service repair manual

1. SERVICE REPAIR
H3.50XL H4.00XL-5 H4.00XL-6 H4.50XL H5.00XL [F005]

2. 1
INTRODUCTION
GENERAL
This section has the description and the repair proce-
dures for the speed reducer and differential.
DESCRIPTION (See FIGURE 1.)
The speed reducer and differential are installed in a
common housing as an assembly. The speed reducer is a
single stage reducer with a small drive gear and a large
driven gear. The speed reducer transfers power between
the powershift transmission and the ring and pinion
gears. It decreases the revolutions per minute between
the engine and the drive axle.
The ring and pinion set of gears is also a single stage
speed reducer. The ring and pinion gears transfer the
power to the drive axles and drive wheels.
The differential assembly is fastened to the ring gear.
The ends of the axle shafts have splines that fit into the
differential side gears.
REPAIRS
REMOVAL
The speed reducer and differential are in the same hous-
ing. The normal procedure is to remove the complete
drive axle and speed reducer as an assembly from the lift
truck.
1. Remove the carriage and mast assembly as described
in the section THE MAST, 4000 SRM 340.
2. Disconnect the brake lines at the wheel cylinders.
3. Remove the parking brake lever from the cowl. Re-
move the clamps for the parking brake cables at the
frame.
4. Put blocks on both sides (front and back) of the steer-
ing tires so that the lift truck can not move. Connect a
lifting device to the front of the frame. Put a floor jack
under the speed reducer to hold the drive axle assembly
in position. Remove the four large capscrews that hold
the drive axle assembly to the frame. These capscrews
are tightened to 1000 N.m (740 lbf ft). See FIGURE 2.
5. Raise the lift truck frame. Make sure the parking
brake cables that are still attached to the drive axle as-
sembly move freely. Make sure the output yoke for the
drive shaft slides out of the transmission. Remove the
drive axle assembly from under the lift truck.
DISASSEMBLY (See FIGURE 1.)
1. Drain the oil from the drive axle assembly.
WARNING
Completely remove the air pressure from the tire
before it is removed from the drive axle. Air pressure
in the tires can cause the tire and wheel parts to
explode, causing serious injury or death. Tires and
wheels must be changed by trained service
personnel.
2. Put the drive axle assembly on blocks. Remove the
axle shafts. See the section for THE DRIVE AXLE,
1400 SRM 361.
3. Remove the drive shaft from the drive gear of the
speed reducer. Remove the cover from the speed
reducer. Connect a lifting device to the speed reducer
housing. Remove the capscrews that hold speed reducer
housing to the drive axle housing. Separate the speed
reducer housing from the drive axle housing. DO NOT
damage the surfaces where the housings join. Lift the
speed reducer and differential assembly away from the
drive axle housing.
4. If the same parts for the differential (bearings and
gears)aregoingtobeinstalledagain,checktheringgear
and pinion clearance. Use the procedures described in
ASSEMBLY, Differential, in this section. Also, when
removing the adjustment rings, count the number of
turns it takes to remove each adjustment

3. 2
FIGURE 1. SPEED REDUCER AND
DIFFERENTIAL
11. THRUST WASHER
12. SIDE GEAR
13. SPIDER GEAR
14. SNAP RING
15. PILOT BEARING
16. PINION
17. BEARING
18. SHIM
19. BEARING CARRIER
20. SPACER
1. HOUSING
2. THRUST SCREW
3. BEARING CAP
4. BEARING CONE
5. BEARING CUP
6. ADJUSTMENT RING
7. AXLE SHAFT
8. DIFFERENTIAL CASE
9. RING GEAR
10. SPIDER
21. DRIVE GEAR
22. DRIVEN GEAR
23. COVER
24. SEAL

4. 3
FIGURE 2. DRIVE AXLE
11757
1. BRAKE LINE
2. CAPSCREW FOR MOUNT
1
2
FIGURE 3. REMOVE THE SPEED REDUCER
11757
ring. Use the number of turns during the assembly pro-
cedures to put the adjustment rings in the same position.
FIGURE 4. MAKE IDENTIFICATION MARKS
BEFORE DISASSEMBLY
E026
1. IDENTIFICATION MARKS
1
5. Make identification marks with a punch on the bear-
ing caps, adjustment rings and the housing. The bearing
caps and adjustments must be assembled in the same
position in the housing. See FIGURE 4.
6. Remove the two special cotter pins that lock the ad-
justment rings in position.
7. Loosen the four capscrews for the bearing caps. If
necessary, remove the adjustment rings as described in
step 4, above. Remove the bearing caps, adjustment
rings and bearing cups.
8. Remove the ring gear and differential assembly from
the housing.
9. Disassemble the ring gear and the differential assem-
bly as needed for repairs. Use a punch to mark the differ-
ential cases so that they will be assembled in the same
position. If necessary, remove the bearings from the dif-
ferential case with a puller or a press.
10. Remove the capscrews that hold the bearing for the
drive gear in the housing. Remove the eight capscrews
for the bearing carrier. Remove the drive gear assembly,
pinion, bearing carrier and bearings.
11. Put the driven gear in a vise with soft jaws. Remove
the nut and the driven gear from the pinion shaft. The
pinion nut is tightened to 1100 N.m (810 lbf ft).

