken at several locations within the area of
piston ring travel.
(c) If cylinder sleeves are within
allowable wear limits and are to be used again, there
may be a slight ring travel ridge near top of the sleeve
which should be removed with a ridge reamer. Follow
the instructions of the manufacturer of the specific ridge
reamer.
(d) Refer to paragraph 3-22 for
instructions on the fitting of pistons in cylinder sleeves.
(5) Installation of cylinder sleeve.
(a) Thoroughly clean cylinder sleeve (2,
fig. 3-32) and the bore in cylinder blocks (3). Be sure
bottom surface of flange on cylinder sleeve and
counterbore in cylinder block are clean and free from
nicks or burs.
(b) Before installing silicone rubber seal
rings (1) insert sleeve (2) into bore to make certain
sleeve can be pushed down into place by hand pressure.
Withdraw sleeve from block. If sleeve cannot be
inserted in above manner, more cleaning is necessary or
sleeves are distorted.
(c) Install silicone rubber seal rings as
follows:
1. Thoroughly clean the cylinder
sleeves and wipe or blow them dry. Thoroughly clean
the sleeve bores and O-ring grooves in the cylinder
block. Check the sleeve flange counterbores in the
block to be sure the sleeve flange seats are true and
square with the upper and lower deck sleeve bores in the
block. Check the depth of the flange counterbores in the
block to be sure the specified sleeve protrusion above
the top deck of the block is maintained.
2. Install the dry silicone cylinder
sleeve packing rings in both grooves in the cylinder
block. 3. Brush a light coat of light engine lubricating oil
in the lower sleeve bores and on the sleeve rubbers in
the cylinder block and on the sleeve immediately prior to
installation of the sleeve in the cylinder block.
CAUTION
Use only a light engine lubricating oil
as a lubricant for the cylinder sleeve
packing
rings
when
installing
cylinder sleeves in a cylinder block.
(d) With silicone rubber seal rings installed,
install sleeve in position in cylinder block, being careful
not to cut or scratch seal rings. When sleeve is nearly in
place, apply pressure to opposite sides of sleeve with
hands and press into place with a sudden, quick
application of pressure. Be careful not to get dirt under
flange of sleeve, which would prevent it from properly
seating.
(e) With flange of cylinder sleeve firmly
seated in counterbore of cylinder block, top surface of
cylinder sleeve must be -0.002 inch to +0.002 inch above
top flat surface of the cylinder block. Hold a straightedge
across cylinder sleeve and use a feeler gauge to
measure standout of sleeve flange above block.
c. Cleaning and Inspection of Cylinder Block. The
cylinder block is the main structural part of the engine,
therefore, whenever engine is overhauled, thoroughly
inspect block for any damage which may render it unfit
for further use. Make inspection of block after all parts
have been removed and it has been thoroughly cleaned
with steam or cleaning solvent (Spec P-S-661) and dried
with compressed air. All oil passages in cylinder block
must be cleaned before assembling engine. Effective
cleaning of these passages can be accomplished only
with the use of high steam pressure with a solvent used
in the water to dissolve the sludge and foreign material
that has collected. Open all passages before flushing.
(1) Remove expansion plugs (4, fig. 3-32) at
front and rear of engine.
3-38
1 Packing ring
2 Sleeve
3 Block assembly
4 Expansion plug
5 Camshaft bearing, rear
6 Camshaft bearing, interm
7 Camshaft bearing, front
8 Dowel pin
9 Bearing cap, rear
10 Bearing cap, interm
11 Plug
12 Pipe plug
13 Bearing cap, center
14 Dowel pin
15 Lockwasher
16 Insert
17 Bearing cap, front
18 Pipe plug
19 Dowel pin
20 Stud
21 Pipe plug
22 Drain cock
23 Pipe plug
24 Gasket
25 Lockwasher
26 Capscrew
27 Oil pressure sender
28 Main bearing, rear
29 Main bearing, interm
30 Piston
31 Spring
32 Nut
33 Adjusting screw
34 Main bearing, center
35 Main bearing, front
36 Capscrew
Figure 3-32. Cylinder block.
3-39
jackets, apply high pressure steam and water through all
block openings. Turn block in various positions while
this is being done so that loose scale will be washed out.
After oil and water passages have been cleaned and
block has been inspected, install expansion plugs (4, fig.
3-32) and oil pressure relief valve (para 3-14). Oil gallery
plugs should be coated with a sealing compound and
installed flush with, or below the surface, so that they will
not interfere with fit of attached parts.
3-21. Crankshaft, Main Bearings, Gear, and Pulley
a. Description.
(1) Crankshaft.
The crankshaft is a
counterbalanced, heat-treated, steel drop forging drilled
for pressure lubrication to main and connecting rod
bearings. It is balanced both statically and dynamically
and is supported by seven main bearings. Crankshaft
end thrust is taken by thrust flanges on each side of
center main bearings.
Main bearings are
(2) Main bearings.
replaceable without machining. The front main bearing
is 1 1/16 inch long; the center main bearing is 1 7/8 inch
long, and the rear main bearing is 1 23/32 inch long. All
intermediate bearings have an inside diameter of 2.5007
inches to 2.5024 inches with bearing caps tightened to
specified torque (table 1-1). The main bearing caps are
attached to the cylinder block and line bored in position
to receive the bearing shells. Each bearing cap is
numbered and when removed should always be
reinstalled in respective position and corresponding to
the numbers stamped on the bottom of the cylinder
block. The upper halves of the main bearing shells are
seated in the lower part of the cylinder block. The lower
halves are held in place by the main bearing caps, each
of which is attached to the cylinder block by capscrews
and lockwashers. Each half of the bearing shell is
prevented from radial movement by a tang at the parting
line on one side of the bearing shell. A spring loaded,
lip-type oil seal is used at the rear of the crankshaft to
seal the crankcase oil from the flywheel compartment. A
spring loaded, lip-type oil seal, pressed into the timing
gear cover located on the front of the engine, is used to
seal the crankcase oil from leaking out at the front end of
the crankshaft.
(3) Gear and pulley. The gear and pulley are
installed, in that order, on the front end (threaded end) of
the crankshaft.
b. Removal. Inspection can be made of crankshaft
main bearings and journals by removing oil pan and
removing bearing caps one at a time. If crankshaft has
been damaged, removal of engine is necessary for shaft
replacement.
(1) Remove engine (para 2-9).
(2) Drain lubricating oil by removing drain plug
from bottom of oil pan.
(3) Remove transmission (para 3-16).
(4) Remove starter motor (TM 10-3930-61820).
(5) Remove flywheel and flywheel housing
(para 3-26).
(6) Remove crankshaft pulley as follows:
(a) Remove locknut (1, fig. 3-33).
(b) Using appropriate puller, remove
pulley (2).
(c) Remove key (6).
(7) Remove oil pan (para 3-12).
(8) Remove timing gear cover from front plate
(para 3-25).
(9) Remove lubricating oil pump (para 3-13).
(10) Remove connecting rod bearing caps and
bearing shells (para 3-22).
(11) Remove main bearing caps and bearing
shells as follows:
(a) Remove capscrews (36, fig. 3-32)
and lockwashers (15).
(b) Remove main bearing caps (9, 10,
13, and 17) and bearing shells (28, 29, 34, and 35).
(12) Remove crankshaft (fig. 3-34).
(13) Use gear puller and remove crankshaft
timing drive gear (3, fig. 3-33) and key (5).
c. Cleaning, Inspection, and Repair.
(1) Clean all parts in cleaning solvent (Spec
P-S-661) and dry with compressed air.
(2) Be sure to clean out the crankshaft oil
passages.
(3) Inspect crankshaft journals for scoring,
chipping, cracking, signs of overheating, or other
damage. If crankshaft has been overheated (usually
indicated by discolored or blue bearing journal surfaces),
is scored, or excessively worn, then reconditioning or
replacement will be necessary.
(4) Recheck crankshaft journals for fine
cracks if signs of overheating are observed.
(5) Measure crankshaft main bearing and
connecting rod journals at several points on their
diameter to check for out-of-roundness. The specified
diameter of the main bearing journals is 2.4984 inches to
2.4994 inches; the specified diameter of the connecting
rod journals is 2.1214 inches to 2.1224 inches.
(6) All main and connecting rod bearings
surfaces of the crankshaft are hardened to a depth of
0.070 inch.
d. Installation. Install crankshaft in reverse order of
procedure of b above, except (1) Inset key (15, fig. 3-33 into shaft.
3-40
(2) Heat crankshaft timing drive gear (3) in
boiling oil for at least 15 minutes to expand gear ID.
(3)
Pick up gear with tongs or pliers and
slide onto crankshaft. Aline “C” marks on crankshaft
and camshaft gears and mesh gears. It may be
necessary to tap gear with a wooden block and hammer
to seat it over key and against crankshaft shoulder.
1 Locknut
2 Pulley
3 Gear
4 Crankshaft
5 Key, gear
6 Key, pulley
Figure 3-33. crankshaft gear and pulley.
grooves in pin boss of piston. Pins are full-floating, but
normal movement is between pin and bushing in the
connecting rod.
(2) Connecting rods. Each connecting rod,
made of drop-forged, heat-treated steel, is forged to an
"I" section with closed hub at upper end and integral cap
at lower end and is dynamically and electronically
balanced. Connecting rod bearings are replaceable
without machining.
Each half of bearing shell is
prevented from radial movement by a tang at parting line
on one side of bearing shell. Bearing shells are held in
place by a cap which is attached to the connecting rod
with two special capscrews and castellated nuts. Upper
end of connecting rod contains a bushing which is
pressure lubricated.
b. Removal. Connecting rods and pistons may be
replaced without removing engine from truck. (If engine
has already been removed from truck, disregard (1), (2),
and (3) below).
(1) Remove cylinder head (para 3-20).
(2) Remove steering axle assembly (para 214).
Figure 3-34. Removing crankshaft.
3-22. Pistons and Connecting Rods
a. Description.
(1) Pistons.
The
precision-machined,
balanced, cast aluminum alloy, cam ground, and tipplated pistons are fitted with two compression and two oil
control rings, all located above piston pin. Behind oil
control ring, holes drilled through piston allow excess oil
in groove to return to crankcase. Piston pins are fullfloating type held in piston by two retainer rings fitted into
3-41
(3) Drain oil from crankcase and remove oil
pan (para 3-12).
(4) If cylinder sleeves (2, fig. 3-32) are worn
so there is a ridge at the upper end of ring travel, remove
ridge with a ridge reamer before piston is removed. This
prevents damage to rings during removal and
installation.
(5) Remove nuts (11, fig. 3-35) and bearing
cap from each connecting rod (8) in turn and push piston
and connecting rod assembly out through top of cylinder
block. Reassemble bearing caps on their respective
connecting rods as they are removed.
(6) Inspect, disassemble, and reassemble
pistons and connecting rods as required.
(7) Inspect crankshaft 14, fig. 3-33) bearing
journals at connecting rod throws for scoring, checking,
or signs of overheating. If any of these conditions exist,
crankshaft will require reconditioning or replacing.
c. Disassembly.
(1) Using suitable tool. remove piston pin
retainer ring (5, fig. 3-35 ) at each end of piston pin (6).
(2) To avoid breaking piston rings, the use of
a ring remover and installer is recommended. Care must
be taken not to over-stress piston rings by spreading
ends more than is necessary to remove them from
piston. Before removing rings, inspect for wear and side
clearance in grooves.
However, removal will be
necessary in order to clean carbon from grooves.
(3) Using a driving tool, drive piston pin (6)
from piston. Use a wooden block or brass drift as a
driver. In some instances it may not be necessary to
drive piston pin from piston.
Specified clearance
between piston and pin at room temperature is 0.0001
inch to 0.0005 inch loose.
d. Piston and Piston Ring Inspection.
(1) As gummy deposits are not always
removed from piston walls and ring grooves with fuel,
these parts may be cleaned with Cleaning Solvent (Spec
P-S-661) and then blown off with dry compressed air.
After cleaning, piston skirt, piston rings, and ring grooves
should be thoroughly inspected.
CAUTION
Some types of solvents contain
chemicals injurious to aluminum
alloy. Do not use a cleaning agent
containing such chemicals.
(2) Piston skirt should be carefully inspected
for score marks or other indications of improper piston
clearance. Any scored pistons should be replaced.
(3) Inspect inside of piston for cracks, any of
which make it unfit for further use. Make certain that
drilled holes in piston walls are open and clean.
(4) Check piston for wear by inserting it into
cylinder sleeve and measuring clearance between piston
and sleeve. Maximum tolerance is from 0.0006 inch
tight to 0.002 inch loose, measured at bottom of piston
skirt and at right angles to piston pin.
1 Top ring
2 Second ring
3 Third and fourth ring
4 Piston
5 Pin retainer
6 Piston pin
7 Bushing
8 Connecting rod
9 Bolt
10 Rod bearing
11 Nut
Figure 3-35. Piston and connecting rod.
3-42
between aligner face and skirt of piston. If this space is
not equal distance, rod is twisted out of line.
NOTE
Ring lands at top of piston are
smaller than skirt: therefore, check
alignment of rod along full length of
skirt only.
(3) Twist rod with bending bar until space
between aligner face and piston skirt is even.
(4) Check for twist in the opposite diagonal
line to piston rod (piston head pointing up). Observe
space between aligner face and piston skirt. If space is
uneven, twist rod with bending bar until true alignment is
obtained.
(5) Check for bent rod by moving piston into
parallel position with connecting rod and observe space
between aligner face and piston skirt. If space is not
even, straighten rod carefully with bending bar.
g. Fitting Pistons to Cylinder Sleeves.
CAUTION
Measurement of pistons and cylinder
sleeves (2, fig. 3-32), and running
clearances between them should be
taken at room temperatures. Pistons
are cam ground and can be from
0.0006 inch tight to 0.002 inch loose
when fitted to their respective
cylinder sleeves before piston rings
are installed. Insufficient clearance
will result in premature failure of
these parts.
(1) Measure cylinder sleeves (para 3-20).
(2) Measure pistons (para d above).
NOTE
Pistons and cylinder sleeves are
available in standard size. 0.020 inch,
and 0.040 inch oversize.
h. Fitting Piston Rings.
(1) Gap between ends of piston rings should
be measured before rings are installed on piston. Select
rings to be installed on each piston, oil and insert them
one at a time into cylinder sleeve in which they are to
operate. Use a piston to push ring squarely into cylinder
sleeve so that it is parallel with top of cylinder block.
(2) Push ring far enough down in bore of
cylinder sleeve to be on ring travel area. Measure ring
gap with a feeler gauge.
(3) Minimum ring gap on all rings is 0.011
inch. If necessary, file ring ends with a fine cut file to
obtain correct clearance.
(4) Measure ring-to-groove clearance (top of
ring to top of groove in piston ). Specified clearances are
as follows: top compression ring, 0.002 inch to 0.004
inch; second compression ring, 0.0015 inch to 0.0035
inch; and oil control rings, 0.001 inch to 0.003 inch.
