
REAR AXLE AND FINAL DRIVE
1
DESCRIPTION AND OPERATION DESCRIPTION
The welded steel rear axle casing houses a separate
spiral bevel type differential unit, which is off set to the
right of the vehicle centre line. The differential unit
drives the rear wheels via the axle shafts and fully
floating hubs which are mounted on tapered roller
bearings.
Lubrication
The differential is lubricated with oil and the hub
bearings with grease.The hub bearings are fitted with inner and outer seals.
The outer seals prevent the differential oil mixing with
the hub grease and the inner seals prevent dirt
ingress into the hub.
Ventilation
Ventilation of the hub bearings is through the outer oil
seals and the differential ventilation pipe, which
terminates at a high level.
Rear axle hub - 90
1.Axle casing
2.Ventilation pipe
3.Axle shaft
4.Wheel studs and hub
5.Wheel bearing stub axle6.Wheel bearings
7.Inner hub seal
8.Outer hub/axle shaft seal
9.Hub lock plate, thrust washer and nuts
10.Brake disc

REAR AXLE AND FINAL DRIVE
1
FAULT DIAGNOSIS FAULT DIAGNOSIS
Complaint - Oil leaks
An external leak of lubrication from the hub seals can
be caused by a faulty internal seal. For example, if the
seals which separate the differential from the hubs are
faulty and the vehicle is operating or parked on an
embankment, oil from the differential may flood one
hub resulting in a lack of lubrication in the differential.
When a seal is found to be leaking check the axle
ventilation system, as a blockage can cause internal
pressure to force oil past the seals.
See 'Description and Operation' for illustrations of oil
seal locations.
When investigating hub seal leaks check the grease
for dilution with oil. Also check the differential oil level,
for signs of metal particles in the oil and the condition
of internal seals.
If the vehicle is driven in deep water with defective oil
seals, water may contaminate the lubricants and raise
the differential oil level, giving a false impression that
the housing has been overfilled.
Do not assume that a high oil level in the
differential is due to over filling or, that a low level
is because of an external leak.

REAR AXLE AND FINAL DRIVE
9
OVERHAUL Differential backlash checks
96.Pick up differential unit as left after instruction
52.
97.Fit differential unit and lever unit away from drive
pinion until opposite bearing cup is seated
against housing. Do not tilt unit.
98.Install a dial gauge on casing with its stylus
resting on back face of crown wheel. Zero the
gauge.
99.Lever differential unit to engage crown wheel
teeth in full mesh with drive pinion teeth. Do not
tilt unit.
100.Note total reading obtained on dial gauge.
101.From this figure subtract 0,25 mm to obtain
correct crown wheel backlash when fitted. The
result indicates value of shimming to be fitted
between differential case and bearing cone at
crown wheel side of differential.
102.Fit shim value determined in instruction 101,
taking shims from pack previously determined
during 'Differential bearing adjustment' checks,
instructions 57 to 62LRT-51-500details 1 and 2,
pressLRT-99-002, andLRT-51-504.
103.Fit remaining shims from instruction 101 to
opposite side of differential.LRT-51-501details
1 and 2, pressLRT-99-002, andLRT-51-504.
104.Fit differential unit with shims and bearings to
axle casing, using axle spreaderLRT-51-503
with pegs18G131F.
105.Remove axle spreader.106.Fit bearing caps in their correct position,
referring to relationship markings on caps and on
axle casing.
107.Tighten bearing caps fixings to
135 Nm (100
lbf/ft).
108.Mount a dial gauge on axle casing with stylus
resting on a crown wheel tooth.
109.Prevent drive pinion from rotating and check
crown wheel backlash which must be 0,15 to
0,27 mm. If backlash is not within specified
limits, repeat differential backlash checks,
instructions 96 to 102 looking for possible errors.
110.Fit differential cover and new gasket, coating
both sides of gasket with Hylomar PL 32M or an
equivalent non-setting sealant. Torque load for
fixings is
30 Nm (22 lbf/ft).
111.Reverse instructions 3 to 5 and coat threads of
hub driving member bolts with Loctite 'Studlock'
grade CVX and fit and tighten bolts evenly to
correct torque.
112.Fit rear axle assembly to vehicle
See Repair,
Rear axle
.
113.Replenish differential with recommended
lubricant
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
lubricants and fluids
. After initial axle run,
check oil level and replenish as necessary to
filler/level plug hole.
114.Where major running parts have been replaced
during servicing, it is a recommended practice to
allow axle assembly to 'run in' by avoiding,
where possible, heavy loads and high speeds
during initial running.