5. 4
CLEANING
WARNING
Cleaning solvents can be flammable and toxic, and
can cause skin irritation. When using cleaning sol-
vents, always follow the safety instructions of the sol-
vent manufacturer.
Cleanthepartsinasolvent.Donotusesteamorgasoline
to clean the parts.
INSPECTION
1. Careful inspection of the parts before assembly is
very important. Inspect all bearing surfaces. Replace all
bearings that are worn or damaged. Remove all bearings
needing replacement with a correct puller or press. The
parts will become damaged if a drift and hammer is
used.
2. Inspect the ring gear and pinion for wear and damage.
When necessary to replace either the pinion or ring gear,
thegearsmustbereplacedasaset.Inspectthefaceofthe
thrust screw for the ring gear for wear or damage.
3. Inspect the differential assembly for wear and dam-
age. The thrust washers must be replaced in sets. Differ-
ential gears and side gears must be replaced in complete
sets. Check the holes in each differential half where the
spider assembly is connected. Check that the spider and
the holes for the spider in the differential case are round.
4. Inspect the axle shafts for cracks, damage or wear.
Axle shafts must be straight.
5. Inspect the housing for cracks and damaged surfaces.
Make necessary repairs before assembly. The threads
must be clean to make correct adjustments.
ASSEMBLY
Pinion Assembly (See FIGURE 5.)
1. Assemble the pinion assembly. Install the pilot bear-
ing and one of the bearing cones on the pinion. Always
push on the inner race when installing the bearings. The
bearings must be against the shoulders of the pinion. In-
stall the snap ring to hold the pilot bearing on the pinion.
2. Install the bearing cups in the bearing carrier. Install
the bearing carrier on the pinion. Install the two spacers
removed during disassembly. The spacers are available
in the following widths:
in mm in mm
0.238 (6.05) 0.267 (6.78)
0.239 (6.07) 0.273 (6.93)
0.240 (6.10) 0.279 (7.09)
0.24l (6.12) 0.285 (7.23)
0.242 (6.15) 0.291 (7.39)
0.243 (6.17) 0.297 (7.54)
0.255 (6.48) 0.303 (7.70)
0.26l (6.63)
Use two spacers in any sequence to give the correct
preload on the pinion bearings. Install the second bear-
ing cone on the pinion.
FIGURE 5. THE PINION ASSEMBLY
9106
1. SNAP RING
2. PILOT BEARING
3. PINION
4. BEARING CONE
5. BEARING CUP
6. SPACER
7. SHIM
8. BEARING CARRIER
9. DRIVEN GEAR
10. NUT

6. 5
NOTE: The special nut for the pinion can be installed
only once. When making adjustments, use a nut with the
tapered end removed. When the adjustment is correct,
install a new nut.
3. Install the driven gear and nut on the pinion. Put the
driven gear in a vise with soft jaws. Make sure you do
not damage the gear. Tighten the nut to 1100 N.m (812
lbf ft). Check the rotating torque of the pinion caused by
the pre–load on the bearings. The limits are 1.2 to 4.0
N.m (10 to 35 lbf in). See FIGURE 6.
FIGURE 6. CHECK THE PINION BEARING
ADJUSTMENT
9147
4. Install the shims between the bearing carrier and the
housing. See FIGURE 12. Install the pinion assembly in
the speed reducer housing. If the pinion and ring gear
were not replaced, use the shims that were removed.
Tighten the eight capscrews to 90 N.m (66 lbf ft). If the
pinion and ring gear were replaced, see TABLE 1. for
finding the correct shim measurements.
NOTE: The pinion and ring gear are made in sets. Both
the ring gear and pinion have marks with the same num-
ber. If the original pinion is not available and the + or –
dimension is not known, adjust the pinion to the test di-
mension shown in FIGURE 12. The test dimension is
190.5 mm (7.500 in). Use shims between the bearing
carrier and the speed reducer housing to obtain the test
dimension + or – 0.025 mm (0.001 in).
Differential
NOTE: When installing the capscrews for the differen-
tial assembly, put a small amount of oil on the threads.
1. If the differential bearings must be replaced, press
new bearings on each differential half. Assemble the
differential and ring gear.
CAUTION
The ring gear must be heated before it is assembled
on the differential half. Heat the ring gear in water to
82°C (180°F) for approximately 10 minutes. This
heatwillpermiteasierinstallation.Donotuseapress
to install the ring gear. A press will damage the
surfaces and cause the ring gear to align incorrectly.
TABLE 1. ADJUSTMENT OF SHIMS FOR THE PINION ASSEMBLY
EXAMPLES 1 2 3 4
If the numbers are given in inches:
Number on OLD GEAR + 0.012 + 0.012 + 0.010 – 0.010
Number on NEW GEAR – (+ 0.010) – (– 0.010) – (+ 0.012) – ( – 0.012)
SHIMS TO BE REMOVED FROM OLD SET + 0.002 in + 0.022 in – 0.002 in + 0.002 in
(ADD SHIMS)
If the numbers are given in millimeters:
Number on OLD GEAR + 0.31 + 0.31 + 0.26 – 0.26
Number on NEW GEAR – (+ 0.26) – (– 0.26) – (+ 0.31) – (– 0.31)
SHIMS TO BE REMOVED FROM OLD SET + 0.005 mm + 0.57 mm – 0.005 mm + 0.05 mm
(ADD SHIMS)