(5) After rings have been properly fitted,
NOTE
When measuring clearance between
a piston and a used sleeve. make
certain that piston is inserted into the
sleeve far enough so measurement is
taken in area of piston ring travel
within sleeve.
(5) Piston skirt diameter of a new piston is
3.4365 inches to 3.4385 inches, measured at right
angles to the piston pin; inside diameter of a new
cylinder sleeve is 3.4379 inches to 3.4385 inches.
Deviation from these measurements will indicate amount
of wear on piston or cylinder sleeve. The piston or
cylinder sleeve, or both, must be replaced if the
clearance exceeds 0.008 inch.
(6) New piston rings must always be used
with new pistons. If engine has been in service for some
time, even though the same pistons are used again, it is
advisable to use new rings when the engine is
reassembled.
e. Connecting Rod Inspection.
(1) Wash connecting rod assembly with SD.
(2) Measure outside diameter (OD) of piston
pin to determine wear. Specified diameter of a new
piston pin is 0.8591 inch to 0.8591 inch.
(3) Specified inside diameter of connecting
rod bushing is 0.8593 inch to 0.8596 inch. These pin
and bushing dimensions provide a clearance of 0.0001
inch to 0.0005 inch; clearances of up to 0.002 inch are
permissible. If clearance is close to or beyond this limit,
replace connecting rod bushing.
(4) Inspect connecting rod bearings (10, fig.
3-35) for scoring, chipping, corrosion, cracking, or signs
of overheating; discard bearing shells if any of these
conditions are apparent.
(5) Back of rod bearings should be inspected
for bright spots and discarded if any are found, as this
condition indicates they have been moving in their
supports. Inspect rod bearings for wear. Specified
inside diameter of rod bearings when installed with
bearing cap retaining bolts tightened to specified torque
is 2.1239 inches to 2.1254 inches. This provides a
running clearance of 0.0015 inch to 0.0030 inch; new
bearings must be installed when this clearance exceeds
0. 006 inch. Refer to paragraph 3-21 and measure the
connecting rod bearings for wear and clearance with the
crankshaft in a similar manner. If crankshaft is worn or
damaged it must be replaced.
f. Piston Rod Alignment Inspection.
(1) If wear on rod bushings or bearings
indicates rod may be out of alignment, place rod and
piston on aligning fixture for checking.
(2) With piston and connecting rod assembly
clamped onto aligning fixture, swing rod into a horizontal
position parallel to floor. With piston held diagonally to
rod (piston head pointing to floor), observe space
3-43
install them on piston, using a piston ring remover and
installer. Take care not to spread rings more than
necessary. Stagger ring gaps evenly around piston so
that no two are in line.
NOTE
Oil all rings and pistons before
installing them in cylinder sleeve.
i. Replacement of Connecting Rod Bushing and
Pin.
(1) connecting rod bushing (7, fig. 3-35) is
worn, old bushing may be pressed out and a new
bushing pressed in.
Specified inside diameter of
connecting rod bushing is 0.8593 inch to 0.8596 inch and
diameter of piston pin is 0.8591 inch to 0.8593 inch; this
provides a clearance of 0.0000 inch to 0.0005 inch
between pin and bushing. Maximum clearance or fit of
0.002 inch is allowable before replacement.
(2) When there is no wear between piston
and pin, but wear exists between bushing and pin, install
a new bushing and ream to fit a standard size pin. If
there is wear on both the piston and bushing, an oversize
pin of 0.005 inch or 0.010 inch may be used which will
require reaming of piston and connecting rod bushing to
fit.
(3) bushing is loose in the connecting rod, it is
recommended that rod be replace as even a new
bushing would fit loosely.
j. Assembly.
(1) Install one of the piston pin retainer rings
(5, fig. 3-35) in one end of the piston pin hole in piston.
(2) Immerse piston in boiling water for about 5
minutes. Then insert upper end of connecting rod into
piston and insert piston pin (6). Pin to connecting rod is
a very light push fit.
(3) Install other piston pin retainer at opposite
end of piston pin.
k. Installation.
(1) When installing pistons and connecting
rods, be sure to place them in their respective cylinders
with number on bearing cap opposite camshaft side of
engine.
(2) Place ring compressor over piston rings
making certain that rings are wholly in their grooves
before tightening compressor.
Tighten compressor
gradually, pausing to move it sideways to be sure the
rings are free. Compress rings as much as possible.
(3) Place piston connecting rod in cylinder
sleeve with lower end of connecting rod aligned with
crankshaft. Using the wooden handle of hammer, tap
on upper end of piston to push it out of compressor and
into sleeve.
(4) Place upper half of bearing in position on
connecting rod and install bearing cap and lower half of
bearing, making certain identifying marks are aligned.
(5) Install connecting rod nuts; torque to 45 50
ft-lbs.
(6) Check connecting rod side play at bearing
journal. Specified clearance is 0.003 inch to 0.009 inch.
(7) Replace items which were removed in
order to remove pistons and connecting rods.
3-23. Valves and Rocker Arm Assembly
a. Description. Intake and exhaust valves (fig.
3-36) are high tensile alloy steel carefully heattreated to
develop special properties required for valve service.
Each valve stem is accurately ground to size and
hardened. Hardened intake and exhaust valve seat
inserts are installed in the cylinder head. Valve guides,
made of high tensile iron, are pressed into the cylinder
head. Valve springs are held in place by a regular spring
retainer on the valve and tapered valve spring retainer
locks. Release type cap allows valve to rotate slightly
each time valve is opened and repositioned on its seat.
The rocker arm assembly, consisting of two rocker arms
for each cylinder, is mounted on a common rocker arm
shaft supported by rocker shaft brackets attached to the
cylinder head. The push rods extend down through the
cylinder head, cylinder block, and into valve lifters which
are held in place by the camshaft. Upper ends of push
rods are concave to receive ends of valve lash
adjustment screws threaded into one end of rocker arm.
Other end of rocker arm actuates valves through push
rods. When push rods are forced upward by camshaft
lobes, rocker arm forces valve open. Tension of valve
spring closes valve when push rods move downward.
An oil feed line from the engine oil gallery, connected to
the side of the cylinder head, leads to an oil feed in line
tube. Both ends of shaft are blocked, forcing oil out
holes at each rocker arm location and into a drilled
passage in each rocker arm, providing lubrication for the
assembly. Oil spilled down over push rods and valve
springs drains back to oil pan through overflow tube.
3-44
b. Valve Mechanism Service.
(1) Operations not requiring cylinder head
removal:
(a) Adjustment of valve clearance (TM
10-3930-618-20).
(b) Replacement of valve push rods.
(c) Replacement of valve lifters.
(d) Replacement of valve springs.
(e) Replacement of any part of rocker
arm assembly.
(2) Cylinder head must be removed to
perform the following operations:
(a) Replacement of valves.
(b) Replacement of valve guides.
(c) Grinding or reseating valves.
(d) Replacement of valve seat inserts.
c. Rocker Arm Removal and Inspection. The
following operations may be performed without
removing the engine from truck, and if performed
in the truck disregard (1) below.
(1) Remove engine from truck (para 3-19).
(2) Remove rocker arm cover (3, fig. 3-30).
(3) Remove line assembly (5, fig. 3-37) from
cylinder head and rocker arm shaft (3).
Figure 3-36. Intake and exhaust valve assembly.
3-45
1 Capscrew
13 Line assembly
2 Clip
14 Elbow
3 Shaft
15 Camshaft
4 Elbow
16 Key
5 Line assembly
17 Lockwasher
6 Rocker arm
18 Capscrew
7 Bracket
19 Gear
8 Rocker arm
20 Retainer
9 Washer
21 Thrust plate
10 Expansion plug
22 Valve lifter
11 Adjusting screw
23 Push rod
12 Elbow
Figure 3-37. Valve operating mechanism and camshaft.
(4) Remove capscrews (1) and washers (9)
attaching rocker arm shaft brackets (7) to cylinder head,
and lift rocker arm assembly from cylinder head.
(5) Remove elbow (12) and line assembly
(13) from collar at center of rocker arm shaft.
(6) Remove rocker arm brackets and collar
from shaft.
(7) Inspect rocker arm bore for wear.
Specified clearance between shaft and bore is 0.001 to
0.0035 inch, and must not exceed 0.007 inch. If
clearance is greater than allowable limit, rocker arm
must be replaced. Inspect machined ends (valve stem
end) of rocker arms for signs of wear. If not excessively
worn, contact surfaces may be refaced on a valve lathe.
(8) Inspect the rocker arm shaft for wear.
Remove expansion plugs (10), and clean oil holes with
cleaning solvent (Spec.
P-S-661), and dry with
compressed air.
d. Rocker Arm Installation.
3-46
inch, they should have a load of 122- to 131-pounds.
Spring free length is 23 / 32 inches. Replace any springs
that are found to be weak or cracked.
(d) Install valve spring by a direct
reversal of (b) above. Make certain that the release type
rotors (30, fig. 3-30) are installed on exhaust valve
stems only.
(e) Install cylinder head (para 3-20).
(2) Cylinder head not removed from engine.
(a) Remove rocker arm cover and
rocker arm assembly (c) above.
(b)
Crank engine to make certain that piston
in cylinder from which valve springs are to be removed,
is at top dead center. Using two heavy screwdrivers, or
suitable pry bars, and using the manifold as a fulcrum,
pry down on valve spring retainer (28) until valve spring
retainer locks (29) can be removed. Remove valve
spring retainer locks and carefully release tension on
valve spring. Remove valve spring retainer and valve
spring.
(c) Perform procedures in (1) (c) and
(d) above.
(d) Install rocker arm assembly and
rocker arm cover ( d above).
h. Removal and Inspection of Valves, Guides, and
Seat Inserts.
(1) Remove rocker arm assembly. Refer to (
c above).
(2) Remove cylinder head from cylinder block.
Refer to paragraph 3-20.
(3) Remove valve springs. (Refer to ( g
above).
(4) Remove valves from cylinder head. Place
valves in a rack as they are removed from cylinder head
so they can be identified and reinstalled in their original
positions.
(5) Clean carbon from valves and valve
inserts (21 and 22). Clean carbon from valve guides (14)
using a valve guide cleaning tool.
(6) Replace valves if they are cracked, bent,
or worn beyond allowable limits. Specified diameter of
valve stems is 0.3405 inch to 0.3415 inch. Specified
clearance of valve stems in valve guide is 0.0015 inch to
0.0035 inch. If clearances exceed specified limits, valve,
guide, or both should be replaced.
(7) Valve guides (14) are removed by
pressing them out through bottom of cylinder head, using
a valve guide removing tool.
(8) New valve guides are installed by inserting
upper (chamfered ) end of guide on guide installing tool
and pressing into cylinder head until top of guide is 7 / 32
inch above top surface of cylinder head. Both intake and
exhaust valve guides are positioned to the same depth in
head.
(9) After valve guides have been installed,
insert valve stems into guides to check for proper
clearances between valve stems and valve guides.
Specified clearance if 0.0015 inch to 0.0035 inch.
CAUTION
The rocker arms are not designed to
contact the valve stems at the center,
but 1/16 inch off center. Do not
bend rocker arms to make them line
up center-to-center with valve stems.
(1) Make certain plugs are tight in ends of
shaft.
(2) Install exhaust rocker arms (7, fig. 3-37),
shaft support, and intake rocker arm (6) in order shown.
Assemble last half in same manner, then install second
washer and cotter pin.
(3) Install oil tube elbow (12) and line
assembly (13) in collar at center of shaft. Make certain
elbow enters hole in shaft.
(4) Install rocker arm assembly on cylinder
head, making certain that shaft supports are positioned
with longer section down.
(5) With valve lash adjusting screws (11)
correctly seated in push rods, tighten shaft support stud
nuts and capscrews. Torque to 18 to 22 ft-lbs.
(6) Install oil line assembly (5) between rocker
arm shaft and cylinder head.
(7) Adjust valves for correct clearance (TM
10-3930-618-201.
(8) Install rocker arm cover making certain
gasket is in good condition and properly positioned, then
install vent hose.
e. Removal and Inspection of Lifters and Push
Rods.
(1) Remove rocker arm assembly ( d above).
(2) Withdraw push rods (23). Inspect ball and
cup ends for signs of wear; polish out any nicks or score
marks. If push rods are bent, twisted, or damaged they
must be replaced.
(3) If inspection indicates valve lifters (22)
should be removed, refer to paragraph 3-24.
f. Installation of Lifters and Push Rods.
(1) Install lifters, reversing procedures in e
above.
(2) Install push rods with cup end to top of
cylinder head.
(3) Recheck to make sure that push rods are
firmly seated in lifters.
(4) Install rocker arm assembly and rocker
arm cover ( d above).
g. Removal, Inspection, and Installation of Valve
Springs.
(1) With cylinder head removed from block.
(a) Remove cylinder head (para 3-20).
(b) Place cylinder head on end, depress
valve springs (27, fig. 3-30) with a spring depressing tool
and remove spring retainer locks (29). Release valve
spring depressing tool and remove valve spring retainer
and valve spring.
(c) Inspect valve springs for cracks.
Both intake and exhaust valve springs should have a
load of 42- to 47-pounds when compressed to length of 1
27 / 32 inch. When compressed to a length of 1 13/32
3-47
(d) Grinding wheels of 30°, 45°, and
If clearance is less than specified minimum, guides must
be reamed to obtain proper clearance. Inside diameter
of valve guide is 0.343 inch to 0.344 inch.
(10) Valve seat inserts (21 and 22) are
replaceable. Standard seats are available for service.
Inspect valve seat inserts. If loose, cracked, or pitted
new inserts must be installed. Inserts are a shrink fit in
cylinder head. Remove insert shown in figure 3-36 by
electric welding a bead around inside circumference of
insert on beveled portion. Allow insert to cool, then lift
out.
CAUTION
Protect machined surfaces from arc
splatter.
(11) Care must be exercised when installing
new valve seat inserts. Inserts are installed into cylinder
head with a 0.0025 inch to 0.0045 inch shrink fit and
must be started in place "true" with counterbore in
cylinder head.
(a) Be sure insert counterbores in
cylinder
head are clean and free of burs.
(b) Thoroughly chill insert with dry ice.
(c) Clean counterbore with compressed
air and start insert into counterbore (valve seat side up).
(d) Using a valve seat installer tool,
drive insert down tight into counterbore. This operation
must be done quickly, while insert is cold.
After
installation, stake valve seat in position with a center
punch at two or three points around edge of seat..
(e)
It will be necessary to refinish valve seat
inserts with a grinder ( i below).
i. Valve and Valve Seat Grinding.
(1)
Before installing new valves or valves
previously used, valve seats in cylinder head should
be inspected for proper valve seating.
If
previously used valves are to be reinstalled, valve stems
should be cleaned and valve faces ground to an angle of
45°. When refacing valves, remove just enough to clean
up seat, removing all evidence of pitting and grooving.
