differential LAND ROVER DISCOVERY 1999 Repair Manual

TRANSFER BOX - LT230SE
41-64 OVERHAUL
Dog clutch - differential lock
$% 41.20.23
Disassembly
1.Remove 6 bolts securing high/low cross shaft
housing, multiplug bracket and selector cable
bracket to front output shaft housing; remove
brackets and housing.
2.Remove 7 bolts securing differential lock
selector side cover, remove side cover.3. Up to 03 Model Year: Note position of longest
bolt and remove 8 bolts securing front output
shaft housing to main casing and remove
housing.
4. Up to 03 Model Year: Remove 3 bolts securing
differential lock selector housing and remove
housing.
5. Up to 03 Model Year: Remove and discard 'O'
rings from selector housing.
6. Up to 03 Model Year: Remove differential
warning lamp switch and locknut.
7. Up to 03 Model Year: Remove Allen plug and
remove differential lock detent spring and ball.
8. 03 Model Year onwards: Remove 2
differential warning lamp switches and sealing
washers.

TRANSFER BOX - LT230SE
OVERHAUL 41-65
9. 03 Model Year onwards:Note position of
longest bolt and remove 8 bolts securing front
output shaft housing to main casing; remove
housing.
10. 03 Model Year onwards:Remove 3 bolts
securing differential lock selector housing and
bracket, remove housing.
11. 03 Model Year onwards:Remove and discard
'O' rings from selector housing.
12. 03 Model Year onwards:Remove differential
lock detent plug, recover spring and ball.
13.Compress differential lock selector fork spring
and remove retaining clips from each end of
spring.
14.Withdraw differential lock selector shaft from
front output housing, recover spring and
remove selector fork.
15.Position tool LRT-51-003 to output shaft drive
flange, remove and discard nut. 16.Remove and discard steel and felt washers.
Remove output shaft drive flange.
17.Using a copper mallet, drive output shaft from
housing.
18.Noting its fitted position, remove bearing
spacer from output shaft.
19.Noting its fitted position, remove dog clutch
from output shaft.
20.Remove and discard oil seal from housing.
Reassembly
1.Clean differential lock components. Remove all
traces of sealant from mating faces of
housings, side cover, bolt threads, detent plugs
and differential lock warning lamp switches.
2.Lubricate components with gearbox oil.
3.Using tool LRT-41-012, fit new output shaft oil
seal.
CAUTION: Oil seal must be fitted dry.

TRANSFER BOX - LT230SE
41-66 OVERHAUL
4.Fit bearing spacer to output shaft with chamfer
on spacer towards threaded end.
5.Fit dog clutch with flange on clutch facing
towards splined end.
6.Using a copper mallet, drive output shaft into
bearing.
7.Compress differential lock selector spring and
fit selector fork.
8.Position selector fork to groove in dog clutch.
9.Fit differential lock selector shaft and locate in
housing recess, rotate shaft until the two flats
for retaining clips are at right angles to the
cover plate mating face.
10.Compress differential lock selector spring and
fit retaining clips at each end of spring.
CAUTION: Ensure ends of spring are fully
seated in recess in clips.
11.Apply sealant, Part No. STC 4600 to front
output shaft housing.
12.Position housing ensuring that output shaft and
dog clutch splines are correctly engaged.
13.Apply sealant, Part No. STC 50552 to threads
of bolts.
14.Fit front output shaft housing bolts and tighten
in a diagonal sequence to 45 Nm (33 lbf.ft).
15.Apply sealant, Part No. STC 4600 to mating
face of high/low selector housing.
16.Position high/low selector housing to front
output housing ensuring that high/low selector
finger is located in groove in selector shaft.
17. Position multiplug and selector cable brackets
to high/low selector housing
18.Apply sealant, Part No. STC 50552 to threads
of high/low selector housing bolts.
19.Fit bolts and tighten to 25 Nm (18 lbf.ft).20.Fit differential lock detent ball and spring.
21. Up to 03 Model Year: Apply sealant, Part No.
STC 50552 to threads of detent plug.
22. Up to 03 Model Year: Fit and tighten detent
plug, then unscrew 2 complete turns.
23. 03 Model Year onwards: Apply sealant, Part
No. STC 50552 to threads of differential lock
detent plug.
24.Fit differential lock detent ball and spring.
25.Fit detent plug and tighten until head of plug is
level with face of housing.
26.Using a suitable straight edge, check that head
of plug is correctly positioned, screw plug in or
out as necessary.
27.Lubricate and fit new 'O' rings to differential lock
selector housing.
28.Fit selector housing, ensure selector finger is
located in shaft recess.
29.Position bracket to selector housing.
30.Apply sealant, Part No. STC 50552 to threads
of selector housing bolts, fit bolts and tighten to
25 Nm (18 lbf.ft).
M41 7886