54FRONT AXLE AND FINAL DRIVE
2
DESCRIPTION AND OPERATION Lubrication
The differential, swivel pin housing and wheel hubs
are indiviudally lubricated and separated by oil seals
(7) and (8), see J6267A, to prevent oil transfer across
the axle when the vehicle is traversing steep inclines.
The wheel bearings are lubricated with grease and the
swivel housing and differential with oil. On later
vehicles, identified by having only a filler plug in the
swivel housing, grease is used to lubricate the
housing assembly,
Ventilation
Ventilation of the differential is through a plastic pipe
(2) which terminates at a high level in the vehicle axle.
The swivel housings ventilate through axle shaft oil
seals (8) into the differential and the hub bearings
vent via the oil seals into the swivel housing.

FRONT AXLE AND FINAL DRIVE
1
FAULT DIAGNOSIS FAULT DIAGNOSIS
Complaint - Oil leaks
An external leak of lubrication can be caused by a
faulty internal seal. For example, if the seals which
separate the differential from the swivel housings are
faulty and the vehicle is operating or parked on an
embankment, oil may leak across the axle leaving one
swivel with a high level and the opposite swivel and
differential lacking lubrication.
See 'Description and Operation' for illustrations of oil
seal locations.
When investigating leaks or checking oil levels, it is
essential that all the lubrication is drained from any
housing with a high level and that the other levels are
checked.
Swivel oil should be checked for signs of grease
leaking from the hub bearings and oil contamination of
the hub grease.
Check that the axle ventilation system is clear, as a
blockage can cause internal pressure to force oil past
the seals.
If the vehicle is driven in deep water with defective oil
seals, water may contaminate the lubricants and when
checked, give a false impression that the housing has
been overfilled with oil.
Do not assume that a high oil level is due to over
filling or, that a low level is because of an external
leak.

FRONT AXLE AND FINAL DRIVE
5
OVERHAUL 38.Place retaining plate, joint washer and oil seal
over axle flange ready for assembly.
39.Fit swivel bearing housing to axle flange with 7
bolts. Tighten to
73 Nm (54 lbf/ft).
40.Grease and fit upper and lower swivel pin taper
roller bearings.
41.Position swivel pin housing over swivel bearing
housing.
42.Coat joint washer both sides with sealing
compound and position on lower swivel pin.
43.Loosely fit brake shield bracket plus lower swivel
pin with lug outboard to swivel pin housing.
44.Loosely fit top swivel pin plus existing shims and
brake hose bracket to swivel pin housing.
45.Apply Loctite 270 or equivalent to lower swivel
pin bolts.
78 Nm (58 lbf/ft),bend over lock tabs.
46.Tighten top swivel pin bolts to
78 Nm (58 lbf/ft).
Check and adjust preload on bearings
NOTE: Swivel housing oil seal and axle
should not be fitted.
47.Attach a spring balance to ball joint bore and pull
balance to determine effort required to turn
swivel pin housing.
Resistance, once initial inertia has been
overcome, should be1.16 to 1.46 kg.Adjust by
removing or adding shims to top swivel pin.
48.When setting is correct remove top swivel bolts,
apply Loctite 270 or equivalent. Refit bolts and
tighten to
78 Nm (58 lbf/ft),and bend over lock
tabs.
49.Apply recommended grease between lips of
swivel oil seal.50.Fit oil seal, joint washer and retaining plate with
7 bolts and spring washers. Tighten to
11 Nm (8
lbf/ft).
51.Fit tie rod and drag link and secure with new
cotter pins. Tighten fixing to
40 Nm (30 lbf/ft).
52.Fit brake disc shield.
53.Loosely fit lock stop bolt and nut.
54.Apply a recommended grease between lips of
swivel housing oil seal.
55.Secure oil seal with retaining plate and securing
bolts. Tighten to
11 Nm (8 lbf/ft).
56.Fit track-rod and drag link and secure with new
cotter pins.
57.Loosely fit lock stop bolt for later adjustment.
58.Fit brake disc shield.
Fit driveshaft and stub axle
59.Insert axle shaft, and when differential splines
are engaged, push assembly in fully.
CAUTION: Take care not to damage axle
shaft oil seals.
60.Place a new joint washer in position on swivelpin
housing to stub axle mating face. Coat threads
of stub axle bolts with Loctite 270.
61.Fit stub axle with flat at 12 O'clock position.
CAUTION: Ensure that constant velocity
joint bearing journal is butted against
thrust ring on stub axle before stub axle is
secured.
62.Place mud shield in position and secure stub
axle to swivel pin housing with 6 bolts and
tighten evenly to
65 Nm (48 lbf/ft).
63.Fit brake jump hoses to brake jump hose
bracket.
64.Fit complete front hub assembly
See Repair,
Front hub assembly
.
65.Check swivel pin housing oil drain plug is fitted.
66.Fill swivel assembly to correct level, with new oil
See SECTION 10, Maintenance, Under
vehicle maintenance
.
NOTE: On later vehicles fill swivel pin
housing with 0.33 Litres of Molytex EP 00
grease.
67.Set steering lock stop bolts
See STEERING,
Adjustment, Steering lock stops
.