(2)
Valve guide should be cleaned with a
valve guide cleaning tool.
If bore of valve guide is
worn oblong, or if valve head is warped relative to valve
stem, damaged parts must be replaced.
(3) When new valve seat inserts are installed,
or previously used inserts refaced, refinishing must be
done with a valve grinder set because of very hard valve
seat material.
NOTE
It is very important that valve grinder
set
be
used
according
to
manufacturer’s directions.
(4) The usual equipment furnished with the
valve seat grinder set includes the following items:
(a) Valve seat grinder.
(b) Dial gauge.
(c) Tool pilot.
60°.
(5) Install tool pilot in position in valve guide.
Use a 45° grinding wheel for refacing valve seat and use
the 30° to 60° grinding wheels for narrowing the seat
width to the specified 1 / 16 inch for intake and 3 / 32
inch for exhaust valve seats.
(6) After a grinding wheel has been used
several times, cutting angle of stone must be reground
and made true to obtain proper seat angle.
(7) After valve seats have been ground, use
dial gauge to check concentricity of valve seats relative
to valve guides. Total runout of valve should not exceed
0.002 inch.
(8) After valve seats have been ground,
valves may be inserted in position in cylinder head and
lapped in place, using fine grain valve lapping
compound. After lapping, contact between valves and
seats may be checked by wiping a thin film of Prussian
Blue on each valve seat, setting valve in place, and
bouncing each valve once on its seat.
NOTE
Do not revolve valve when checking
seat.
(9) If valve seats are properly ground, a
continuous thin blue line will be evident around face of
valve.
(10) Clean valves and block and install valves
h above.
(11) Install cylinder head (para 3-20).
3-24. Camshaft, Bearings, and Valve Lifters
a. Description. The camshaft is manufactured of
drop forged, open hearth steel. case hardened at the
cams and journals, and is located in the rightside of the
engine block (as mounted in truck). Rigidly supported by
four replaceable bronze bearings, the camshaft's end
play is controlled by an end thrust plate at the timing gear
end. The valve lifters ride on precision ground cams of
the shaft and provide the timing link between the
camshaft and valves through the push rods and rocker
arm assembly. The camshaft bearings seldom need
replacement or repair, and since it is necessary to
disassemble the entire crankcase to effectively check
bearing to camshaft clearances, it is recommended that
camshaft bearings be checked every time crankcase
disassembly allows access to the camshaft and
bearings.
b. Removal.
NOTE
It is recommended that camshaft be
replaced only when engine is removed
from truck. However. in an emergency it
is possible to replace it without engine
removal. Instructions below apply to
both methods. however. if engine has
already been removed from truck.
disregard (a) and (e).
3-48
(c) Remove distributor (TM 10-3930-
1. Remove gear retaining ring (20,
61820).
fig. 3-37.
(d) Remove steering axle assembly
2. Install gear puller and remove
gear (19) and key (16) from shaft.
3. File back of gear hub (side
facing cylinder block). This permits pressing gear further
onto shaft, reducing thrust plate clearance.
(c) Check camshaft journals for out-of
round and deviations from design diameters.
Specified diameters of camshaft journals are1. 1.248 inch to 1.249 inch for the
flywheel end.
2. 1.998 inch to 1.999 inch for the
intermediate and gear end journals.
(d) Check valve lifters for wear. Valve
lifters fit in their bores is 0.0010 inch to 0.0025 inch. If
wear exceeds 0.0035 inch, lifters should be replaced.
Lifters must be free to rotate in their bores, otherwise
scuffing will result.
(2) Camshaft bearings.
(a) Check camshaft bearings for
excessive looseness, wear, or other damage.
(b) Check inside diameter of bearings
for roundness and conformance to specifications, which
are 1. 1.2510 inch to 1.254 inch for the
bearing at the flywheel end of engine.
2. 2.0010 inches to 2.004 inches for
the intermediate and gear end camshaft bearings.
(c) If clearance between camshaft
journals and bearings exceeds 0.0065 inch, new
camshaft bearings must be installed.
d. Installation.
(1) Camshaft bearings.
(a) Install camshaft bearings with
camshaft bearing installing tool (fig. 3-38).
NOTE
The bearing nearest the flywheel end of
block is 1.0 inch wide, intermediate is 7 /
8 inch wide, and the gear end bearing is
1 1/8, inch wide.
(b) Drive bearings into place with a
driving bar.
They do not require reaming after
installation.
(c) Install new camshaft hole plug in
open end of bore in the flywheel housing mounting face
of the cylinder block.
(2) Camshaft and valve lifters. Install by
direct reversal of procedures in b above.
(para 2-14).
(e) Remove timing gear cover (para 325).
(f) Remove lubricating oil pump (para
3-13).
(g) Rotate crankshaft until openings in
camshaft gear align with thrust plate capscrews (18, fig.
3-37), then remove capscrews.
(h) If engine is in truck, push valve
lifters (22, fig. 3-37) upward in cylinder block. In most
cases. they fit tight enough in the lifter bore to stay out of
the way of the cam lobes. If they do not stay out of the
way voluntarily, they may be lifted separately by rotating
the camshaft while removing it.
(i) If the engine has been removed
from truck, turn engine on its side, push the lifters up into
their bores and they will stay out of the way of the
camshaft lobes during removal.
(j) Remove camshaft by drawing it out
of the cylinder block at the gear end. Be careful to keep
it aligned with bore so that the camshaft bearings will not
bind on the camshaft journals.
(k) Remove valve lifters from the cylinder
block by withdrawing them from their bores.
(2) Camshaft bearings.
(a) Remove camshaft as described in
(11 above.
(b) Remove flywheel housing (para 326).
(c) Remove camshaft hole plug (4, fig.
3-32) from flywheel end of camshaft bore.
(d) If removing and installing tool is not
available, carefully cut through gear end bearing (5) with
a hacksaw blade, being careful not to cut into crankcase.
(e) Break bearing with hammer and
chisel and remove it.
(f) Remaining bearings (6 and 7) can
be removed as outlined in (d) and (e) above, or with
installing tool (fig. 3-38).
c. Inspection and Repair.
(1) Camshaft and lifters.
(a) Check camshaft thrust clearance
(fig. 3-39) by inserting feeler gauge between thrust plate
and camshaft bearing surface (fig. 3-39). Specified
thrust clearance is 0.003 inch to 0.008 inch.
(b) If end clearance exceeds maximum
wear limit of 0.014 inch, remove gear from camshaft and
3-49
mount is located in the lower portion of the timing gear
cover casting.
a. Removal and Installation of Timing Gear Cover.
NOTE
The following procedures apply to
removal of cover with engine
mounted in truck. if engine is out of
truck, disregard (1) and (5) below.
(1) Remove radiator (TM 10-3930-618-201.
(2) Remove cooling fan (TM 10-3930-618-20).
(3) Remove crankshaft pulley (para 3-21).
(4) Remove governor (para 3-9).
(5) Remove support capscrews (9, fig. 3-40)
and raise rear end of engine approximately 2.0 inches,
and block the engine in this position. This takes weight
of engine off mounting pad on timing gear cover.
(6) Remove capscrews (18, 20, and 22) nuts
(1) and lockwashers (17, 19, and 21) attaching timing
gear cover (4) to front plate (6) and oil pan.
Do not attempt to pry cover off. Tap cover lightly with
wood or plastic mallet to remove.
(7) To install, reverse removal instructions
above.
b. Inspection and Repair.
(1) Inspect timing gear cover for cracks,
dents, breaks, or other damage which could prevent a
secure seal of the timing gear cover.
(2) Replace gaskets.
(3) Replace defective parts.
c. Timing Gears.
(1) Refer to paragraphs 3-21 and 3-24 for
crankshaft and camshaft timing gears.
(2) Refer to paragraph 3-9 for governor timing
gear.
(3) Check backlash of timing gears with a dial
indicator. One or more of the mating gears should be
replaced if backlash exceeds 0.007 inch.
Figure 3-38. Camshaft bearing installation.
Figure 3-39. Checking camshaft thrust clearance.
3-25. Timing Gears and Cover
The timing gear housing at the rear end of the engine
contains a train of three helical gears; a crankshaft gear
which is pressed and keyed on the crankshaft, a
camshaft gear, and a governor gear driven by the
camshaft gear. Gear train is splash lubricated by excess
oil from engine oil system relief valve. The rear engine
3-50
1 Nut
13 Insulator
2 Stud
14 Insulator
3 Stud
15 Washer
4 Timing gear cover
16 Nut
5 Gasket
17 Lockwasher
6 Plate assembly
18 Capscrew
7 Gasket
19 Lockwasher
8 Stud
20 Capscrew
9 Capscrew
21 Lockwasher
10 Washer
22 Capscrew
11 Washer
23 Oil seal
12 Sleeve
Figure 3-40. Timing gear cover and rear support.
gear from flywheel without first expanding it.
(5) Loosen capscrews on oil pan (para 3-12)
to relieve pressure on pan section of oil seal in flywheel
housing.
(6) Remove two flywheel capscrews (7)
opposite each other, and install a pair of guide studs.
(7) Remove remaining housing capscrews
and slide flywheel housing off over guide studs.
(8) If necessary, remove oil seal (1).
b. Inspection and Repair.
(1) Inspect oil seals for cracks, tears,
deterioration, deformation, or other damage.
(2) Inspect oil seal flange on engine side of
flywheel for nicks or burs. If defective, smooth with a fine
stone or crocus cloth.
(3) Remove all burs and nicks from mating
surfaces of the flywheel and crankshaft flange.
3-26. Flywheel, Ring Gear, and Housing
a. Removal.
(1) Remove transmission (para 3-16).
(2) Remove two of the flywheel mounting
capscrews (10, fig. 3-41), which are opposite each
other, and install a pair of guide studs.
(3) Remove remaining mounting capscrews,
and slide flywheel (11) off over guide studs.
(4) If inspection indicates necessity of
removing ring gear proceed as follows:
(a) Grind notch through gear (8) at
route of one of the teeth.
CAUTION
Be certain not to notch flywheel.
(b) Expand ring gear and drive from
flywheel (11).
CAUTION
Do not attempt to drive notched ring
3-51
CAUTION
It is extremely important that all burs
and nicks be removed from mating
surfaces of flywheel and crankshaft
flange. If surfaces are not smooth
and true, the flywheel may wobble.
Flywheel wobble would result in improper torque converter operation,
engine vibration, and shortening of
the life of crankshaft bearings and
other parts.
(4) Inspect flywheel housing for cracks,
bends, nicks, holes, stripped threads, corrosion, and
other damage which would interfere with its proper
operation.
(5) Replace defective parts as authorized.
c. Installation.
(1) Install flywheel and housing by reversing
procedures in a above.
(2) Install new inner and outer oil seals
whenever any signs of leakage appear, and whenever
engine is overhauled.
NOTE
Flywheel can be installed in only one
position on the crankshaft flange
because on of the capscrews is offset
slightly. Any time a new flywheel is
installed. be certain to check the
timing marks of the old and new
flywheels.
(3) To install a new ring gear (a) Heat ring gear to approximately 400
degrees Fahrenheit (400°F.). The desired temperature
produces a dull red heat visible in the dark.
(b) Place heated ring gear on flywheel
with chamfered ends of gear teeth away from flywheel
shoulder, and toward the oil seal flange. The flywheel
should be at room temperature.
(c) Drive ring gear down tight against
shoulder of flywheel.
(d) After the installation of housing,
flywheel, and ring gear, and before installation of starting
motor and transmission, dial indicate both flywheel and
housing as follows:
1. Attach a dial indicator to housing, at
one of the transmission mounting holes, and check
flywheel for runout. Runout should not exceed 0.005
inch.
2. Attach dial indicator to center of
flywheel, and check flywheel housing for runout, which
should never exceed 0.010 inch.
1 Outer oil seal
2 Housing
3 Cover
4 Lockwasher
5 Capscrew
6 Lockwasher
7 Capscrew
8 Ring gear
9 Lockwasher
10 Capscrew
11 Flywheel
12 Dowel
13 Inner oil seal
Figure 3-41. Flywheel, ring gear, and housing.
3-52
TM 10-3930-618-34
THESE PAGES ARE MISSING FROM ORIGINAL DOCUMENT
PAGE 3-53
and
PAGE 3-54
CHAPTER 4
REPAIR OF HYDRAULIC SYSTEM
Section I. HYDRAULIC SYSTEM
(9) Remove plug (15) and remove relief valve
parts (10 through 14).
c. Cleaning and Inspection.
NOTE
All parts should be thoroughly
cleaned in cleaning solvent (Spec. PS-661) and dried with compressed air
before inspection. After inspecting,
reclean serviceable parts, apply a
coating of oil and wrap the parts in
clean, lint-free cloths until the pump
is reassembled.
(1) Clean in accordance with above note.
(2) Using a 2-inch inside micrometer,
measure bore in body (18) near the front. The bore
diameters should not exceed 1.770 inch.
(3) It is normal for gears to cut shallow
grooves with tips of teeth on the inlet side. Measure
depth of groove cut by idler gear (26), which will be
slightly deeper than groove cut by drive gear (25).
Discard body if groove depth exceeds 0. inch.
(4) Normal grooves (tracks) have a smooth
texture radially and are of slightly darker color than rest
of body.
(5) If grooves have a sandpaper like texture
and are light gray or silver in color (when dry), oil in the
system is either dirty or foamy. Check for dirty oil,
clogged filters, and leaks in pump suction line.
(6) Check seals (1 and 2) for nicked or frayed
lips or signs of leakage. Replace seals if conditions
exist.
(7) Inspect gear journals on both shafts for
general condition. Small radial scratches left by particles
in the oil are normal. If journal surfaces are blackened
and can be easily scratched, they have lost their
hardening, and gear assemblies must be replaced.
Polish journals with 400 grit sandpaper or finer.
(8) Measure gear assemblies for following
Journal
diameter-0.872 inch
dimensions: (a)
minimum.
(b) Gear length-1.319 inch minimum.
(c) Gear diameter (outside)-1.754 inch
minimum.
(9) Inspect gears for burs which could cut
faces of bushings. Remove burs with fine hone.
(10) Inspect bushings (7 and 24) for dents,
deformations, and for grooves cut in faces by foreign
particles.
(11) Hone front and rear faces of bushings with
an extra fine stone, moving stone in circular motion.
4-1. General
In this equipment all lifting, tilting, and steering units are
operated by means of hydraulic pressure. Service and
adjustment of the hydraulic system is described in TM
10-3930-618-20. This section will cover direct and
general support maintenance of the hydraulic system
components.
4-2. Pump Assembly
a. Removal. Refer to paragraph 2-10 for hydraulic
pump removal.
NOTE
Clean outside of pump prior to
starting disassembly.
b. Disassembly.
(1) Remove screws and separate flange from
pump body (fig. 4-1).
NOTE
To prevent chance of leakage at
reassembly, avoid scoring or nicking
of mating cover, housing, and
adapter machined surfaces. Do not
use a screwdriver to pry components
apart. Use a loft hammer and tap
gently to loosen the sections on
dowel pins.