TRANSFER BOX - LT230SE
OVERHAUL 41-67
31.Clean threads of differential lock warning lamp
switch(es).
32. Uo to 03 Model year: Fit nut to switch head
with counterbore positioned towards switch
head. The nut acts as a spacer to ensure
that switch setting is correct. Always
ensure that nut is fully tightened to switch
head (no gap).
33. Uo to 03 Model year: Apply sealant, Part No.
STC 50552 to threads of differential warning
lamp switch.
34. Uo to 03 Model year: Position switch into front
output housing until nut bottoms out on
housing, tighten nut to 11 Nm (8 lbf.ft).
35. 03 Model Year onwards: Fit new aluminium
sealing washers to differential lock warning
lamp switches.
CAUTION: Ensure that replacement
washers are the same thickness as the
originals.
36. 03 Model Year onwards: Apply sealant, Part
No. STC 50552 to threads of both switches.
37. 03 Model Year onwards: Fit switches and
tighten to 25 Nm (18 lbf.ft).
38. If fitted: Operate differential lock selector lever
and check that detent ball can be felt to
positively engage/disengage with grooves in
shaft.
39. Up to 03 Model Year: Screw plug in or out until
setting is correct
40.Apply sealant, Part No. STC 4600 to mating
face of differential lock selector side cover.
41.Apply sealant, Part No. STC 50552 to threads
of side cover bolts.
42.Position differential lock selector side cover to
front output shaft housing, fit bolts and tighten
25 Nm (18 lbf.ft).43.Fit output flange, new felt and steel washers
and new retaining nut.
44.Using tool LRT-51-003 to restrain flange,
tighten output flange nut to 162 Nm (119 lbf.ft).

TRANSFER BOX - LT230SE
41-70 OVERHAUL
7.Position dial gauge with stylus contacting input
gear, push input gear rearwards and zero
gauge.
8.Push input gear forwards and note gauge
reading.
9.Calculate thickness of shim required using the
formula - A+B+C=D where:
lA= Thickness of installed shim - 3.15 mm
(0.12 in)
lB= Recorded end-float.
lC= Required pre-load - 0.05 mm (0.002 in).
lD= Thickness of shim required.
10.If an alternative shim is required to establish
correct pre-load, fit an alternative shim. Shims
are available from 3.15 to 4.00 mm (0.12 to
0.16 in) thickness, in increments of 0.05 mm
(0.002 in).
11.Remove 2 bolts, remove bearing housing and
input gear.
12.Lubricate input gear and bearings with
recommended oil.
13.Position input gear into main casing.
14.Apply sealant, Part No. STC 4600to bearing
housing and cover.
15.Apply sealant, Part No. STC 50552 to threads
of cover bolts and stud nut.
16.Position bearing housing/cover, align reference
marks and tighten bolts and stud nut by
diagonal selection to 45 Nm (33 lbf.ft).
17.Using tool LRT-37-014 fit new input shaft oil
seal.
CAUTION: Oil seal must be fitted dry.
Low gear - differential
$% 41.20.62
Disassembly
1.Remove differential.

+ TRANSFER BOX - LT230SE,
OVERHAUL, Dog clutch - differential lock.
2.Secure differential in a soft jawed vice.
3.Release staking from bearing retaining nut.
4.Using tool LRT-41-007 remove and discard
bearing retaining nut.
5.Position tool LRT-99-002. to a vice.
6.Position tool LRT-41-001 around rear
differential bearing, position differential to tool
LRT-99-002 and press off bearing.

TRANSFER BOX - LT230SE
OVERHAUL 41-71
7.Remove high range gear and bush.
8.Make suitable alignment marks between high/
low selector sleeve and hub, remove selector
sleeve. 9.Using a suitable press and thrust button LRT-
41-001remove high/low hub and low range
gear.
Reassembly
1.Clean differential components.
2.Lubricate components with gearbox oil.
3.Fit differential in soft jawed vice, and fit low
range gear with dog teeth facing uppermost.
4.Fit high/low hub ensuring that machined
groove on hub teeth faces towards low range
gear.
5.Fit high/low selector sleeve ensuring that
alignment marks on hub and sleeve are
together.
6.Fit bush to high range gear ensuring collar is
uppermost.
7.Fit high range gear and bush onto shaft.

TRANSFER BOX - LT230SE
41-72 OVERHAUL
8.Fit rear bearing using tool LRT-41-008.
9.Fit new bearing retaining nut and using tool
LRT-41-007, tighten to 72 Nm (53 lbf.ft).
CAUTION: Ensure that threads of nut are
'Patched.'
10.Using a suitable drift, stake collar of nut into
differential shaft recess.
11.Fit differential.

+ TRANSFER BOX - LT230SE,
OVERHAUL, Differential assembly.

