LAND ROVER DISCOVERY 1999 Workshop Manual

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
41-68 OVERHAUL
Input gear/bearing
$% 41.20.60
Disassembly
1.Make alignment marks between cover plate/
bearing housing and main casing.
2.Remove 5 bolts and stud nut securing cover/
bearing housing to main casing. Remove cover
and bearing housing.
3.Remove input gear assembly. 4.Remove and discard oil seal from main casing.
5.Drift out bearing track from main casing.

TRANSFER BOX - LT230SE
OVERHAUL 41-69
6.Drift out bearing track from housing and collect
selective shim.
7.Position tool LRT-99-002 to vice.
8.Assemble tool LRT-41-003 to bearing, position
input gear to hand press and remove bearing.
9.Repeat procedure for remaining bearing. Reassembly
1.Clean input gear, cover/bearing housing and
main casing.
2.Using tool LRT-99-002 and LRT-41-003 fit
new bearings to input gear.
3.Using a suitable mandrel, fit bearing track to
main casing.
4.Fit a 3.15 mm (0.12 in) thick shim to bearing
housing and using a suitable mandrel fit
bearing track to housing.
5.Position input gear to main casing.
6.Fit bearing housing, ensuring reference marks
are aligned, secure bearing housing with 2
bolts and tighten to 25 Nm (18 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
DESCRIPTION AND OPERATION 44-1
AUTOMATIC GE ARBOX - ZF4HP22 - 24 DESCRIPTION AND OPERAT ION
Automatic gearbox component layout
1Selector lever assembly
2Gearbox
3Electronic automatic transmission ECU
4Selector position switch5Oil cooler
6Fluid lines
7Breather tube
8Selector cable

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-2 DESCRIPTION AND OPERATION
Control schematic

AUTOMATIC GEARBOX - ZF4HP22 - 24
DESCRIPTION AND OPERATION 44-3
1Transmission high/low switch
2Mode switch
3Gear position switch connector
4Solenoid valve/speed sensor connector
5Electronic automatic transmission ECU
6Engine control module
7Diagnostic socket
8Instrument pack
9Transmission fluid temperature sensor
10Body control unit
11Battery power supply
12Ignition power supply