(2) Remove screws and separate flange (3)
from body (18).
(3) Remove seals (1 and 2).
(4) Remove packing (5) and front O -rings (4)
and O -rings (6).
(5) Tip pump to front and allow bushings (7)
to slide out into hand. If bushings do not slide out, jar
them loose by tapping side of pump body with a soft
hammer.
NOTE
Identify bushings as "front" to insure
proper assembly. Interchanging front
and rear bushings will greatly reduce
pump efficiency.
(6) Tip pump body to rear and lift out gears
(25 and 26).
(7) Remove bushings (24) in same manner as
bushing (7) (5 above). Remove rear packings and rings.
(8) Normally, plug (23) will be forced out by
spring (20) when flange (3) is removed. If not, turn a 1/4
inch screw into plug and pull out the plug.
Then remove spool (21) and spring (20).
4-1
Replace spool if any land diameter is less than 0.748
inch.
(18) Clean deposits from balance orifice in
spool using a fine, soft wire. Also check slow orifices
and clean as necessary using fine, soft wire.
(19) Check both springs (20 and 14) for bent or
deformed condition. Spring (20) should have a free
length of 3 1/2 inches. Spring ( 14) should have a free
length of 7/8 inch. Replace springs if bent, deformed, or
stretched.
d. Assembly
(1) Reverse procedures in c above.
(2) Do not reuse packings and backup rings.
(3) Apply small amount of heavy grease to
packings (6) and backup rings (5) to hold them in
position on bushings (7). Slide bushings into bores, do
not tap or force them in any way. Make sure packings
and backup rings remain in place. Apply a coat of light
oil to bushing surfaces for ease of installation.
(4) Apply coat of light oil to gear faces and to
shaft journals before installing.
(5) Insert spring (20) in spool (21) and insert
spool in body bore. Assemble O -ring (22) to plug (23),
coat with light oil, and press plug into bore until flush with
face of body. Then install flange (3) on body (18). Make
sure O -ring (4) is in place.
(6) Install relief valve parts ( 10 through 14) in
order shown and tighten plug (15) until ii: bottoms.
e. Installation. Refer to paragraph 2-10 for pump
installation.
NOTE
Do not attempt to remove all cuts as
the face Will probably become out-of
square with the outside diameter.
CAUTION
Use care when honing to avoid
breaking sharp edge between face of
bushing and outside diameter.
(12) Measure entire bore of each bushing.
Bores will be slightly oval due to wear but must not
exceed 0. inch at any point or bushing must be
replaced.
(13) Measure length of bushings at a number
of points. Shortest length must not be less than 1.055
inch or bushing must be replaced.
(14) Gears will sometimes make small cuts in
rectangular land near flat of bushings. Depth of these
cuts must not exceed 0.002 inch or bushing must be
replaced.
(15) Inspect for erosion on bushing faces near
rectangular lands and in lube oil slots. Erosion at these
points is caused by air in oil. Replace bushings having
erosion at these points. Slight erosion on outside
diameters and on flats is normal.
(16) Visually inspect spool (21) for erosion and
scratches. Insert spool in bore and check that it slides
freely in bore.
(17) Measure diameters of spool lands.
4-2
1 Seal
2 Seal
3 Mounting flange
4 O-ring
5 Packing
6 O-ring
7 Bushing
8 Bushing dowel
9 O-ring
10 Setscrew
11 Spring
12 Relief valve cone
13 Spool
14 Relief spring
15 Relief port plug
16 O-ring
17 Plug
18 Body
19 Body dowel
20 Valve spool spring
21 Spool
22 O-ring
23 Plug
24 Bushing
25 Drive gear
26 Idler gear
Figure 4-1. Hydraulic pump disassembly and reassembly.
4-3. Hydraulic Control Valve
a. Description. The hydraulic system control valve
contains two plunger sections; an inlet section, and an
outlet section. Each of the sections may be replaced
separately. All parts of the sections may be replaced
individually except the plunger section housings and their
selectively-fit plungers, which must be replaced as units.
b. Removal. Refer to paragraph 2-12 for hydraulic
control valve removal.
c. Disassembly. Refer to figure 4-2 and
disassemble as follows:
CAUTION
It is extremely important that all parts
be kept clean at all times, and that all
machined surfaces be protected from
nicks, scoring, gouging, and other
damage.
Disassemble
valve
assembly only as far as is necessary.
(1) Separate the control valve into its major
sections by removing nuts (19) from tie rods (44) and slip
the sections off of tie rods.
(2) Disassemble defective sections using
figure 4-2 as a guide.
d. Cleaning and Inspection.
(1) Clean all parts in (SPEC. P-S-661).
(2) Inspect springs for cracks, wear,
deformation, or signs of weakness.
(3) Inspect all seals for cracks, cuts, or other
damage.
(4) Inspect all machined surfaces for nicks,
scratches, gouges, or other damage which could cause
internal or external leakage.
(5) Inspect all housings for cracks, stripped
4-3
threads, or other damage which could affect operation.
(6) Inspect plungers and plunger bores for
scoring, chips, nicks, cracks, or other damage which
could result in internal or external leaks.
(7) Replace seals and defective parts.
e. Refer to figure 4-2 as a guide to assembly.
NOTE
Recheck each part before assembly
for dirt or damage.
(1) Reverse procedures in c above.
(2) Coat all seals with approved hydraulic coil
before installing.
(3) Use new packings.
(4) Tighten nuts (19 and 45) to 18 ft-lbs
torque.
f.
Installation. Refer to paragraph 2-13 for
control valve installation.
g.
Relief Valve Adjustment. Refer to figure
4-2 and adjust as follows:
(1)
Remove the plug from the inlet port
elbow and install a pressure gage. The gage must be
calibrated to at lease 2,000 psi.
(2) Remove the capnut (1) from the adjusting
screw (41 and loosen the locknut (3).
(3) Start the engine and accelerate to high
speed.
(4) With the engine running at high speed,
operate the tilt control lever to run the tilt cylinders to the
end of their stroke. Hold the tilt control lever in operate
position through step (5 below.
(5) Adjust the adjusting screw to obtain a
gage reading of 1,950±50 psi.
(6) Hold the screw in position and tighten the
locknut.
(7) Check the setting with a capacity load on
the forks before removing the gage. Readjust as
necessary.
(8) Shut off the engine.
(9) Install the capnut over the adjusting screw,
remove the pressure gage, and install the plug.
Key to figure 4-2
1 Capnut
2 Washer
3 Locknut
4 Adjusting screw
5 Spring
6 Poppet
7 Plug
8 Packing
9 Backup ring
10 Packing
11 Spring
12 Piston
13 Poppet
14 Packing
15 Backup ring
16 Poppet
17 Cup
18 Packing
19 Nut
20 Plug
21 Packing
22 Inlet section
4-4
23 Packing
24 Screw
25 Plate
26 Wiper
27 Packing
28 Tilt plunger
29 Tilt plunger housing
30 Capscrew
31 Cap
32 Capscrew
33 Spring seat
34 Spring
35 Spring seal
36 Plate
37 Wiper
38 Packing
39 Packing
40 Outlet section
41 Spring
42 Poppet
43 Packing
44 Tie rod
Figure 4-2. Hydraulic control valve.
4-5
compressed air. If filler screen cannot be cleaned,
replace with new filler screen.
d. Reassembly. Reverse the procedure as
outlined in c above.
e. Installation. Refer to TM 10-3930-618-20 for
hydraulic tank installation.
4-4. Hydraulic Reservoir
a. Description.
The purpose of the hydraulic
reservoir is to hold sufficient oil for the entire hydraulic
system. It consists of a 7.2 gallon tank, combination filler
and plug and dipstick, and a washable breather cap. It is
attached to the frame on the left side of the truck. The
suction line on one end of the tank is located near the
bottom to prevent air from being drawn into the pump,
causing pump noise and erratic operation of the system.
The return line is connected to the opposite end of the
tank, also near the bottom. This is to help prevent
foaming of the oil. A magnetic drain plug is provided on
the bottom of the tank to drain out all the oil when
necessary. A screen is located in the, auction line
between the reservoir and pump at the junction midway
of the line.
CAUTION
Always refer to LO 10-3930-618-12.
NEVER USE BRAKE FLUID. Make
sure containers and surrounding
parts are clean when filling tank, to
prevent dirt from contaminating the
oil.
b. Removal. Refer to TM 10-3930-618-20 for
hydraulic tank removal.
c. Disassembly. Refer to figure 4-3 and
disassemble the tank as follows:
(1) Remove all plugs, fittings, breather cap
and dipstick from the reservoir.
(2) Clean outside of reservoir with cleaning
solvent.
(3) Thoroughly flush reservoir with solvent to
remove dirt or other sediments.
(4) Inspect reservoir for bad dents, cracks,
and leaks. Replace reservoir if cracked or badly dented.
(5) Inspect for damaged or worn threads in
openings.
Repair damaged threads by chasing if
practical, otherwise replace the reservoir.
(6) Check filler screen for clogging or
damage.
Clean screen with cleaning solvent and dry with
Figure 4-3. Hydraulic reservoir.
Section II. REPAIR OF HYDRAULIC LIFT CYLINDERS
should not be called upon to hold any bending action due
to misalignment.
b. Removal.
Refer to paragraph 2-12 for tilt
cylinder removal and installation.
c. Disassembly.
Refer to figure 4-4 and
disassemble the tilt cylinder as follows:
(1) Secure tilt cylinder in bench vise. Be
careful not to deform cylinder.
(2) Loosen capscrew in yoke (27) and
unscrew yoke from plunger rod (16).
4-5. Tilt Cylinders
a. Description. The two double acting till cylinders
provide the means for tilting the mast assembly 30
forward and 100 back. They are located under cowls on
each fender. Action of the tilt cylinder is a straight line
motion. Any misalignment between the cylinder and
piston will cause binding, rapid wear of packing and
packing gland, rapid wear of piston rod and packing, and
tend to break the weld on the cylinder case. The welded
section is designed to hold hydraulic pressure and
4-6
e. Reassembly.
(1) Assemble tilt cylinder in reverse order of
procedures in disassembly (c above), with the addition of
the following:
(a) Dip all packings, gaskets, and wiper
rings in hydraulic oil before assembly.
(b) Oil piston parts, plunger rod, and
packing nut before installation.
(c) When installing packing (6) on guide
ring (15), do not stretch packing any more than
absolutely necessary.
(d) Do not expand backup washers any
more than necessary.
CAUTION
Never use sharp tools or instruments
when installing rings, packings, or
backup washers.
(e) Torque nut (3) to 300 foot-pounds,
and install cotter pin (4).
(f) Tighten packing nut securely, then
back off approximately 1/8 turn.
(2) Be certain that all parts are kept clean
during installation and that no dirt or water is allowed to
enter the cylinder before the hydraulic lines are
connected.
f. Installation. Install the tilt cylinder by reversing
the procedure in paragraph 2-12.
(3) Unscrew packing nut (24) from retainer
(22).
(4) Remove screw (23) from retainer (22) and
unscrew retainer from tube assembly.
(5) Grasp rod (16) and pull all internal parts
(assembled) from tube assembly.
(6) Remove cotter pin (4) and nut (3) from
rod (16).
(7) Disassemble remainder of parts in order
shown.
d. Cleaning and Inspection.
(1) Clean all metal parts with solvent and dry
thoroughly.
(2) Check cylinder tube bore for scores or
nicks.
(3) Check sliding surfaces of guide ring (5)
and follower (12) for scores, nicks, or other irregularities
which could damage cylinder tube bore.
(4) Check bores of guide ring (5), follower
(12), and packing nut (24) and mating surfaces of
plunger rod (16) for damage which could cause faulty
seating, leaks, or damage to other parts.
(5) Check all backup rings and hardware for
cracks, bends, deformation, stripped threads, and other
damage.
(6) If mating or sliding surfaces are damaged
the parts must be replaced.
(7) Replace all packings, guard rings, and
wiper rings.
4-7
1 Pivot shaft
2 Tube assembly
3 Nut
4 Cotter pin
5 Guide ring
6 Packing
7 Backup ring
8 Packing
9 Packing cup
10 Backup ring
11 Packing
12 Follower
13 Screw
14 Lockwasher
15 Retainer
16 Plunger rod
17 Stuffing box
18 Packing set
19 Adapter
20 Ring
21 Packing
22 Retainer
23 Screw
24 Packing nut
25 Cotter pin
26 Flat washer
27 Yoke
28 Cotter pin
29 yoke pin
30 Wiper
Figure 4-4. Tilt cylinder.
(3) Remove bleeder screw from cylinder case,
and insert airhose. With lift control valve held in down
(forward) position, blow oil out of cylinder back into
reservoir.
(4) Disconnect hydraulic lines at lift cylinder.
(5) Wrap chain securely around outer case of
cylinder assembly below lift chain anchor flanges.
Attach hoist to chain and take up slack.
(6) Remove 2 screws attaching plunger to
roller support on inner mast.
(7) Lift cylinder assembly gently, to clear both
upper and lower ends of cylinder from mast assembly,
and remove.
4-6. Lift Cylinder
a. Description. The lift cylinder is a piston type
cylinder assembly. The plunger is bolted to the roller
support in the inner mast. The chain sprockets are also
mounted on this roller support.
In operation, the plunger is moved upward by force of
hydraulic pressure at the plunger base, raising the
inner mast and carriage.
b. Removal.
(1) Lower fork carriage, and remove carriage
backrest (para 4-8).
(2) Detach chains from cylinder TM 103930618-20.
4-8
CAUTION
Be careful not to damage cylinder
assembly when removing it from
mast assembly.
c. Disassembly.
Refer to figure 4-5 and
disassemble as follows:
(1) Using a spanner wrench, remove gland
nut (2) and wiper (11).
(2) Close off bleeder port, insert airhose in
1/2inch port and use compressed air to force packing (3)
and packing set (10) from tube assembly (5).
(3) Remove tube assembly (13) (plunger) with
bearing (4), spacer (12), and stop ring (11).
(4) Remove snapring (9) and restrictor parts
(6, 7, and 8).
d. Cleaning and Inspection.
(1) Clean all metal parts in SD.
(2) Examine wearing surfaces of tube
assemblies (5 and 13) for damage and evidence of
misalignment.
(3) Examine packings and wiper (1) for
scores, folded edges, and worn or torn sections.
Existence of these conditions indicates excessive
pressure or a loose gland nut (2)
(4) Inspect spring (7) for bent or stretched
condition.
(5) Replace parts as necessary.
e. Assembly. Reverse procedures in c above.
f. Installation.
(1) Reverse procedures in b above.
CAUTION
Be certain that all parts are clean and
that there is no foreign matter in the
cylinder tube.
(2) When cylinder has been installed, run lift
to extreme upper limit then open bleeder screw one or
two turns. Allow trapped air and foamy oil to run out.
