differential LAND ROVER DISCOVERY 1999 Manual Online

REAR AXLE
51-6 REPAIRS
10.Release and remove wheel hubs and drive
shafts from rear axle. Remove and discard 'O'
rings from wheel hubs.
11.Remove 10 bolts securing differential to axle.
Release and remove differential from axle. Refit
1.Clean drive shafts, wheel hubs and wheel hub
locations in rear axle.
2.Using a suitable solvent, remove all traces
sealant from differential and axle mating faces.
3.Apply sealant, Part No. STC 3811 to differential
or axle mating face.
4.Apply sealant, Part No. STC 50552 to threads
of differential securing bolts.
5.Fit differential to axle, fit bolts and tighten to 55
Nm (41 lbf.ft).
6.Clean pinion flange and centralising peg.
7.Using a tubular drift, fit centralising peg to
pinion flange. Ensure that the large diameter
part of the centralising peg is below pinion
flange mounting surface.
8.Position propeller shaft and align reference
marks.
9.Fit nuts and bolts securing flexible coupling to
pinion flange and tighten to 76 Nm (56 lbf.ft)
10.Lubricate 2 new wheel hub 'O' rings with clean
differential oil.

+ CAPACITIES, FLUIDS,
LUBRICANTS AND SEALANTS,
Lubrication. Install 'O' rings on wheel hubs.
11.Fit LH and RH drive shafts and wheel hubs to
rear axle. Fit wheel hub bolts and tighten to 100
Nm (74 lbf.ft).
12.Connect each ABS sensor multiplug and
secure harness to harness bracket and brake
hose.
13.Fit LH and RH rear brake discs.

+ BRAKES, REPAIRS, Brake disc -
rear.
14.Remove stand(s) and lower vehicle.
15.Fill differential with oil.

+ MAINTENANCE, PROCEDURES,
Front and rear axle.
M51 0042B

REAR AXLE
REPAIRS 51-7
Seal - differential pinion
$% 51.20.01
Remove
1.Raise rear of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Reference mark rear propeller shaft for
reassembly.
3.Remove 3 nuts and bolts securing flexible
coupling to pinion flange. Tie propeller shaft
aside.
4.Using tool LRT-51-008, extract the centralising
peg from the pinion flange. Remove the
centralising peg from the tool.5.Using tool LRT-51-003 to restrain pinion
flange, remove bolt and washer securing pinion
flange. Remove pinion flange.
6.Position container to catch oil spillage
7.Using a suitable lever, remove pinion oil seal.
Take care to avoid damage to oil seal
recess.
M51 0043A
2
3
M51 0056
LRT-51-008
M51 0047A
LRT-51-003

REAR AXLE
51-8 REPAIRS
Refit
1.Clean pinion oil seal recess and pinion flange.
2.Lubricate oil seal lip with clean differential oil.

+ CAPACITIES, FLUIDS,
LUBRICANTS AND SEALANTS,
Lubrication.
3.Using tool LRT-51-010, fit pinion oil seal.
4.Fit pinion flange and securing bolt and washer.
Using tool LRT-51-003 to restrain pinion
flange, tighten pinion flange securing bolt to
100 Nm (74 lbf.ft).
5.Using a tubular drift, fit centralising peg to
pinion flange. Ensure that large diameter part of
centralising peg is below pinion flange
mounting surface.
6.Position propeller shaft and align reference
marks.
7.Fit nuts and bolts securing flexible coupling to
pinion flange and tighten to 76 Nm (55 lbf.ft).
8.Remove stand(s) and lower vehicle.
9.Check differential oil level.

+ MAINTENANCE, PROCEDURES,
Front and rear axle.
M51 0047A
LRT-51-003

REAR AXLE
OVERHAUL 51-9
OVERHAUL
Differential assembly
$% 51.15.07
Disassembly
1.Remove differential assembly.
2.Secure differential assembly in a vice or stand.
3.Remove roll pins securing adjusting nuts, using
LRT 51-018-5 loosen adjusting nuts.
4.Reference mark bearing caps to aid assembly.
5.Remove bolts securing bearing caps and
remove caps.6.Remove crown wheel assembly and collect
bearing outer races.
7.Mark outer races to bearings to aid assembly.
8.Using LRT-51-003 to restrain pinion flange
remove bolt and collect washer.

REAR AXLE
51-10 OVERHAUL
9.Remove pinion flange
NOTE: Older front differentials have a square
flange and an extra spacer fitted, this spacer
must be removed. Later front differentials have
a round flange but no spacer fitted.
10.Using a lever, remove pinion oil seal.
CAUTION: Take care to avoid damage to oil
seal recess.
11.Carefully tap pinion from bearings and collect
tail bearing.
12.Remove pinion tail bearing shim and record
shim size.13.Using a bearing puller, remove pinion head
bearing.
14.Remove pinion bearing races.
15.Remove pinion head bearing shim and record
shim size.

REAR AXLE
OVERHAUL 51-11
16.Using a two legged puller and LRT 51-018/6,
remove the differential bearings.
17.Secure the crown wheel assembly in a vice.
18.Remove and discard 10 bolts securing the
crown wheel to carrier.
19.Carefully remove the crown wheel from the
carrier.20.Remove and discard roll pin securing carrier
cross shaft and remove cross shaft.
21.Rotate gears to the open part of carrier and
remove planet gears.
22.Remove sun gears.