7. 6
FIGURE 7. THE DIFFERENTIAL ASSEMBLY
9107
1. ADJUSTMENT RING
2. BEARING CUP
3. BEARING CONE
4. DIFFERENTIAL CASE
5. RING GEAR
6. THRUST WASHER
7. AXLE GEAR
8. SPIDER
9. SPIDER GEAR (4)
10. THRUST WASHER (4)
TIGHTENING SEQUENCE
Tighten the ring gear bolts to 70 N.m (50 lbf ft) accord-
ing to the pattern in FIGURE 7. Then tighten the
capscrews to 140 N.m (105 lbf ft).
2. Assemble the differential gear assembly if it was dis-
assembled. (See FIGURE 8.) Align the punch marks
and fasten the differential halves together. Use a thread
locking compound (Hyster Part No. 257291) on the
capscrews. Use four capscrews at equal spaces. Check
that the differential gears rotate correctly. Install the
other capscrews and tighten all capscrews to 140 N.m
(105 lbf ft). Check that the differential gears rotate cor-
rectly.
3. Put the bearing cups over the bearing cones and install
the differential assembly in the housing. Each bearing
must be assembled in the same position from which it
was removed. Tighten each adjustment ring against the
bearing by hand. Make sure that each adjustment ring is
installed in the same position from which it was re-
moved.
FIGURE 8. INSTALL THE DIFFERENTIAL
ASSEMBLY
1. IDENTIFICATION MARKS
8646
1

8. 7
1. ADJUSTMENT RING
2. IDENTIFICATION MARKS
8646
FIGURE 9. INSTALL THE BEARING CAPS
1
4.Installthebearingcaps.Makesureeachbearingcapis
installed in the same position from which it was re-
moved.
CAUTION
If the bearing caps do not fit correctly, check that the
threads of the adjustment ring are aligned. If force is
applied to the threads when not aligned, the
adjustment rings or the bearing caps can be
damaged.
Tighten the capscrews holding the bearing caps only so
that the adjustment rings can be turned with a tool. Ad-
just the ring gear and pinion as shown in FIGURE 10.
and FIGURE 11.
5.Tightenthecapscrewsholdingthebearingcapsto225
N.m (165 lbf ft). Install the two special cotter pins that
lock the adjustment rings in position.

9. 8
FIGURE 10. ADJUST THE GEAR CLEARANCE
STEP 1. Fasten a dial indicator to the housing so that the movement of the ring gear can be measured.
Loosen the adjustment ring opposite the dial indicator until the dial indicator just indicates movement.
Tighten the same adjustment ring to get zero clearance.
STEP 2. Rotate the ring gear 360 degrees while checking with the dial indicator. Check that the surface
of the ring gear opposite the teeth does not indicate a variation of more than 0.08 mm (0.003 in). If the vari-
ation is more than 0.08 mm (0.003 in) remove the differential assembly and check the ring gear mount sur-
face.
STEP 3. Tighten each adjustment ring one notch from zero clearance so that the differential bearings have
a pre–load.
NOTE: Do not permit the ring gear to touch the pinion during these adjustments. The gears can be dam-
aged and the dial indicator will give a bad reading. The ring gear can be moved away from the pinion with
the adjustment ring.
STEP 4. Adjust gear clearance. This gear clearance is the distance between the teeth of the ring gear and
pinion. Adjust the clearance to 0.15 to 0.25 mm (0.006 to 0.010 in). Adjust the clearance by moving the ring
gear only. Adjust the ring gear by loosening one adjustment ring and tightening the other adjustment ring
the same amount. Check the contact pattern of the gear teeth as shown in FIGURE 11.
8648