When a clear stream of oil appears, tighten bleeder
screw.
1 Wiper
2 Gland nut
3 Packing
4 Bearing
5 Tube assembly
6 Washer
7 Spring
8 Spacer
9 Snapring
10 Packing set
11 Stop ring
12 Spacer
13 Tube assembly
Figure 4-5. Hydraulic lift cylinder.
4-9
Section III. REPAIR OF LIFT MAST
(3) Remove carriage assembly by sliding out
of mast channel.
(4) Remove wear strips (3 and 20)
as
necessary.
(5) Remove retaining rings (18) and remove
bearings (17) from inner masts.
(6) Remove retainer (9) and remove roller(8)
from roller support (7).
d. Inspection.
(1) Inspect mast channels for misalignment,
broken welds, excessive wear, worn or damaged wear
plates.
(2) Inspect bearings for excessive or uneven
wear. Check the pivot bushing (35).
(3) Repair cracks and minor breaks in mast
frames by welding if practical, and provided heat
distortion is avoided.
(4) Replace defective parts.
e. Assembly. Reverse procedures in c above.
f. Installation. Reverse procedures in b above.
4-7. Hydraulic Lift Mast
a. Description. The hydraulic lift mass, consists of
inner and outer masts with wear plates in the sliding
channels to provide maximum ease of movement.
b. Removal. Refer to figure 4-6 and remove as
follows:
(1) Remove lift forks (TM 10-3930-618-20).
(2) Remove hydraulic lift cylinder (para 4-7).
(3) Detach tilt cylinders from mast brackets
and remove lift chains (TM 10-3930-618-20).
(4) Attach chain hoist to lifting eyes on back of
outer mast and raise mast assembly enough to take
weight off pivot pins (34).
(5) Remove lock wires capscrews (37).
Remove capscrews, lockwashers (38) and
remove
pivot pins.
(6) Lift mast assembly free of truck.
c. Disassembly.
(1) Lay mast assembly on suitable support.
(2) Slide inner mast out of outer mast.
4-10
1 Outer mast
2 Shim
3 Wear strip
4 Capscrew
5 Capscrew
6 Chain guard
7 Roller support
8 Roller
9 Retainer
10 Screw
11 Lubrication fitting
12 Chain assembly
13 Inner mast
14 Capscrew
15 Lockwasher
16 Block
17 Bearing
18 Retaining ring
19 Shim
20 Wear strip
21 Capscrew
22 Lockwasher
23 Locknut
24 Adjusting nut
25 Chain anchor
26 Connecting link
27 Cotter pin
28 Tube
29 Elbow assembly
30 Lift cylinder
31 Retainer bar
32 Capscrew
33 Lockwasher
34 Pivot pin
35 Bushing
36 Cotter pin
37 Capscrew
38 Lockwasher
39 Nut
40 Lockwasher
Figure 4-6. Hydraulic lift mast.
4-11
(2) Remove retaining rings (7) and bearings
(8) from studs.
(3) If necessary, studs may be removed and
replaced by welding.
d. Inspection.
(1) Inspect backrest for cracked or broken
welds, and any wear or bends which could interfere with
heavy use.
(2) Inspect carriage far cracked or broken
welds, wear, bends, misalignment of the vertical bars, or
other damage.
(3) Inspect stud, bearing, and plug assembly
for misalignment, cracks or breaks, and excess wear.
(4) Repair damaged parts by welding if
practical.
(5) Replace defective parts.
e. Assembly. Assembly and installation are the
reverse of the procedures for disassembly and removal
in b and c.
4-8. Carriage and Backrest
a. Description. The fork lift carriage is a welded
assembly having horizontal upper and lower fork support
bars and a pair of vertical carriage support bars (fig. 47). The vertical bars each carry upper and lower stud
and bearing assemblies which ride in the channel of the
inner mast. The backrest is a welded metal frame, which
is attached to the upper fork support bar of the carriage
and serves to prevent loads from resting against the
mast when the mast is tilted back.
b. Removal.
(1) Support backrest with hoist, remove
capscrews (1) and lift backrest free of carriage.
(2) Disconnect lift chain at connecting link at
back of carriage.
(3) Remove carriage from mast by raising out
of mast channel.
c. Disassembly.
(1) Remove plugs (6) and screws (5).
4-12
1 Capscrew
2 Lockwasher
3 Backrest
4 Carriage frame
5 12-point screw
6 Plug
7 Retaining ring
8 Roller bearing
9 Screw, socket hd.
10 Lockwasher
11 Block
12 Shim
Figure 4-7. Hydraulic lift carriage and backrest.
4-13
CHAPTER 5
REPAIR OF FRONT AND REAR AXLE ASSEMBLIES
Section I. REPAIR OF STEERING SYSTEM
(5) Remove bolts securing upper steering
column support to truck frame.
(6) Disconnect hydraulic lines to steering unit.
5-1. Description
The power steering system consists of a steering gear
assembly, power steering cylinder, and a steering axle
assembly. Major components of the steering gear
assembly are a wheel and shaft and control unit. When
the steering wheel and shaft are turned, hydraulic fluid is
ported from the control assembly, through hoses, to
either the front or rear of the power steering cylinder.
NOTE
Tag hydraulic lines and steering unit
fitting for identification.
Plug
hydraulic
lines
immediately
to
prevent loss of fluid or entrance of
foreign material.
5-2. Steering Gear Assembly
(7) Lift steering gear assembly with mounting
support up and out of truck and place it in a clean work
area for disassembly. Clean all paint and surface
contamination from unit at points of separation.
b. Disassembly and Reassembly.
(1) Refer to paragraph 5-6 for removal and
installation of the shifting lever mechanism.
(2) Refer to figure 5-2 and disassemble the
steering assembly to the degree required for repair.
Reassemble in the reverse order.
a. Removal and Installation. Refer to figure 5-1 to
remove or install steering column, bracket, and steering
unit as an assembly.
(1) Remove floor and toe plates (TM 103930618-20).
(2) Disconnect shift linkage.
(3) Disconnect neutral switch and horn wires.
(4) Remove bolts that secure steering gear
mounting bracket to truck frame.
5-1
A. Steering column support.
Figure 5-1. Steering gear assembly removal and installation (sheet 1 of 2).
5-2
B. Steering unit bracket.
Figure 5-1. Steering gear assembly removal and installation (sheet 2 of 2).
5-3
1 Horn cover
2 Horn button
3 Contact cup
4 Spring
5 Contact cap
6 Base plate
7 Screw
8 Spring
9 Contact washer
10 Nut
11 Lockwasher
12 Steering wheel
13 Connector
14 Screw
15 Brush assembly
16 Oil seal
17 Plate
18 Bolt
19 Screw
20 End cap
21 Rotor
22 End plate
23 Drive
24 Seal
25 Ferrule
26 Contact spring
27 Contact washer
28 Retaining ring
29 Retaining ring
30 Bearing
31 Retaining ring
32 Shaft
33 Wire assembly
34 Contact ring
35 Insulator
36 Column
37 Bolt
38 Control assembly
39 Bushing
40 Packing
41 Pin
42 Spring
43 Packing
44 Plug
45 Seat
46 Ball
47 Spring
48 Housing
49 Control sleeve
50 Control spool
Figure 5-2. Steering gear assembly.
5-4
c. Reassembly.
(1) Note match-marks on column (36) and
secure column to mounting plate (17) with bolts (37).
Torque bolts to 280 inch-pounds.
(2) Install retaining ring (31), bearing (30), and
retaining ring (26) on shaft (32).
(3) Insert horn wire (33) through washer (27),
spring, ferrule (25), and partially through shaft (32).
Bring wire out from shaft and attach to contact ring (34).
(4) Insert insulator (35) in contact ring (34)
and slide both, gradually pulling back on horn wire, on
shaft (32).
(5) Insert shaft (32) in column (36) and secure
with retaining ring (28). Rotate shaft to engage shaft and
spool splines.
(6) Install brush assembly (15) on column (36)
securing with screws (14).
(7) Install connector (13) on brush wire.
(8) Install steering gear support bracket on
steering column and secure it to steering gear with two
screws (37) and lockwashers.
5-5. Steering Unit a. Removal.
(1) Refer to paragraph 5-2 for steering gear
assembly removal.
(2) Refer to paragraph 5-4 a (7) for separation
of steering unit from steering column.
b. Disassembly.
(1) Clamp end plate (17) of steering unit
assembly in vise with end cap (20) up and remove
screws (19).
(2) Remove end cap (20), rotor (21), plate
(22) and drive (23) from control assembly housing (48).
c. Control Spool Rotation Check. Remove control
assembly (38) from vise and check for free rotation of
control spool (50) and sleeve (49) using shaft (32) (fig. 5-3
3).
5-3. Horn Button and Steering Wheel
a. Removal.
(1) Push down on horn button cover (1, fig.
5-2) and turn to right.
(2) Remove horn button cover (1), button (2),
contact cup (3), spring (4), and contact cap (5).
(3) Separate horn button wire (33) from base
plate (6).
(4) Remove screws (7) from base plate (6)
and remove base plate, contact spring (8) and contact
washer (9).
(5) Remove steering wheel nut (10) and
lockwasher (11) from steering shaft (32).
(6) Using wheel puller, remove steering wheel
(12) from shaft (32).
(7) Remove two screws (37) and lockwashers
attaching steering gear support bracket to steering gear
assembly.
b. Installation.
(1) Thread horn wire (33, fig. 5-2) through
steering wheel (12), lockwasher (11), nut (10), washer
(91, and spring 18) and attach wire to base plate (6).
(2)
Press steering wheel (12) on
shaft and secure with lockwasher (11) and nut (10).
(3)
Install base plate (6) and secure
with screws (7) making sure horn wire (33) is securely
attached to plate.
(4)
Install cap (5), spring (4), cup (3)
and button (2) on base plate (6).
(5)
Install horn button cover (1) by
pressing down on cover and turning right.
5-4. Column a. Removal.
(1) Refer to paragraph 5-2 for steering gear
assembly removal and installation.
(2) Refer to paragraph 5-3 for steering wheel
and horn button removal.
b. Disassembly.
(1) Remove screws (14, fig. 5-2), brush
assembly (15), and contactor (13) from column (36).
(2) Working through brush plate opening,
disconnect horn wire (33) from contact ring (34).
(3) Remove horn wire (33), ferrule (25), spring
(26), and washer (27) by slowly pulling wire from shaft
(32).
(4) Remove retaining ring (28) from column
(36) and slide shaft and bearing from column (36).
(5) Remove bearing retaining ring (29), press
off bearing (30), and remove other bearing retaining ring
(31) from shaft (32).
(6) Mark two bolt hole locations on column, so
that ports will be correctly referenced when unit is
reassembled.
(7) Remove column bolts (37) and column
(36) from mounting plate (17).
Figure 5-3. Checking control spool rotation.
5-5
d. Mounting Plate.
(1) Place wooden block across vise throat to
support spool parts.
(2) Clamp control assembly (38, fig. 5-2)
across port face with control end up and remove
mounting plate attaching bolts (18).
(3) Hold spool assembly down
against
wooden block and lift off mounting plate (17).(4)Inspect
mating surfaces for obvious leakage path and wear.
Remove and discard quad ring shaft seal (24) and oil
seal (16) in mounting plate (17).
e. Control Assembly.
(1) Remove cap locator bushing (39) and
packing (40) Discard packing.
CAUTION
Use extreme care when removing
control spool and sleeve, as they are
very closely fitted and must be
rotated
slightly
as
they
are
withdrawn.
(2) Place port face of housing (48) on a solid
surface and remove control spool and sleeve from 14hole end of housing.
CAUTION
Do not pry against edge of hole in
housing bore.
(3) Using a small bent tool or wire, remove
check valve seal plug (44) from housing (48) by reaching
it through "out" port and pushing upwards (fig. 5-4).
Remove and discard packing (43, fig. 5-2).
(4) With housing in vise control end up,
unscrew check seat (45) with 3/ 16 inch hex wrench.
(5) Remove housing from vise and up end it.
Tapping it lightly with palm of hand, allow check valve
seat (45) ball (46) and spring (47) to fall into other
hand.
(6) Remove centering pin (41) from control
spool and sleeve.
(7) Push inside lower edge of spool (50) so
that spool moves toward splined end and remove spool
carefully from sleeves (49).
(8) Push the centering spring set (42) out of
spring slot in spool (50).
Figure 5-4. Removing check valve seal plug.
f. Cleaning, Inspection, and Repair.
(1) Clean all parts with cleaning compound,
solvent (P-S-661).
Cleaning may be done during
disassembly and parts set to dry on clean paper towel.
(2) Inspect all moving parts to make sure they
have not been scored or damaged by dirt particles.
Smooth burnished surfaces are normal in many areas.
Any slightly scored parts may be cleaned by hand
rubbing with 600-grit abrasive paper.
(3) Prepare all surfaces of control assembly
for assembly as follows:
(a) Place a piece of 600-grit abrasive
paper face up on a piece of plate glass or similar
material.
(b) Clean the ends of the star gear first
to remove any sharp grit from the paper which could
produce scratches.
(c) Clean both sides of the ring gear,
both sides of the plate, the 14-hole end of the housing,
and the flat side of the end cap.
5-6
(d) Stroke each surface across the
abrasive several times and check the results. Any small
bright areas indicate a burr which must be removed.
When polishing the parts, hold them as flat as possible
against the abrasive. After 6-to-10 strokes across the
abrasive, check the part to see if it is polished. After
each part is polished, rinse clean in solvent’, blow dry
with air, and place it where it can remain absolutely clean
until assembly.
(4) Replace all packing and oil seals.
Replace all other parts as authorized.
g. Assembly and Adjustment.
(1) General. Refer to figures 5-2 thru 5-6
when assembling and adjusting.
(2) Control assembly.
(a) Install clean wooden block in vise to
provide platform for assembly operations.
(b) Place housing (48) on wood
platform and drop check valve spring (47) into check
hole with large end down.
(c) Drop check ball (46) into check hole
making sure it rests on top of small end of spring (47).
(d) Place check valve seat (45) on
3/16inch hex wrench and screw into a check hole so
machined counterbore of seat is towards ball (46).
(e) Lower wood platform in vise and
place housing (48) on platform control end up. Clamp
vise jaws lightly across housing port surface.
(f) Torque seat (45) to 150 inch-pounds
and test ball (46) action by pushing against it with small,
clean pin.
NOTE
Ball need not be snug against seat to
function properly.
(g) Carefully install the spool (50) into
the sleeve (49). Be sure that spring slots of both spool
and sleeve are at the same end. Rotate spool carefully
while sliding parts together. Test for free rotation.
CAUTION
Spool must rotate smoothly in sleeve
with finger tip force applied at splined
end.
(h) Clamp wooden platform in jaws, set
control spool and sleeve on platform and aline spring
slots of both.
(i) Stand control spool and sleeve on
end and insert a flat tool through slots or both parts.
(j) Position three pairs of centering
springs (42), or two sets of three each, on bench so
extended edge is down and center section is together.