REAR AXLE
OVERHAUL 51-13
21. Pinion height setting procedure:
l'A' = Nominal pinion height setting, 74.390.
l'B' = Setting block height.
l'C' = Head height setting.
l'C' = 'A' - 'B'. Subtract nominal pinion height
'A' from setting block height 'B' (on side of
setting block).
lExample: 74.390 - 73.130 = 1.26 mm
(2.929' - 2.88' = 0.049'). Therefore pinion
head height reading is 1.260 mm ± 0.025
mm (0.049' ± 0.001').
CAUTION: Setting block height must be
checked using figures on side of block.
22.Align setting gauge LRT-51-018/7 to setting
block, rock gauge to obtain minimum reading. If
reading is lower than required reading,
decrease shim size. If reading is higher than
required reading, increase shim size.
23.Using LRT-51-003 to restrain pinion flange,
remove bolt and washer. Remove pinion
flange.
24.Remove pinion, collect tail bearing and tail
bearing shim.
25.Remove pinion head bearing outer race and
shim. Discard shim. Ensure bearing race
recess is clean and free from burrs.26.Fit calculated shim, and using LRT-51-018/4 fit
head bearing outer race.
27.Fit pinion, pinion tail bearing and tail bearing
shim.
28.Fit pinion flange and bolt and washer. Using
LRT-51-003 to restrain pinion flange, tighten
bolt to 100 Nm (74 lbf.ft).
29.Rotate pinion in both directions to settle
bearings.
30.Recheck pinion Torque to Turn, adjust if
necessary.
31.Recheck pinion head height.
32.Using LRT-51-003 to restrain pinion flange,
remove bolt and washer. Remove pinion
flange.
33.Discard bolt.
34.Using LRT-51-010 fit pinion seal.
35.Ensure spacer and tail bearing are correctly
located.
36.Fit pinion, pinion flange and washer.
37.Fit new pinion flange bolt and tighten to 100 Nm
(74 lbf.ft).
38.Lightly oil differential bearings.
39.Ensure spring dowels are fitted in bearing caps.
40.Fit differential bearing outer races and locate
differential assembly into housing.
41.Fit bearing caps and tighten bolts to 10 Nm (7.5
lbf.ft).

REAR AXLE
51-14 OVERHAUL
42.Fit adjusting nuts, tighten crown wheel side nut
to 22 Nm (16 lbf.ft). Ensure opposing nut is
loose.
43.Position DTI to check crown wheel backlash.
Adjust opposing nut to obtain correct crown
wheel backlash.
44.Rotate pinion in both directions to settle
bearings.
45.Measure in 3 places to obtain correct crown
wheel backlash.
NOTE: Crown wheel backlash should be within
0.076 mm - 0.177 mm (0.003' - 0.007').
46.Align adjusting nuts to next roll pin slot, do not
loosen nuts to align slots.
47.Tighten bearing cap bolts to 90 Nm (66.5 lbf.ft).
48.Secure adjusting nuts with new roll pins.
49.Apply Prussian Blue to crown wheel teeth to
check tooth contact.50.Rotate pinion several times to obtain full tooth
contact.
51.A = Normal pattern, the drive pattern should be
centred on the gear teeth. The coast pattern
should be centred on the gear teeth but may be
towards the toe. There should be some
clearance between the pattern and the top of
the gear teeth.
52.B = Backlash correct, thinner pinion shim
required.
53.C = Backlash correct, thicker pinion shim
required.
54.D = Pinion shim correct, decrease backlash.
55.E = Pinion shim correct, increase backlash.
56.Note assembly Torque to Turn when checking
tooth contact. Total Torque to Turn should not
exceed 10.85 Nm (8 lbf.ft).
Reassembly
1.Fit differential assembly.

FRONT AXLE
DESCRIPTION AND OPERATION 54-1
FRONT AXLE DESCRIPTION AND OPERAT ION
Front axle component layout
1Stake nut
2Hub flange
3Hub bearing
4Steering knuckle
5Drive shaft
6Oil seal
7Bolt
8Bolt
9Washer10Drive flange
11Oil seal
12Differential unit
13Drain plug
14Axle casing
15Breather tube
16Oil level plug
17'O' ring

FRONT AXLE
54-2 DESCRIPTION AND OPERATION
Description
General
The front axle consists of an axle casing with a differential unit attached to the right of the vehicle centre line. A wheel
hub is installed in a steering knuckle at each end of the axle casing and connected to the differential unit by a drive
shaft.
Axle casing
The axle casing is of welded construction, with brackets on the casing exterior for attachment to the front suspension.
Yokes at each end of the casing incorporate upper and lower ball joints for attachment of the steering knuckles.
A differential cover on the front of the axle casing contains an oil level plug for checking and replenishment of the
differential lubricating oil. A magnetic drain plug is installed on the underside of the casing. An oil seal is installed in
each end of the axle casing to prevent leakage past the drive shafts.
The interior of the axle casing is ventilated through a breather tube inserted in a red plastic sleeve in the top of the
casing. The open end of the breather tube is located in the left rear corner of the engine compartment.
Differential unit
The differential unit is of the spiral bevel type, lubricated by splash oil. The unit consists of a differential carrier
attached to a pinion housing. In the pinion housing, the pinion is splined to a drive flange which is secured with a bolt
and washer. An oil seal prevents leakage past the drive flange.
Steering knuckle
The steering knuckles are mounted on upper and lower ball joints in the yokes at the end of the axle casing. A tension
collet, in the lower mounting point of each steering knuckle, accommodates manufacturing tolerances to enable the
correct tightening of both ball joints. Lugs are incorporated on the steering knuckles for attachment of the steering
system drag link and track rod.