1

PLANETARY DRIVE AXLE

GENERAL

This section has a description, repair procedures, and
troubleshooting guide for the planetary drive axle. The
service brakes are part of the components in the plane-
tary hubs and are included in the procedures for disas-
sembly and assembly of the drive axle. The disc parking
brake is fastened to the differential.

DESCRIPTION, PLANETARY DRIVE AXLE

The drive shaft from the transmission is connected to the
differential in the drive axle housing. The axle shafts

transfer the torque from the differential to the planetary
gears.

The ends of the outer axle shafts have splines that en-
gage the planetary sun gears. See FIGURE 2. A sun gear
turns when the axle shaft turns. The planetary ring gear
is engaged with the splines on the spindle and does not
turn. The planet carrier (planetary drive flange) has
three pinion gears that engage the sun gear and the inter-
nal ring gear. The planet carrier is installed on the hub
with capscrews. When the sun gear rotates, the pinion
gears move around the ring gear, and turn the planet car-
rier, hub, and when as they move.

FIGURE 1. PLANETARY DRIVE AXLE

1

4

3

2

1. HOUSING, DRIVE AXLE
2. DIFFERENTIAL
3. HOUSING, SERVICE BRAKES
4. HUB, PLANETARY GEAR
5. PARKING BRAKE

5

4

3

6

6

7

7

8

8

6. INLET PORT, SERVICE BRAKE ACTUATION
7. INLET PORT, BRAKE COOLING CIRCUIT
8. OUTLET PORT, BRAKE COOLING CIRCUIT

2

FIGURE 2. PLANETARY GEAR OPERATION

12222

1. STATIONARY RING GEAR (ON SPLINES OF SPINDLE)
2. PLANETARY GEAR (ROTATES ON SHAFT IN DRIVE

FLANGE

3. PLANET CARRIER (PART OF DRIVE FLANGE AND

FASTENED TO THE HUB)

4. SUN GEAR (ENGAGED WITH THE SPLINES ON THE

OUTER AXLE SHAFT)

1

4

3

2

TABLE 1.

APPROXIMATE WEIGHTS OF AXLE

PARTS

COMPONENT

WEIGHT

COMPONENT

kg

lb

WIDE AXLE ASSEMBLY

1385

3050

STANDARD AXLE

ASSEMBLY

1135

2500

14.00 x 24 SOLID RUBBER

TIRE AND WHEEL

ASSEMBLY

545

1200

12.00 x 24 SOLID RUBBER

TIRE AND WHEEL

ASSEMBLY

405

890

14.00 x 24 PNEUMATIC

TIRE AND WHEEL

ASSEMBLY

315

695

12.00 x 24 PNEUMATIC

TIRE AND WHEEL

ASSEMBLY

200

440

DRIVE AXLE, REMOVAL

NOTE: The planetary assemblies and the service brake
assemblies can be disassembled with the drive axle in-
stalled in the lift truck. The following procedure is for
removal of the complete drive axle. See PLANETARY
GEAR in this section for disassembly and assembly pro-
cedures for the planetary gear assembly and the service
brakes.

NOTE: If a 10–ton capacity crane is available, the drive
axle can be removed without removing the mast. Re-
move the forks and carriage or the container handler. Do

the following steps without removing the mast. Then
use the crane to raise the lift truck so that there is clear-
ance to remove the drive axle.

WARNING

Make sure that the lifting device has the capacity to
lift the axle assembly and components. See
TABLE 1. for the approximate weights of axle com-
ponents.

1. Put blocks under the lift truck frame to raise the drive
wheels from the ground. See “How To Put The Lift
Truck on Blocks” in the OPERATING MANUAL or
the PERIODIC MAINTENANCE, 8000 SRM 662.

2. Remove the mast assembly from the lift truck as de-
scribed in the section THE MAST, 4000 SRM 660 or
THE MAST (WITH CONTAINER ATTACH-
MENT, 4000 SRM 661).

3. Put a drain pan under the differential housing and
drain the oil.

WARNING

Before disconnecting any hydraulic lines, release
pressure from the hydraulic circuit as follows:

a. Shut–off the engine and completely lower the

carriage.

b. Operate the lift/lower lever and the brake ped-

als until the hydraulic pressure is released.

4. The service brakes use hydraulic oil from the hydrau-
lic system for actuation and cooling. Drain the hydraulic

3

oil from each brake housing. Disconnect the oil coolant
lines. Disconnect the oil lines that actuate the brakes.
See FIGURE 1. Put caps on the open hydraulic lines.