(k) Install one end of positioned spring
set (42) on flat tool. Compress extended end of spring
set and push it into control spool and sleeve, withdrawing
flat tool at same time. See figure 5-5.
Figure 5-5. Installing centering spring set.
(I) Center spring set (42), alining each
spring so the entire set is flush with upper surface of
control spool and sleeve.
(m) Install the cross pin (41) through the
spool and sleeve and push into place until pin is flush or
slightly below the sleeve diameter at both ends.
(n) Place the housing (48) on a solid
surface with the port face down. Install the spool
assembly with the splined end of the spool (50) entering
the 14-hole end of the housing first. Push parts gently
into place with a slight rotating motion.
CAUTION
Use extreme care so control
assembly (38) does not lose alinement
when entering housing (48).
(o) Install control assembly (38) in
housing bore until flush with 14-hole end of housing.
CAUTION
Do not pull control assembly beyond
flush position or cross pin (41)will
drop into housing discharge groove.
(p) Turn splined end of control
assembly (38), checking for free rotation.
(q) Install new packing (43) and check
plug (44) in check plug hole. Use steady pressure on
plug and rock it slightly so packing feeds in smoothly
without cutting.
(r) Install new packing (40) and seal
(24) on spool (50).
(s) Seat cap locator bushing (39), large
outside diameter up, against spool (50) evenly.
h. Mounting Plate.
(1) Check mounting plate seal grooves for
cleanliness and smooth condition.
(2) Install and smooth down new quad ring
shaft seal (24) and oil seal (16) into mounting plate (17)
seal grooves.
5-7
(6) Push splined end of drive (23) through the
gear until spline extends about one-half its length beyond
gear star. Hold it in this position while installing it in the
unit. Note position or direction of cross pin (41) within
the unit.
(7) Install gear-drive assembly into rotor ring
(21), drive (23) first, and slowly rotate it to engage cross
slot in drive (23) with cross pin (41). Splined end of drive
will drop down against rotor ring (21) when slot engages.
CAUTION
Alinement of the cross slot in the
drive with the valleys between the
teeth of the gear star determines the
proper valve timing of the unit. There
are 12 teeth on the spline and 6 on
the star. Alinement will be right in 6
positions and wrong in 6 positions.
Should the parts slip out of position
during this part of the assembly,
make certain that proper alinement is
obtained.
(8) Place end cap (20) over assembly and
install screws (19) finger tight, to maintain alinement of
parts.
(9) Secure assembly in vise and torque
screws to 150 inch-pounds.
j. Installation.
(1) Install steering gear and secure steering
gear support (22, fig. 5-2) in place on truck bracket with
flat washers (23), lockwashers (24), and screws (25).
(2) Install clip on upper part of column (36, fig.
5-2).
(3) Connect brush assembly connector (13).
(4) Note identification marks on hydraulic
hoses and attach hoses to proper ports in control
housing (48).
(5) Install floor and toe plates (TM 103930618-20).
5-6. Shifting Mechanism
a. Removal.
(1) Remove floor plate (TM 10-3920-618-20)
and steering wheel (para 5-3).
(2) Remove roll pin (4, fig. 5-7) holding
indicator (3) in position and move indicator up shaft.
(3) Remove capscrews (1) holding cover (5)
in place and move out of way.
(4)
Remove capscrews from steering
column support (19) and the two mounting brackets (8
and 27).
NOTE
Oil seal (16) lip must face away from unit
(3) Place the mounting plate subassembly
over the spool shaft and slide it down smoothly in place
over the cap locator bushing (39) so that seals will not be
damaged.
(4) Aline the bolt holes in the cover (17) with
the tapped holes in the housing 1481. Be sure the
mounting plate’ rests fairly flush against end of housing
assembly so that the cap locator bushing is not cocked.
(5) Install mounting plate attaching bolts (18)
and torque each to 150 inch-pounds.
i. End Plate.
(1) Reposition control housing (48) in vise,
clamping the mounting plate with 14-hole surface up.
(2) Check that control spool and sleeve are
flush or slightly below 14-hole surface and that surface is
clean.
(3) Place end plate (22) over control spool
and sleeve, alining bolt holes in plate with tapped holes
in housing 1481.
(4) Place rotor ring (21) on assembly and
aline bolt holes.
(5) Place splined end of drive (23) in rotor
gear star so slot at control end of drive is alined with
outside diameter valleys of gear. See figure 5-6.
Figure 5-6. Drive-gear alinement.
5-8
(5) Loosen actuating lever capscrew (40).
(6) Detach shifting rod ball joint (31) from shift lever (30).
(7) Lift mechanism out of truck.
(8) Shift lever can now be removed by removing pin (29).
b. Cleaning and Inspection.
(1) Clean all parts in SD and dry.
(2) Inspect all parts for excess wear, deformation, cracks, stripped threads, and other damage.
(3) Replace defective parts as authorized.
c. Installation. Install in reverse order of removal.
d. Adjustment.
(1) If shifting mechanism binds, check alignment at mounting bracket (8) on steering column and mounting
bracket (27).
(2) To obtain proper operation of the shifting mechanism it is important that the detent in the indicator plate be
synchronized with the detents in the selector valve plunger. Correct synchronization of the detents can be obtained by
adjusting the rod assembly (36) between the selector valve plunger and the lever (30).
(3) After shifting detents are correctly adjusted, the neutral switch (21) and lever (24) should be adjusted for
correct operation.
(4) To adjust, loosen capscrew (40) holding lever (24) to shifting rod (11) and, with the shifting mechanism in
neutral, move cam so that switch lever is at lowest point on cam, making sure switch is in OFF position.
(5) Tighten capscrew in switch lever. Move shifting lever (15) to either forward or reverse position, turn ignition
key to start. If engine does not start, adjustment is correctly made.
(5) Loosen actuating lever capscrew (40).
(6) Detach shifting rod ball joint (31) from shift
lever (30).
(7) Lift mechanism out of truck.
(8) Shift lever can now be removed by
removing pin (29).
b. Cleaning and Inspection.
(1) Clean all parts in SD and dry.
(2) Inspect all parts for excess wear,
deformation, cracks, stripped threads, and other
damage.
(3) Replace defective parts as authorized.
c. Installation. Install in reverse order of removal.
d. Adjustment.
(1) If shifting mechanism binds, check
alignment at mounting bracket (8) on steering column
and mounting bracket (27).
(2) To obtain proper operation of the shifting
mechanism it is important that the detent in the indicator
plate be synchronized with the detents in the selector
valve plunger. Correct synchronization of the detents
can be obtained by adjusting the rod assembly (36)
between the selector valve plunger and the lever (30).
(3) After shifting detents are correctly
adjusted, the neutral switch (21) and lever (24) should be
adjusted for correct operation.
(4) To adjust, loosen capscrew (40) holding
lever (24) to shifting rod (11) and, with the shifting
mechanism in neutral, move cam so that switch lever is
at lowest point on cam, making sure switch is in OFF
position.
(5) Tighten capscrew in switch lever. Move
shifting lever (15) to either forward or reverse position,
turn ignition key to start. If engine does not start,
adjustment is correctly made.
1 Screw
2 Lockwasher
3 Indicator
4 Pin
5 Cover
6 Lockwasher
7 Screw
8 Bracket
9 Ball
10 Bushing
11 Rod
12 Spring
13 Stop
14 Pin
15 Shifting lever
16 Knob
17 Screw
18 Clip
19 Support assembly
20 Wire
21 Switch
22 Lockwasher
23 Nut
24 Lever
25 Lockwasher
26 Nut
27 Bracket assembly
28 Bushing
29 Pin
30 Lever
31 Joint
32 Nut
33 Bracket assembly
34 Washer
35 Screw
36 Rod
37 Yoke
38 Pin
39 Cotter pin
40 Screw
Figure 5-7. Forward-reverse assembly.
5-9
(4) Tap out seat (29) and spring (28) from
link. Remove elbows (5) from tube assembly (10).
(5) Remove lockring (14) holding spacer (15)
in position and remove spacer.
(6) Compress lockring (16) holding head (19)
cylinder assembly (10) and remove actuating rod (12)
with remaining components attached from cylinder
assembly (10).
(7) Carefully slide head (19) off rod (12) end
and remove head seal (20), wiper (13), backup washer
(17), and packing (18) from head. Discard packing.
(8) Remove nut (21) securing piston (24) to
rod end and slide piston off rod.
(9) Remove two backup washers (22) and
packing (23) from piston (24). Discard packing.
(10) Remove rod seal (25) from rod (12).
(11) Check bearing (27) and lubrication fitting
(26) at tube end. If damaged, replace parts. Press
bearing from cylinder to remove.
5-7. Power Steering Cylinder
a. Description.
When hydraulic oil is under
regulated pressure from the steering gear and enters the
power steering cylinder, the piston moves forward or
back within a tube, depending on which side of the piston
hydraulic fluid is forced. The movement of the piston
rod, with attached yoke, moves the steering axle pivot
arm and attached tie rods.
b. Removal.
Refer to TM 10-3930-618-20 for removal procedure.
c. Disassembly.
(1) Refer to figure 5-8 and disassemble as
follows:
(2) Remove cotter pin (1) and adjusting plug
(30) from end of steering link (3).
(3) Remove lubrication fitting (2) and plug (31)
from steering link and remove link and nut (4) from rod
(12).
Key to figure 5-8.
1 Cotter pin
2 Lubrication fitting
3 Link
4 Nut
5 Elbow
6 Pin
7 Lockwasher
8 Screw
9 Spacer
10 Cylinder assembly
11 Cylinder
12 Rod
13 Wiper
14 Lockring
15 Spacer
16 Lockring
17 Backup washer
18 Packing
19 Head
20 Head seal
21 Nut
22 Backup washer
23 Packing
24 Piston
25 Seal
26 Lubrication fitting
27 Bearing
28 Spring
29 Ball seat
30 Plug
31 Plug
5-10
Figure 5-8. Power steering cylinder with yoke.
5-11
d. Cleaning and Inspection.
(1) Clean all parts with cleaning compound,
solvent (Spec. P-S-661).
(2) Inspect tube bore, rod head, and piston for
cracks, scratches, scoring, and other damage. Repair or
replace damaged components.
(3) Prior to assembly, coat all components
with clean hydraulic oil to aid in installation and provide
initial lubrication.
(4) Replace all seals and packing.
e. Assembly.
(1) Refer to figure 5-8 and assemble as
follows:
CAUTION
Be careful not to damage seals and
packing during assembly.
(2) Install rod seal (25) on rod (12).
(3) Position backup washers (22) and packing
(23) on piston (24).
(4) Install piston (24) on rod (12) and secure
with nut (21).
(5) Install packing (18), backup washer (17),
and wiper (13) in head (19).
(6) Position head seal (20), lockring (16),
spacer (151, and lockring (14) on head (19).
(7) Carefully slide piston and rod assembly
into cylinder (11).
(8) Position head assembly over rod (12) and
compress lockring (16).
(9) With lockring (16) compressed, head
assembly into cylinder until lockring snaps into tube
groove.
(10) Install elbows (5) in cylinder.
(11) Install spring (28), seat (29), and adjusting
plug (30) in link (3).
(12) Install nut (4) and link (3) on rod (12).
(13) Install lubrication fitting (2), plug (31), and
cotter pin (1) in link (3).
(14) If bearing (27) was removed, press new
bearing into bore at end of cylinder (11).
f. Installation and Adjustment. Refer to TM 10-3930618-20 for installation and adjustment procedure.
5-8. Steering Axle and Wheels
a. Description. The cruciform - trunnion mounted
steering axle is mounted in lubricated self-aligning sleeve
bearings. A hydraulic operated control unit pivots an arm
that moves tie rods connected to the spindles on which
the steering wheels are mounted.
b. Removal. Refer to paragraph 2-14 for removal
of the steering axle and wheels from the truck.
5-9. Steer Wheel Bearings
a. Removal. If steering axle has not been removed
from the truck proceed as follows:
(1) Raise the rear of the truck until the wheels
clear the floor. Block front wheels securely to prevent
truck from rolling.
(2) Remove the hubcaps (3, fig. 5-9).
(3) Remove the cotter pin (4); from the
bearing adjusting nut (5) and remove the nuts and
washers.
(4) Remove the outer bearing cone (7).
(5) Slide the hub assembly (9) from the
steering axle spindle.
(6) Remove the inner bearing cone (11) and
grease retainer (12) from the hub assembly.
(7) Carefully tap both bearing cups (8, 1.0)
from the hub assembly.
b. Cleaning, Inspection and Repair.
(1) Clean all parts with cleaning compound,
solvent (Spec.
P-S-661).
Dry thoroughly with
compressed air.
(2) Inspect bearing cones and cups and
wheels for damage and excessive or uneven wear.
(3) Replace all parts as authorized.
(4) Repack bearings (TM 10-3930-618-20).
c. Installation and Adjustment.
(1) Install bearing cups with the taper to the
inside. Tap into place using a brass drift pin. Tap evenly
around the edge of the cup. Use care to prevent the cup
from binding.
(2) Install the bearing cones and hub
assemblies in reverse order of removal. Hold the hub
assemblies in position while installing the outer bearings.
(3) Install the adjusting nut(s) and washer.
(4) Tighten the adjusting nut and, at the same
time, rotate the wheel until a heavy drag is felt.
(5) Loosen the nut to the point where the
wheel rotates freely but no bearing end play is apparent.
(6) Install cotter pin (4) in the wheel nut and
reinstall the hubcap (3).
5-12
1 Screw
2 Washer
3 Cap
4 Pin
5 Nut
6 Washer
7 Cone-rollers
8 Cup
9 Hub
10 Cup
11 Cone-rollers
12 Seal
Figure 5-9. Steer wheel and bearings, removal and installation.
(2) Remove spacers (4) and self-aligning
bearings (3) from housings.
(3) Remove lubrication fittings from top of
housing.
e. Remove pivot arm (22) from steering axle (8) as
follows:
(1) Remove nut (13),washer (12) and bearing
cone (11).
(2) Remove pivot arm (22) from axle and
bearing cup (20) and bearing cone (21) from pivot arm
(22).
(3) Remove bearing cups (10 and 20) and
retaining ring (9) from axle if replacement is necessary.
(4) Remove lubrication fitting.
f. Remove king pins (18) and spindles (1 and 15)
as follows:
(1) Remove expansion plugs.
(2) Remove pins (16) and tap pins (18) from
spindles (1 and 15).
(3) Remove spindles (1 and 15) from axle.
Remove four thrust washers (17).
(4) Press out needle bearings (14) from axle.
(5) Remove lubrication fittings.
5-10. Steering Axle and Tie Rods
a. Removal. Refer to paragraph 2-14 for removal
of the steering axle from the truck.
b. Disassembly.
Refer to figure 5-10 and
disassemble the axle as follows:
c. Remove and disassemble the tie rods as follows:
(1) Remove cotter pin, nut, and flat washer
from bottom of tie rod end (24).