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11. 9
WRONG TOOTH CONTACT
CORRECT TOOTH CONTACT
5840
FIGURE 11. ADJUST THE RING GEAR AND PINION TOOTH CONTACT
STEP 1. Apply a colored dye or grease to approx-
imately 12 of the ring gear teeth.
STEP 2. Apply a small friction load to the edge of
the ring gear so that the ring gear does not turn
easily. Rotate the ring gear one revolution by turn-
ing the pinion.
STEP 3. Check the tooth contact pattern on the
ring gear. Make sure that the pattern is checked
on the side of the tooth where the pinion applies
the force.
The contact area is the center between the top and
the bottom of the tooth. The contact area will be
almost the full length of the tooth.
The contact area is the center between the top and
the bottom of the tooth. The contact area is toward
the inner circumference of the ring gear.
NORMAL
PATTERN
DURING
ADJUSTMENT
WEAR
PATTERN
WHEN IN
LIFT TRUCK
The pinion is too close to the center
of the ring gear.
Remove shims to move pinion away from
the ring gear. Check that the clearance is
correct. Some movement of the ring gear
toward the pinion can be necessary.
The pinion is too far away from the
center of the ring gear.
Add shims to move pinion toward ring
gear. Check that the clearance is
correct. Some movement of ring gear
away from the pinion can be necessary.

12. 10
6. Install the bearings and snap rings on the drive gear.
Install the drive gear in the housing. Install the
capscrews and washers to hold the bearing in the hous-
ing. Tighten the capscrews to 20 N.m (15 lbf ft). See
FIGURE 12.
7. Use a sealant (Hyster Part No. 280472) on the flange
of the cover and install the cover for the speed reducer
on the housing. Tighten the capscrews to 20 N.m (15 lbf
ft). Install the seal for the drive gear in the cover. Make
sure the seal is even with the surface of the cover.
8.Installthethrustscrewandlocknut.Tightenthethrust
screw until it contacts the ring gear. Loosen the thrust
screw approximately 55° to 80°. The correct clearance
is 0.38 to 0.50 mm (0.015 to 0.020 in). When the adjust-
ment is correct, tighten the lock nut.
FIGURE 12. SPEED REDUCER AND DIFFERENTIAL
11756
1. COVER
2. DRIVE GEAR
3. DRIVEN GEAR
4. PINION
5. RING GEAR
6. DIFFERENTIAL CASE
7. BEARING CARRIER
8. HOUSING
9. SPACERS
10. SHIMS
11. SEAL
12. TEST DIMENSION
190.5 mm
(7.500 in)
12
3
4
5
6
7
8
9
10
11
12

13. 11
9. Connect a lifting device to the speed reducer. Use a
sealant (Hyster Part No. 264159) on the flange of the
speed reducer. Install the speed reducer on the drive axle
housing. Tighten the capscrews to 90 N.m (65 lbf ft).
10. Install the axles shafts, wheels and tires. See the sec-
tion for THE DRIVE AXLE, 1400 SRM 361.
11. Install the universal joints and drive shaft on the
drive gear. Use a thread locking compound (Hyster Part
No. 264134) on the threads of the capscrews. Tighten
the capscrews in a cross pattern to 50 N.m (35 lbf ft). In-
stall the output flange for the transmission to the univer-
sal joint. Use a thread locking compound (Hyster Part
No. 264134) on the threads of the capscrews. Tighten
the capscrews in a cross pattern to 50 N.m (35 lbf ft).
INSTALLATION (See FIGURE 13.)
1.Putthedriveaxleassemblyunderthelifttruck.Lower
the lift truck frame so that the drive axle assembly can be
connected. Install the output yoke for the transmission
as the drive axle is installed. Be careful not to damage
the oil seal in the transmission housing.
2. Install the four large capscrews that hold the drive
axle assembly to the frame. Tighten the capscrews to
1000 N.m (740 lbf ft). (See FIGURE 2.)
3. Connect the brake lines to the wheel cylinders.
4. Connect the parking brake mechanism to the frame.
Install the parking brake lever on the cowl.
5. Fill the speed reducer and axle assembly with
85W–140 gear oil.
6. Remove the air from the brake system. Check that the
service brakes and the parking brake operate correctly.
7. Install the mast and carriage as described in the sec-
tion for the THE MAST, 4000 SRM 340.
FIGURE 13. TRANSMISSION AND SPEED REDUCER
11784
1. POWERSHIFT
TRANSMISSION
2. OUTPUT YOKE
3. UNIVERSAL JOINT
4. DRIVE SHAFT
5. SPEED REDUCER AND
DIFFERENTIAL
1
2
3
4 5
3