5. Disconnect the universal joint from the yoke at the
differential. Disconnect hydraulic line to the parking
brake.

6. If the axle must be disassembled for repairs, rotate the
planetary gear so that the drain and fill port is at the low-
est point. See FIGURE 3. Drain the lubricant from each
planetary gear assembly.

FIGURE 3. PLANETARY GEAR, DRAIN AND

FILL

1. DRAIN AND

FILL PORT

1

WARNING

Completely remove the air pressure from the tires
before removing the wheels from the lift truck. Air
pressure in the tires can cause the tire and rim parts
to explode causing serious injury or death.

Always wear safety glasses.

7. Remove the drive wheels from the axle:

a. Raise the drive wheels to remove the weight from

the tires, but so the tires are still touching the
floor. Loosen the wheel nuts just enough so they
can be easily removed. Remove the air from the
tires. Remove the valve core to make sure all of
the air is out of the inner tube. Push a wire
through the valve stem to make sure that the valve
stem does not have a restriction.

b. Raise the axle so the tires and wheels can be re-

moved. Remove the wheel nuts. Use a tire jack to
remove the tires and wheels.

c. If a tire jack is not available, raise the axle only

enough so the tires are just touching the floor.
Slide the tires from the axle while they are still on
the floor. It is helpful to put a lubricant on the
floor (oil, grease, liquid soap, etc.).

WARNING

Make sure to clean the floor thoroughly if oil, grease,
liquid soap, etc. was used as a lubricant to help re-
move the wheel and tires.

8. Use a lifting device (floor jack or the forks of a lift
truck) to remove the drive axle. Put the lifting device un-
der the axle to give it support. Remove the eight bolts
and nuts that hold the axle to the frame. Remove the
drive axle from the lift truck frame.

DRIVE AXLE, INSTALLATION

1. Use a lifting device (floor jack or the forks of a lift
truck) to install the drive axle under the lift truck. Install
the eight bolts and nuts that hold the axle to the frame.

2. Add air to the tires in a safety cage. Install the tires on
the drive axle. Also see PERIODIC MAINTE-
NANCE, 8000 SRM 662 for additional information for
tire installation. Tighten the wheel nuts to the correct
torque.

3. Connect the oil lines and the oil coolant lines to the
brake housings.

4. Connect the universal joint to the yoke at the differen-
tial. Connect the oil line to the parking brake.

5. Install the correct lubricant in the differential. See
PERIODIC MAINTENANCE, 8000 SRM 662

6. If the mast was removed, install the mast. See the sec-
tion THE MAST, 4000 SRM 660 or THE MAST
(WITH CONTAINER ATTACHMENT), 4000 SRM
661.

7. Install the carriage and forks or the container handler.

8. When the hydraulic system can be operated, remove
the air from the parking brake. Use the special fitting on
the parking brake caliper to remove the air.

WARNING

Check all wheel nuts after 2 to 5 hours of operation
when new trucks are put into operation or when
wheels have been removed and installed. Tighten the

4

nuts in a cross pattern to the correct torque value
shown in the MAINTENANCE SCHEDULE table.
When the nuts stay tight for eight hours, the interval

for checking the torque can be extended to 150
hours.

FIGURE 4. PLANETARY DRIVE AND BRAKE ASSEMBLY

2

1. WHEEL RIM (REFERENCE)
2. HOUSING, DRIVE AXLE
3. HOUSING, SERVICE BRAKE
4. SPINDLE
5. OIL SEAL
6. WHEEL BEARING (2)
7. LOCK PLATE
8. WHEEL HUB
9. SUN GEAR

10. PLANETARY GEAR AND SPIDER ASSEMBLY

11. THRUST BUTTON, SUN GEAR

5

4

3

6

1

7

1

6

8

9

10

12

13

14

15

16

17

18

19

12. ADJUSTMENT NUT
13. RING GEAR
14. RING GEAR HUB
15. DUAL OIL SEAL
16. BRAKE DISCS
17. INLET, COOLING OIL
18. BRAKE PISTON
19. DUAL OIL SEAL
20. OUTLET, COOLING OIL
21. AXLE

20

21

11

12963

5

PLANETARY GEAR AND SERVICE
BRAKE

Disassembly (See FIGURE 5.)

FIGURE 5. DISASSEMBLY OF THE PLANETARY AXLE (1 of 3)

CAUTION

Do not damage the seal surfaces between the

planetary spider and the wheel hub.

The planetary spider assembly is heavy. Use a

sling and lifting device to move the planetary

spider assembly from the wheel hub.

STEP 2. Pull the ring gear from the wheel hub.

NOTE: The sun gear is held to the axle shaft with a
snap ring. Disassemble the axle assembly only if re-
pairs are necessary.