(2) Remove cotter pin and loosen adjusting
plug (30).
(3) Remove tie rod (2 and 26).
(4) Remove adjusting plug (30), ball seat (29),
and spring (28) from tie rods.
(5 ) Slip cover (23) from tie rod end (24).
(6) Loosen jam nut on tie rod end (24) and
remove tie rod end from tie rods.
(7) Remove lubrication fittings from rods and
rod end (24).
d. Disassemble bearing housing (6) as follows:
(1) Remove
screws,
lockwashers,
flat
washers and shims (5) from bearing housing (6). Tag
and count number of shims for correct installation.
5-13
1 Left spindle
2 Left tie rod
3 Self-aligning bearing
4 Spacer
5 Shim
6 Housing
7 Locknut
8 Axle
9 Retaining ring
10 Bearing cup
11 Bearing cone
12 Washer
13 Nut
14 Needle bearing
15 Right spindle
16 Spring pin
17 Thrust washer
18 King pin
19 Setscrew
20 Bearing cup
Figure 5-10. String axle and tie rods.
5-14
21 Bearing cone
22 Pivot arm
23 Cover
24 Tie rod end
25 Jam nut
26 Right tie rod
27 Safety plug
28 Spring
29 Seat
30 Adjusting plug
g. Cleaning and Inspection.
(1) Clean all parts with cleaning compound,
solvent (Spec. P-S-661).
(2) Inspect all moving parts, bearings, and
attaching parts for wear, corrosion, or other damage.
(3) Worn or deteriorated parts must be
replaced as authorized.
h. Assembly.
(1) Refer to figure 5-10 and assemble and
install as follows:
(2) Install king pins (18) and spindles (1 and
15) as follows:
(a) Install lubrication fittings and needle
bearings (14) in axle (8).
(b) Aline spindles (1 and 15) and thrust
washers (17) in axle and tap in king pins (18).
(c) Aline king pins (18) in spindle (1 and
15 ) and tap in pins ( 16) to secure king pins.
(d) Install expansion plugs.
(e) Lubricate assembly (TM 10-3930618-20).
i. Install pivot arm (22) in axle (8) as follows:
(1) Install lubrication fittings and pack
bearing cones (11 and 21) with grease (GAA).
(2) Install retaining ring (9) and bearing cups
(10 and 20) in axle (8), if they are removed.
(3) Press bearing cone (21) on pivot arm (22).
(4) Install pivot arm (22) in axle (8), firmly
seating bearing cone (21) in bearing cup (20).
(5) Press bearing cone (11) into bearing cup
(10) at bottom of axle.
(6) Slide washer (12) on pivot arm (22) and
secure assembly with nut (13). To preload bearings,
torque nut to 20-30 foot pounds. Stake nut to hold in
position.
(7) Lubricate cavity with grease (TM 10-3930618-20).
(8) Install lubrication fitting, self-aligning
bearings (3), and spacer (4) in housing (6).
(9) Lubricate housing (6) (TM 10-3930-61820).
j. Assemble and Install Tie Rods (2 and 26) as
follows:
(1) Install lubrication fittings on rods (2 and
26) and tie rod ends (24).
(2) Install tie rod ends in rods and tighten jam
nuts (25).
(3) Install covers (23) on tie rod ends.
(4) Install adjusting springs (28), ball seats
(29), and plugs (30) in tie rods.
(5) Install tie rods on spindles (1 and 15) and
pivot arm (22).
(6) Tighten adjusting plugs (30), then back off
enough so there is some end play. Then secure plugs
with cotter pins.
(7) Secure tie rod ends to axle with flat
washer, nuts, and cotter pins.
(8) Lubricate tie rod ends and rods (TM 103930-618-20).
k. Installation. Refer to paragraph 2-14 for steering
axle installation.
l. Adjustment.
If the steering system should
require adjustment, the following procedure should be
followed:
(1) Raise the rear end of the truck so that the
steer wheels clear the floor. Block in position.
(2) Disconnect the steer cylinder from the
pivot arm.
(3) Turn the steer wheels full right and full left.
Measure the distance between the wheel and the axle at
both wheels. Clearance should be at least 1/2 inch.
While holding this distance, adjust the spindle stops to
allow approximately 0.030 inch clearance between the
stop and the spindle (fig. 5-11).
(4) Center the steering gear.
Count the
number of turns of the steering wheel from extreme right
to extreme left, or vice-versa. Turn the steering wheel
back half this number of turns to its mid-position of
travel.
(5) Set the steer wheels straight ahead,
parallel with the sides of the truck frame. It may be
necessary to adjust the tie rods to obtain this position,
as zero degrees toe-in must be maintained at all times.
(6) With the steering gear centered and the
steer wheel correctly positioned, loosen the clamp bolt at
the plunger end of the steer cylinder and with an open
end wrench turn the plunger in or out of the clamp so
that the socket at the pivot arm end of the steering unit
will be correctly aligned with the ball on the pivot arm.
Screw in the plug and install the cotter pin. The steering
cylinder plunger will be half-way out of the cylinder.
(7) Start the engine and check the steering
system. With all adjustments correctly made, the wheel
spindles should contact the stop screws on the axle to
prevent the piston from bottoming in the steering
cylinder. This prevents excessive thrust and cramping of
the steering linkage and excessive relief valve operation.
5-15
Figure 5-11. Stop adjustment.
Section II. REPAIR OF BRAKE SYSTEM
(7) Remove screws (3) and lockwashers (2)
and remove backing plate (1) from pinion bearing cap.
5-11. General
The handbrake is a dual-shoe, mechanical-type and is
mounted to the differential pinion flange.
The
brakeshoes are actuated through a cable by an
adjustable, over-center type lever. The service brake
system contains a mechanically actuated hydraulic
master cylinder with an attached power booster. A heavy
duty brake line transmits hydraulic pressure from the
power booster to double-end type cylinders in each drive
wheel. The brakeshoes are the free floating type, and
are provided with major and minor adjustment cams,
accessible at the rear of the backing plates.
5-12. Handbrake Assembly
a. Removal. Refer to TM 10-3930-618-20.
b. Disassembly. Refer to figure 5-12 and proceed
as follows:
(1) Remove universal joint.
(2) Detach lower cable yoke from actuating
lever (5).
(3) Remove cotter pin (37, fig. 5-19) and
remove nut (38) from drive pinion shaft.
(4) Remove brakedrum (8, fig. 5-12).
(5) Remove springs (7) from brakeshoe
assemblies (6) and slide shoes from actuating pawls.
(6) Remove actuating lever (5) and rollers (4).
b. Inspection.
(1) Check backing plate for distortion, loose or
sheared rivets, and worn pawls.
(2) Check brake lining for abnormal wear or
grease saturation.
(3) Check brakeshoes for worn pawl holes,
lever contact areas or wear pads and cracks or
distortion.
(4) Check brakedrum for cracks, scoring, or
other damage.
(5) Replace drum if defective. If serviceable,
use fine emery cloth to remove discolorations and lining
residue from interior surfaces.
(6) Replace other defective parts as
authorized.
c. Reassembly and Installation.
(1) Reverse procedures in a above.
(2) Apply light coat of brake lubricant to wear
pads and pawls on backing plate and wear surfaces of
actuating lever and shoes.
(3) Refer to TM 10-3930-618-20 for
adjustment.
5-16
1 Backing plate
2 Lockwasher
3 Capscrew
4 Roller
5 Actuating lever
6 Shoe assembly
7 Spring
8 Brake drum
Figure 5-12. Hand brake assembly.
(2) Resurface drums if scored, cracked from
heat checks, or out-of-round.
Do not resurface
previously turned drums or turn in excess of 0.030 inch.
(3) If resurfacing drums is not required, polish
surface with fine emery cloth to remove discoloration and
lining residue.
(4) Inspect linings for abnormal wear and
brake fluid or grease saturation.
(5) Replace linings if worn to less than 1/8
inch or if saturated with brake fluid or grease.
(6) Inspect shoes for distortion and cracks.
(7) Inspect for weak or broken return springs.
c. Reassembly and Installation.
(1) Reverse procedures in a above.
(2) Refer to figure 5-13 for installation
instructions for the adjusting pawl.
CAUTION
Do not attempt to adjust this system
manually by using a wrench to turn
tack welded pawl nut.
(3) Brakes are self-adjusting and will maintain
a predetermined lining to drum clearance. Minimum
lining to drum clearance is established by width of the
adjusting pawl slots in the shoe webs. Lining to drum
clearance will be established with the first pedal
application.
5-13. Wheel Brake Assembly
a. Removal and Disassembly.
(1) Remove drive wheels (TM 10-3930-61820).
(2) Remove planetary gears, axle shafts,
hubs, and brakedrums (para 5-19).
(3) Remove shoe retaining spring (1, fig. 513, sheet 1 of 2).
(4) Remove the brake shoe return spring (2).
(5) Remove the brake shoe anti-rattle
components (3, 4, 5, and 7).
(6) Remove the brake shoes (6).
(7) Replace adjusting pawl assembly if spring
tension test is less than 107 lbs. (see fig. 5-13, sheet 2
of 2).
(8) Remove adjusting pawl (14) from backing
plate.
NOTE
It will be necessary to break tack weld to
remove adjusting pawl nut.
b. Inspection and Repair.
(1) Examine brake drums for scoring, heat
checks, or out-of-round condition.
5-17
1 Retaining spring
2 Return spring
3 Rod retainer
4 Spring
5 Rod retainer
6 Brake shoe
7 Anti-rattle rod
8 Capscrew
9 Lockwasher
10 Bleeder valve
11 Brake cylinder assy
12 Cylinder boot
13 Cup
14 Adjusting pawl
15 Nut
16 Lockwasher
17 Screw
18 Backing plate
Figure 5-13. Wheel brake assembly (sheet 1 of 2).
5-18
Figure 5-13. Wheel brake assembly (sheet 2 of 2).
5-14. Master Cylinder
a. Description. The brake master cylinder and fluid
reservoir are combined in one casting and are joined by
intake and bypass ports in the cylinder wall. Internal
parts are removable at the push rod end.
b. Removal. Refer to figure 5-14 and remove the
master cylinder assembly as follows:
(1) Remove the floor plate.
(2) Disconnect the electrical wires at the
stoplight switch.
(3) Remove the power booster (para 5-17).
(4) Remove the clevis pin holding the push
rod to the brake pedal.
(5) Remove the screws holding the master
cylinder assembly to the inside of the frame and remove
the cylinder.
Figure 5-14. Brake master cylinder installed view.
5-19
(1) Secure master cylinder in a vise, using
care not to crack or distort cylinder housing.
(2) Remove boot (2, fig. 5-15) and piston rod
(1).
(3) Hold piston in cylinder and remove lock
wire (3) by gentle prying.
CAUTION
When lock wire is removed, the entire
piston assembly will spring out if not
held in place.
(4) Carefully remove copper stop plate (4),
piston (5), piston cup (6), spring (7), and valve (8).
(5) Working from the other end of cylinder,
remove outlet fitting bolt (15), gasket (14), outlet fitting
(13), and gasket (12).
(6) Remove filler cap (11) and gasket (10).
d. Cleaning and Inspection.
(1) Clean all parts with denatured alcohol or
brake fluid, and keep clean in all following operations.
require honing to resurface the cylinder wall. Pressure
marks may be polished out with crocus cloth.
CAUTION
Do not use emery cloth or sandpaper.
(3) Make sure intake and bypass ports are
open. Bypass ports may e probed with soft iron wire.
(4) If it is necessary to resurface the cylinder
wall, follow the honing equipment manufacturers
recommendations. Do not hone cylinder oversize.
(5) Before assembly, inspect parts for
corrosion, scratched or pitted piston bearing surfaces,
rubber deterioration, and defective spring action.
Replace worn, damaged, corroded, or deteriorated parts
as authorized.
e. Assembly and Installation. Reverse procedures
in b and c above. Refer to TM 10-3930-618-20 for
hydraulic brake bleeding.
1 Piston rod
2 Boot
3 Lock wire
4 Stop plate
5 Piston assembly
6 Piston cup
7 Spring and retainer
8 Check valve
9 Cylinder and tank
10 Gasket
11 Filler plug
12 Gasket
13 Outlet fitting
14 Gasket
15 Fitting bolt
16 Lockwasher
17 Capscrew
18 Jamnut
19 Yoke
20 Yoke pin
21 Cotter pin
Figure 5-15. Master cylinder.
5-20
c. Disassembly.
(1) Remove nipple (2, fig. 5-17), bleeder
screw (1), and elbow (13).
(2) Clamp top end of booster in padded vise.
(3) Carefully unscrew lower part of housing
from upper part, using a pipe wrench.
(4) Grasp end of poppet (9) and carefully
withdraw poppet, sleeve (8), spring (4), and lower cup
washer (11) from lower part of housing.
(5) Remove spacer (6), cup washers (7 and
11), piston (10), and spring (12) from upper part of
housing.
d. Inspection and Repair.
(1) Inspect springs (4) and (2) for distortion or
stretching.
(2) Check poppet (9), sleeve (8), and piston
(10) for scratches, burs, and improper sliding fit.
(3) Inspect piston bore in upper housing for
scratches or out-of-round condition.
(4) Remove and discard packing (5).
e. Assembly. Reverse procedures in c above.
Make sure springs seat properly and no damage occurs
to housing. Replace packing (5).
f. Installation.
(1) Reverse procedures in b above.
(2) Use a suitable thread compound on thread
connections and make sure connections are tight.
(3) Bleed the brake system (TM 10-3930-61820).
5-15. Wheel Cylinders
a. Description.
The hydraulic wheel cylinder
houses two opposed pistons which actuate two opposed
brakeshoes. Pistons, rubber cups, and springs are held
in the cylinder by pressure from the brakeshoes. Open
ends of the cylinder are protected by rubber boots.
b. Removal.
(1) Remove brake assemblies (para 5-13).
(2) Disconnect brake line at cylinder fitting.
(3) Remove capscrew (8, fig. 5-13) and lockwashers (9) and remove cylinder from backing plate (18).
c. Disassembly.
(1) Remove rubber boots (12) from cylinder
ends.
(2) Push out internal parts.
d. Cleaning and Inspection.
Use the same
procedures for cleaning and inspection as those used for
the master cylinder (para 5-14). Replace defective parts
as authorized.
e. Assembly and Installation.
(1) Reverse procedures in b and c above.
(2) Refer to TM 10-3930-618-20 for bleeding
of brake system.
5-16. Brake Pedal
Refer to paragraph 3-17.
5-17. Power Booster
a. Description. The power booster is connected to
the master cylinder outlet through a pipe nipple and is
operated by pressure developed by the master cylinder.
The power booster multiplies this pressure and applies
the increased pressure to the wheel cylinders, resulting
in more positive braking.
b. Removal. Refer to figure 5-16 and remove the
power booster as follows:
(1) Remove the floor plate.
(2) Disconnect the brake line at the power
booster.