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-28 REPAIRS
15.Remove handbrake drum retaining screw and
remove brake drum.
16.Remove 4 bolts from handbrake back plate,
release back plate and tie aside.
17. Models fitted with high/low shift interlock
solenoid: Release interlock solenoid multiplug
and disconnect multiplug from main harness.
18. Models fitted with high/low shift interlock
solenoid: Remove sleeve retaining rings and
remove sleeve from high/low selector cable.
19. If fitted Remove and discard clevis pin
securing differential lock selector cable to
transfer gearbox.20. If fitted Loosen locknuts securing differential
lock selector cable to differential lock selector
cable abutment bracket.
21. If fitted Release and remove differential lock
selector cable from differential lock selector
cable abutment bracket.
22.Remove clevis pin securing high/low ratio
selector cable to selector lever, remove 'C' clip
and remove outer cable from abutment
bracket.
23. Up to 03 Model Year - If fitted: Disconnect
from differential lock warning lamp switch and
multiplugs from high/low ratio switch and
neutral sensor.

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-29
24. 03 Model Year onwards - If fitted: Release
and disconnect both differential lock warning
lamp switch multiplugs from main harness.
25.Remove cable tie and multiplug from bracket
on transfer box.
26.Release transfer and automatic gearbox
breather pipes from clip at rear of cylinder
block.
27.Position gearbox support jack and secure tool
LRT-99-008A to support plate on jack. 28.Position a second support jack under engine
using a block between engine sump and jack
to prevent damage to sump.
29.Remove 4 bolts and nut, remove engine LH
rear mounting.
30.Remove 4 bolts and nut, remove engine RH
rear mounting.
31.Remove 2 bolts securing gearbox oil cooler
pipe clips to engine sump and alternator
mounting bracket.

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-31
40.Fit suitable strap to retain torque converter.
Refit
1.Clean gearbox to engine mating faces.
2.Remove torque converter retaining strap.
3.With assistance position gearbox to engine.
4.Fit but do not tighten six bolts securing gearbox
housing to engine.
5.Connect multiplug to gearbox and tighten
locking ring.
6.Connect multiplug to inhibitor switch.
7. If fitted: Connect and adjust differential lock
selector cable.

+ TRANSFER BOX - LT230SE,
ADJUSTMENTS, Cable - selector -
differential lock - adjust.
8.Position selector lever to inhibitor switch and
tighten nut to 25 Nm (18 lbf.ft).
9.Position selector cable to gearbox and secure
with 'C' clip.
10.Clean oil pipe unions and fit new 'O' rings.
11.Position and tighten pipe unions to gearbox.
12.Position and tighten oil cooler pipe clamps.
13.Position and tighten oil cooler pipe clips to
engine sump and alternator bracket.
14.Position engine RH and LH rear mountings
and tighten bolts to 85 Nm (63 lbf.ft) and nuts to
85 Nm (63 lbf.ft).
15.Secure gearbox breather pipes to bulkhead
clip.
16. Up to 03 Model Year - If fitted: Connect 2
Lucars to differential lock warning lamp switch
and multiplugs to high/low ratio switch and
neutral sensor.
17. 03 Model Year onwards - If fitted: Connect
differential lock warning lamp switch multiplugs
to main harness.
18.Position cable tie and multiplug to transfer box
bracket.
19.Connect high/low ratio selector cable to
selector lever and secure with clevis pin. 20.Position high/low ratio selector cable to
abutment bracket and secure with 'C' clip.
21. Models fitted with high/low shift interlock
solenoid: Position interlock solenoid harness
to high/low shift cable, fit sleeve around cable
and harness.
22. Models fitted with high/low shift interlock
solenoid: Connect solenoid multiplug to main
harness and secure multiplug to bracket.
23.Position handbrake backplate and tighten bolts
to 75 Nm (55 lbf.ft).
24.Fit hand brake drum and tighten screw.
25.Remove bolts securing tool LRT-99-008A to
gearbox.
26.Rotate engine to align torque converter, fit new
bolts and tighten to 50 Nm (37 lbf.ft).
27.Fit rear propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.
28.Fit front propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
29.Fill transfer gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
30.Fill automatic gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
31.Position intermediate silencer and secure to
mounting rubbers.
32.Clean silencer and tail pipe mating faces.
33.Position new gasket to tail pipe and tighten
nuts to 25 Nm (18 lbf.ft).
34.Fit exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - Td5, REPAIRS, Pipe - front.
35.Fit bolt securing closing plate to gearbox
housing and tighten to 7 Nm (5.2 lbf.ft).
36.Fit upper bolts securing gearbox housing to
engine and tighten to 50 Nm (37 lbf.ft).
37.Fit starter motor.

+ CHARGING AND STARTING,
REPAIRS, Starter motor - diesel.
38.Tighten remaining gearbox housing to engine
bolts to 50 Nm (37 lbf.ft).
39.Connect battery earth lead.
40.Fit battery cover and secure with fixings.
41.Check and adjust selector cable.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, ADJUSTMENTS, Cable - selector.