STEP 3. Remove snap ring and remove the sun

gear from the axle. Remove the thrust
washer for the sun gear from the axle.

Do not remove the adjustment nut from the

spindle until the wheel hub has a support. The

wheel hub and planetary gear components are

heavy and can cause injury and damage if they

fall.

STEP 4. Remove the two screws that fasten the

lock plate to the ring gear hub. Remove
the lock plate and the adjustment nut
from the spindle.

WARNING

STEP 1. Drain the oil from the planetary gear

housing. remove the 30 capscrews and
remove the planetary spider assembly.
Disassemble the planetary gear and
spider assembly only if repairs are
necessary.

1

2

3

1. SNAP RING
2. SUN GEAR
3. THRUST WASHER

1

2

1. LOCK PLATE
2. ADJUSTMENT NUT

12964

6

FIGURE 5. DISASSEMBLY OF THE PLANETARY AXLE (2 of 3)

STEP 5. Remove the ring gear hub. Pull it

straight from the wheel hub and from the
spindle. Use a puller as necessary to
separate the ring gear hub from the ring
gear.

The wheel hub is heavy. Use a sling or other sup-
port to hold the wheel hub when it is removed.

STEP 6. Remove the wheel hub. Pull the wheel

hub from the brake housing and from the
spindle. Use care to not damage the oil
seal where the wheel hub joins the brake
housing.

STEP 7. If the axle must be removed or the brake

must be repaired, remove the spindle.
Remove the 16 capscrews that hold the
spindle to the brake housing. Carefully
pull the spindle from the axle so that the
oil seals are not damaged.

STEP 8. Remove the 11 stationary discs and 10 brake discs

of the brake assembly. If the axle must be removed,
pull the axle straight from the axle housing.

NOTE: All discs are not shown.

WARNING

1

1. CONE, WHEEL BEARING
2. CUP. WHEEL BEARING
3. OIL SEAL

1

2

3

12964

12964

12964

12964

7

FIGURE 5. DISASSEMBLY OF THE PLANETARY AXLE (3 of 3)

STEP 9. Remove the four capscrews and piston

return springs. Remove the brake piston
assembly from the brake housing.
Remove the seals and back–up rings
from the brake piston.

STEP 10.Remove four capscrews that hold the

brake housing to the axle housing and
remove the brake housing.

12964

12964

Assembly (See FIGURE 6.)

NOTE: Lubricate all of the parts with clean axle lubri-
cant during assembly.

8

FIGURE 6. ASSEMBLY OF THE PLANETARY AXLE (1 of 3)

STEP 1. Install a new oil seals in the end of the axle

housing.

STEP 3. Align the brake housing correctly with holes

in the axle housing. Install the four
capscrews that hold it in position. Align the
holes of the brake piston with the axle
housing and install the four capscrews and
piston return springs.

STEP 4. Carefully install the axle shaft. Make

sure the oil seal for the axle shaft is
not damaged during installation.

STEP 2. Carefully install new back–up rings and

seals on the brake piston. Each back–up
ring is toward the outside edge of the
piston. Install the brake piston in the brake
housing.

2

1

1

2

3

4

5

1. SPACER
2. OIL SEAL

1. BACK–UP RING
2. QUAD RING SEAL
3. PISTON
4. QUAD RING SEAL
5. BACK–UP RING

STEP 5. Install the 11 stationary discs and 10

brake discs of the brake assembly.
Align the teeth of the brake discs so
that the axle can be installed.

STEP 6. Install new dual oil seals for the axle in

the spindle.

1. SPACER
2. OIL SEAL

1

2

9

FIGURE 6. ASSEMBLY OF THE PLANETARY AXLE (2 of 3)

STEP 7. Install the spindle and align the holes.

Install the 16 capscrews and washers
and tighten them in a cross pattern to 680
to 880 Nm (500 to 650 lbf ft). Use only
Grade 8 capscrews (7/8–9 x 8.5 inch).

STEP 8. If the wheel bearing was removed from

the wheel hub, install it. Install a new oil
seal.

1. CONE, WHEEL BEARING
2. CUP. WHEEL BEARING
3. OIL SEAL

1

2

3

STEP 9. Carefully install the wheel hub on

spindle and use a support so that the
parts are not damaged. Install the outer
wheel bearing cup.

1

1. CUP, WHEEL BEARING
2. WHEEL HUB

2

STEP 10.Install the outer wheel bearing cone on the

ring gear hub. Install the ring gear hub into
the wheel hub. Install the adjustment nut.

STEP 11. Wheel Bearing Adjustment:

Tighten the adjustment nut to 545 Nm (400 lbf ft)
while the wheel hub is rotated a minimum 1/2
rotation in each direction.