(3) Using an open-end wrench of the proper
size, turn the connecting nipple clockwise, into the
master cylinder, while holding the power booster. The
nipple will turn out of the power booster.
Figure 5-16. Brake power booster, installed valve.
5-21
1 Bleeder screw
2 Nipple
3 Booster assembly
4 Spring
5 Packing
6 Spacer
7 Cup washer
8 Sleeve
9 Poppet
10 Piston
11 Cup washer
12 Spring
13 Elbow
Figure 5-17. Power booster components.
Section III. REPAIR OF DRIVE AXLE
(2) Refer to paragraph 5-13 for service brake
5-18. Drive Axle Assembly
a. Description. The drive axle group consists of the
differential and carrier, axle shafts, and planetary geartype final drive. The drive wheel, bevel drive pinion, and
differential assembly are supported by tapered roller
bearings. The differential carrier is mounted at the
center of the drive axle housing. The differential consists
of two parts, the carrier assembly and case assembly.
The bevel ring gear is bolted to the differential case
which houses the spider and side gears. The pinion
gear is mounted in the differential carrier. Double
reduction is obtained by means of internal tooth
planetary gears mounted on the wheel hubs which are
driven through idler gears by pinion gears mounted at the
wheel ends of the axle shafts.
b. Removal. The complete drive unit, including wheels
and tires, can be removed as a unit (para 2-15).
5-19. Planetary Gears, Axle Shafts, Wheel Hubs, and
Brakedrums
a. Tire and Wheel Removal.
(1) Refer to TM 10-3930-618-20 for removal
of drive tires and wheels.
removal.
(3) Refer to paragraph 5-12 for hand brake
removal.
b. Disassembly.
(1) Rotate hubs until plug (18, fig. 5-18) in
cover (15) is at low point. Then remove plug and drain
oil from cover.
(2) Remove nuts (17) and lockwashers (16)
and pull cover (15), gear (11), and gaskets (10) from
studs in hub (25).
(3) Remove screws (14) and remove retainer
(12) from spider (1).
(4) Slide gears (9) and thrust washers (8)
from shafts (7).
(5) Insert threaded puller into tapped hole in
axle shaft (6) and carefully pull axle shaft from axle
housing tube (33).
(6) Remove nuts (4), lock (5), and washer (3)
from axle housing tube.
5-22
(7) Pull spider (1) from splines on axle
housing tube.
(8) Remove outer bearing cone (22) from hub
(25).
(9) Slide hub (25) and brakedrum (30) from
axle housing tube.
(10) Remove inner bearing cone (28) and oil
seal (29) from axle housing tube.
(11) Remove nuts (32) and lockwashers (31)
and separate hub from brakedrum.
(12) Remove bearing cups (21 and 27) from
hub only if replacement is necessary.
c. Inspection and Repair.
(1) Wash all metal parts in cleaning solvent
(P-S-661) and dry thoroughly.
(2) Inspect all gear teeth and splines for
excessive or uneven wear and damage.
(3) Inspect wheel bearings for defective
rollers, excessive radial play, and restricted rotation.
(4) Examine brake drums for scoring, heat
checks, or out of-round condition.
(5) Resurface drums if scored, cracked from
heat checks, or out-of-round.
Do not resurface
previously turned drums or turn in excess of 0.030 inch.
(6) If resurfacing drums is not required, polish
surface with fine emery cloth to remove discolorations
and lining residue.
(7) Inspect oil seal (29) for warping, damage,
or signs of leakage.
(8) Replace defective parts as authorized.
d. Reassembly and Installation.
NOTE
Do not reuse gaskets.
(1) Install wheel bearings, hub
(25),
brakedrum (30), and spider (1) on axle housing tube
(33).
(2) Install nuts (4), washer (3), and lock
bearings as follows:
(a) Rotate wheel in forward direction
and at the same time, tighten inner nut (4) until a definite
drag is felt in wheel rotation.
(b) Back nut off just to the point where
wheel rotates freely, then tighten outer nut against inner
nut without disturbing position of inner nut.
(3) Continue reassembly in reverse
order of disassembly ( b above). Use wooden or plastic
mallet to drive axle shaft in.
(4) Install wheel assemblies (TM 10-3930618-20).
(5) Lubricate in accordance with LO 10-3930618-12.
5-23
1 Spider
2 Spacer
3 Washer
4 Nut
5 Lock
6 Axle shaft
7 Shaft
8 Thrust washer
9 Pinion gear
10 Gasket
11 Internal gear
12 Retainer
13 Lockwasher
14 Screw
15 Cover
16 Lockwasher
17 Nut
18 Drain plug
19 Pipe plug
20 Stud
21 Bearing cup
22 Bearing cone, outer
23 Nut
24 Stud
25 Hub
26 Stud
27 Bearing cup, inner
28 Bearing cone, inner
29 Oil seal
30 Brakedrum
31 Lockwasher
32 Nut
33 Axle tube assembly
Figure 5-18. Drive axle assembly.
(3) Remove handbrake assembly if applicable
(TM 10-3930-618-20).
(4) Remove drain plug (15, fig. 5-19) and
drain oil from housing.
(5) Remove screws (34 and 39) and lockwashers (33 and 40) and slide bearing cap (31) and
gasket (29) off of pinion shaft, away from pinion cage
(28).
5-20. Drive Axle Housing and Differential
a. Removal and Disassembly.
(1) Remove drive axle assembly from truck
para 2-15).
(2) Remove wheels (TM 10-3930-618-20),
axle shafts (paras 5-19 b(1) through (5), and wheel rake
assemblies (para 5-13).
5-24
(6) Remove snapring (46) and remove
bearing (47) from bearing cap (31).
(7) Pull pinion shaft from differential housing.
(8) Remove screws (32 and 41), lockwashers
(5 and 30), and nut (6) and lift pinion cage (28) and
gasket (16) away from housing (7).
(9) Remove nuts (10) and lockwashers (11)
and pull axle housings (1 and 9) and gaskets (4) from
studs on drive housing (7).
(10) Support differential assembly and ring
gear in drive housing (7) and remove bearing cones (26)
and cups (25) from sides of housing.
(11) Carefully remove differential assembly and
ring gear from drive housing.
(12) Remove screws (43) and separate ring
gear from differential case (27).
(13) Remove lock wire (52) from screws (51);
remove screws and separate two parts of differential
case (27).
(14) Disassemble differential assembly (53) as
shown.
b. Inspection and Repair.
(1) Clean all metal parts in cleaning solvent PS-661 and dry thoroughly.
(2) Inspect bearings for worn rollers,
excessive radial play, and restricted rotation.
(3) Inspect gears for chipped, cracked, or
excessively worn teeth.
c. Reassembly and Installation.
(1) Reverse procedures in a above.
(2) Do not reuse gaskets.
(3) Lubricate in accordance with LO 10-3930618-12.
Figure 5-19. Drive axle housing and differential.
5-25
Key to figure 5-19.
1 Axle housing, rh
2 Oil seal
3 Stud
4 Gasket
5 Lockwasher
6 Nut
7 Final drive housing
8 Breather
9 Axle housing, rh
10 Nut
11 Lockwasher
12 Dowel pin
13 Screw
14 Level plug
15 Drain plug
16 Gasket
17 Nut
18 Lockwasher
19 Flat washer
20 Axle support
21 Saddle
22 U-bolt
23 Screw
24 Lockwasher
25 Bearing cup
26 Bearing cone
27 Differential case
28 Pinion cage
29 Gasket
30 Lockwasher
31 Bearing cap
32 Screw
33 Lockwasher
34 Screw
35 Oil seal
36 Hand brake assembly
37 Cotter pin
38 Nut
39 Screw
40 Lockwasher
41 Screw
42 Ring gear and pinion set
43 Screw
44 Lockring
45 Pinion bearing, rear
46 Snapring
47 Pinion bearing, front
48 Thrust washer
49 Thrust washer
50 Differential pinion gear
51 Screw
52 Lock wire
53 Differential assembly
54 Differential spider
55 Differential side gear
Section IV. REPAIR OF UNIVERSAL JOINT
remove screws (5) to separate cross assemblies (2)
from tube assembly (4).
(2) Break connecting plates tying trunnion
bearings together and remove trunnion bearings from
crosses.
d. Cleaning and Inspection.
(1) Clean all parts in cleaning solvent (Spec.
P-S-661) and dry thoroughly.
(2) Inspect bearing assemblies for freedom of
movement, and for excess wear or damage.
(3) Check cross assemblies, output flange,
and all capscrews for stripped threads and other dam
age.
(4) Replace defective parts as authorized.
e. Assembly. Reverse procedures in c above.
f. Installation. Reverse procedures in b above.
5-21. Universal Joint
a. Description. The universal joint assembly is of a
heavy duty industrial type consisting of two trunnion
bearing assemblies, a tube assembly (propeller shaft),
and an output flange. Very little service is normally
required of this assembly other than periodic repacking
of the bearings.
b. Removal. Refer to figure 5-20 and remove as
follows:
(1) Remove wires and capscrews (3) holding
cross assemblies (2) to the pinion shaft flange and
transmission output flange (1).
(2) Slide the output flange into transmission
and remove universal joint.
c. Disassembly.
(1) Bend back tabs on lock plates (6) and
5-26
1 Output flange
2 Crow assembly
3 Capscrew
4 Tube assembly
5 Screw
6 Lock plate
Figure 5-20. Universal joints.
5-27
APPENDIX A
REFERENCES
A-1. Lubrication
C9100IL
LO 10-3930-618-12
A-2. Painting
TM 9-213
A-3. Maintenance
TB 750-651
TM 38-750
TM 10-3920-618-34P
TM 10-3930-618-20
TM 10-3930-618-20P
TM 5-764
A-4. Shipment and Storage
TB 740-93-2
TM 740-90-1
A-5. Demolition
TM 750-244-3
Fuels, Lubricants, Oils and Waxes
Lubrication Order for Truck, Lift, Fork, AllisChalmers Model FP60-24PS
Painting Instructions for Field Use
Use of Antifreeze Solutions and Cleaning Compounds in Engine Cooling Systems
The Army Maintenance Management System
(TAMMS)
DS and GS and Depot Maintenance Repair Parts
and Special Tools List
Organizational Maintenance Manual
Organizational Maintenance Repair Parts and
Special Tools List
Electric Motor and Generator Repair
Preservation of USAMEC Mechanical Equipment
for Shipment and Storage
Administrative Storage of Equipment
Destruction of Materiel to Prevent Enemy Use
A-1
INDEX
A
Paragraph
Page
Alternator ..................................................3-2
3-1
B
Brake pedal.............................................5-16
5-21
O
Paragraph
Page
Oil pan ....................................................3-12
Oil pressure relief valve ..........................3-14
Oil pump .................................................3-13
3-15
3-19
3-16
P
C
Camshaft, bearings and
valve lifters ........................................3-24
Carburetor.................................................3-8
Carriage and backrest ..............................4-7
Column .....................................................5-4
Crankshaft, main bearings,
gears and pulley................................3-21
Cylinder head, block,
and sleeves .......................................3-20
D
Description..............................1-4.3-5,5-1
Drive axle assembly......................... 2-9,5-18
Drive axle housing and
differential ........................................5-20
E
Engine removal and
disassembly .....................................3-19
3-50
3-8
4-10
5-5
3-42
3-36
1-1,3-7,5-1
2-6,5-22
3-36
3-53
1-1
3-14
5-5
G
Governor ..................................................3-9
3-12
H
Handbrake assembly ..............................5-12
Horn button and steering
wheel...................................................5-3
Hydraulic control valve..............................4-3
Hydraulic control valve
and levers .........................................2-13
Hydraulic lift assembly ............................2-11
Hydraulic lift cylinder .................................4-6
Hydraulic lilt mast......................................4-7
Hydraulic pump assembly.......................2-10
Hydraulic reservoir ....................................4-4
5-5
4-3
2-12
2-10
4-8
4-10
2-9
4-6
3-34
M
Maintenance repair parts ..........................2-3
Maintenance requirements.. .....................2-7
Master cylinder .......................................5-14
2-1
2-5
5-19
R
Radiator ...................................................3-6
Reporting of errors ...................................1-3
3-7
1-1
3-43
1-1
5-8
2-1
3-5
5-12
5-12
2-13
5-13
5-1
T
5-16
I
Ignition coil ...............................................3-4
Inching pedal and
brake pedal ........................................3-1
5-23
5-21
2-1
5-10
4-1
S
Scope ......................................................1-1
Shifting mechanism ...........................5-6
Special tools and
equipment. ..........................................2-2
Starter motor ............................................3-3
Steer wheel bearings ................................5-9
Steering axle and
wheels ................................................5-8
Steering axle assembly .........................2-14
Steering axle and tie
rods ..................................................5-10
Steering gear . ..........................................5-2
5-24
F
Flywheel, ring gear and
housing .............................................3-26
Forms and records....................................1-2
Fuel tank ................................................3-10
Steering unit..............................................5-5
Pistons and connecting
rods...................................................3-22
Planetary gears, axle
shaft, wheel hubs ..............................5-19
Power booster ........................................5-17
Power plant...............................................2-3
Power steering cylinder ............................5-7
Pump assembly . ................................4-2
Tilt cylinder ........................................2-124-5
Timing gears and
cover .................................................3-25
Tools and equipment ................................2-1
Torque converter and
pump.................................................3-15
2-12,4-6
Transmission assembly ..........................3-16
Troubleshooting .......................................2-5
3-24
2-1
U
Universal joint .........................................5-21
526
V
Valves and rocker
arm assembly ..................................3-23
3-46
W
Wheel brake assembly. ..........................5-13
Wheel cylinder . ......................................5-15
5-17
5-21
3-52
2-1
3-20
3-7
I-1
By Order of the Secretary of the Army:
Official:
W. C. WESTMORELAND
General United States Army.
Chief of Staff
VERNE L. BOWERS.
Major General, United States Army.
The Adjutant General.
Distribution:
To be distributed in accordance with DA Form 12-25, Sec. 1 (qty rqr Block #195), Direct/General Support
requirements for Truck Fork Lift: Gasoline.
U.S. GOVERNMENT PRINTING OFFICE : 1994 0 - 160-873
PIN: 028303-000
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Why do I do it? I am tired of sleazy CD-ROM sellers, who take publicly
available information, slap “watermarks” and other junk on it, and sell it.
Those masters of search engine manipulation make sure that their sites that
sell free information, come up first in search engines. They did not create it...
They did not even scan it... Why should they get your money? Why are not
letting you give those free manuals to your friends?
I am setting this document FREE. This document was made by the US
Government and is NOT protected by Copyright. Feel free to share,
republish, sell and so on.
I am not asking you for donations, fees or handouts. If you can, please
provide a link to liberatedmanuals.com, so that free manuals come up first in
search engines:
<A HREF=http://www.liberatedmanuals.com/>Free Military and Government Manuals</A>
– Sincerely
Igor Chudov
http://igor.chudov.com/
– Chicago Machinery Movers

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