STEERING
1
FAULT DIAGNOSIS INSUFFICIENT POWER ASSISTANCE
1.Is fluid level correct?
YES - go to 3.
NO - Fill/bleed sytem
2.Is problem a leak?
YES - Diagnose
See Power Steering Fluid
Leaks
.
NO - continue
3.Is drive belt tension correct?
YES - go to 5.
NO - Is drive belt worn or contaminated with oil?
See ELECTRICAL, Repair, Auxiliary drive
belt
.
4.Is problem resolved?
YES - end
NO - continue
5.Carry out pressure test at idle and 1000 rev/min.
See Power Steering System - Test.
6.Is correct pressure achieved?
YES - steering box defective
Not at any speed go to 9.
Not at idle go to 7.
7.Is idle speed correct?
YES-Goto8.
NO - Correct idle speed -
See ENGINE TUNING
DATA, Information, 300 Tdi Engine
.
8.Is problem resolved?
YES - end
NO - go to 9.
9.Bypass steering box using adaptor tap
LRT-57-001
10.Is correct pressure obtained?
YES - defective steering box
NO - defective steering pump
CAUTION: Do not hold steering wheel on
full lock for more than 30 seconds in any
one minute to avoid overheating fluid and
possibly damaging seals.
NOTE: 1. Excessive pressure in the
system is almost always caused by a
faulty relief valve in the PAS pump.
NOTE: 2. Insufficient pressure in the
system is usually caused by low fluid level
or PAS pump drive belt slip, or one of the
following: PAS system leaks, faulty PAS pump
relief valve, fault in steering box valve and worm
assembly, leak at piston in steering box, worn
components in PAS pump or box.

57STEERING
4
FAULT DIAGNOSIS Symptom:-
Fluid leaks from steering box seals.
CAUTION: The steering wheel must not be
held on full lock for more than 30 seconds
in one minute, as this may overheat the
fluid and cause damage to the oil seals.
1.Check fluid level
See Repair, Power Steering
Fluid Reservoir
.
Check fluid pressure
See Power Steering
System - Test
.
2.Is pressure high?
YES - Renew pump
See Repair, Power
steering Pump
.
If oil seal leaks persist after renewing the pump
See Overhaul, Power Steering Box.
NO -
See Overhaul, Power Steering Box.
Symptom:-
Insufficient power assistance - castor return
action normal.
1.Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
.
YES - Continue.
2.Is fluid level correct?
NO - Check fluid level
See Repair, Power
Steering Fluid Reservoir
.
YES - Check system for air locks
See Repair,
Power Steering System - Bleed
.
3.Is pressure correct?
NO - Check fluid pressure
See Power Steering
System - Test
.
If pressure is not correct after bleeding the
system, renew pump
See Repair, Power
Steering Pump
.
YES -
See Overhaul, Power Steering Box.Symptom:-
Steering heavy - stiff, poor castor return action.
1.Are tyres correct type and pressure?
NO -
See INTRODUCTION, Information,
Wheels and Tyres
.
YES - Check universal joints for seizure and
correct alignment
See Repair, Lower Steering
Shaft and Universal Joints
.
Check power steering box adjustments
See
Overhaul, Power Steering Box
.
2.Is the power assistance satisfactory?
NO - See fault symptomInsufficient
assistance, (castor return action normal).
YES - Disconnect drag link from drop arm and
check steering column and box for stiffness
See
Repair, Drag Link and Drag Link Ends
.
3.Is the steering stiff with the drag link
disconnected?
NO - Check steering ball joints for seizure and
axle swivels lubrication and resistance
See
Repair, Drag Link and Drag Link Ends
,See
FRONT AXLE AND FINAL DRIVE, Overhaul,
Front Stub Axle, Constant Velocity Joint and
Swivel Pin Housing
.
YES - Disconnect the lower steering shaft and
check the column and box for stiffness
See
Repair, Lower Steering Shaft and Universal
Joints
.
4.Is the steering column stiff to turn when
disconnected from the box?
NO - Remove and overhaul box
See Overhaul,
Power Steering Box
.
YES - Adjust steering column
See Stiff
Steering Checklist
.