Hit the wheel hub with a mallet twice to make
sure the bearings and seals are in their posi-
tions.

Tighten the adjustment nut again to 545 Nm (400
lbf ft) while the wheel hub is rotated a minimum
1/2 rotation in each direction.

Hit the wheel hub with a mallet twice.

Loosen the adjustment nut 1/8 to 1/4 rotation.

Tighten the adjustment nut to 475 Nm (350 lbf ft)

Check that the rolling torque of the wheel hub is 8
to 14 Nm (6 to 10 lbf ft) in each direction.
See illustration.

Hit the wheel hub with a mallet twice.

Tighten the adjustment nut so that the rolling
torque of the wheel hub is 8 to 14 Nm (6 to 10 lbf
ft) in each direction.

Install the lock plate and the two screws that fas-
ten the lock plate to the ring gear hub.

10

FIGURE 6. ASSEMBLY OF THE PLANETARY AXLE (3 of 3)

STEP 12.Install the thrust washer for the sun

gear. Install the sun gear and snap ring.

1

2

3

1. SNAP RING
2. SUN GEAR
3. THRUST

WASHER

STEP 13.Install the ring gear.

STEP 14.If the planetary gear and spider was

disassembled, assemble it. Use new
O–rings on the shafts for the planetary
gears. Make sure the three thrust buttons
for the ring gear and the thrust button for
the sun gear are installed in the spider.

STEP 15.Put a bead of liquid sealant on the flange

of the spider assembly where it fastens to
the wheel hub. Install the planetary gear
and spider assembly on the wheel hub.
Install the 30 washer and capscrews.
Tighten the capscrews to 115 to 155 Nm
(85 to 115 lbf ft) in a cross pattern. Use
only Grade 8 capscrews (1/2–13 inch).

STEP 16.If the axle is installed in the lift truck,

rotate the planetary gear hub so that
the the flil line is horizontal. Fill the
planetary gear assembly with the correct
oil. See PERIODIC MAINTENANCE,
8000 SRM 662 for oil and the
installation of the tires. See DRIVE
AXLE, INSTALLATION for installation of
the drive axle under the lift truck.

11

TROUBLESHOOTING

PROBLEM

POSSIBLE CAUSE

PROCEDURE OR ACTION

An axle shaft is broken.

Install new axle shaft.

The lift truck will not move.

The drive shaft or transmission is
damaged.

Repair or replace the drive shaft or
the transmission.

The gears in the planetary drive are
damaged.

Repair the planetary drive.

There is no sealant between the
joints of the planetary assembly.

Install sealant between joints of
planetary assembly.

The final drive has leaks

There are capscrews missing from
the cover of the planetary assembly.

Replace the missing capscrews.

The final drive has leaks

There are plugs missing from the
cover or housing of the planetary
axle.

Install the missing plugs.

The spindle oil seal is damaged.

Replace the spindle oil seal.

The final drive makes noise.

The gears or shafts in the planetary
drive are damaged.

Replace or repair the planetary
drive.

The final drive makes noise.

There is no oil in the axle.

Fill the axle with the correct oil.

12

AXLE HARDWARE TORQUE*

SIZE

LOCK NUTS

CAPSCREW AND NUTS

SIZE

Nm

lb

f

ft

Nm

lb

f

ft

1/4”–20

12–15

9–11

13–18

10–13

1/4”–28

13–18

10–13

13–18

10–13

5/16”–18

24–33

18–24

27–40

20–30

5/16”–24

27–40

20–30

27–40

20–30

3/8”–16

40–54

30–40

48–68

35–50

3/8”–24

48–68

35–50

54–74

40–55

7/16”–14

68–88

50–65

81–102

60–75

7/16”–20

81–102

60–75

88–115

65–85

1/2”–13

102–135

75–100

115–155

85–115

1/2”–20

115–155

85–115

135–175

100–130

9/16”–12

150–195

110–145

175–225

135–165

9/16”–18

175–225

130–165

200–260

150–190

5/8”–11

200–260

150–190

245–310

180–230

5/8”–18

245–310

180–230

285–365

210–270

3/4”–10

265–475

270–350

420–540

310–400

3/4”–16

420–540

310–400

490–640

360–470

7/8”–9

595–785

440–580

680–860

500–650

7/8”–14

680–880

500–650

780–1015

575–750

1”–8

880–1185

650–875

1050–1355

775–1000

1”–12

985–1290

725–950

1150–1490

850–1100

1”–14

985–1290

725–950

1150–1490

850–1100

* Torque values are for parts lubricated with light weight oil

13

NOTES