LAND ROVER DISCOVERY 2002 Workshop Manual

TRANSFER BOX - LT230SE
41-58 OVERHAUL
10.Position tool LRT-51-003 to output shaft drive
flange, remove and discard nut.
11.Remove and discard steel and felt washers.
Remove output shaft drive flange.
12.Using a copper mallet, drive output shaft from
housing.
13.Noting its fitted position, remove bearing
spacer from output shaft.
14.Noting its fitted position, remove dog clutch
from output shaft.
15.Remove and discard oil seal from housing. Reassembly
1.Clean differential lock components.
2.Lubricate components with gearbox oil.
3.Using tool LRT-41-012, fit new output shaft oil
seal.
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 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 selector spring and fit retaining clips
at each end of spring.
CAUTION: Ensure ends of spring are fully
seated in recess in clips.
11.Fit detent ball and spring.
12.Apply Loctite 290 to threads of detent plug.
13.Fit and tighten detent plug, then unscrew 2
complete turns.
14.Fit new 'O' ring to differential lock selector
housing.
15.Fit selector housing, ensure selector finger is
located in shaft recess.
16.Apply Loctite 290 to threads of bolts and tighten
selector housing bolts to 25 Nm (18 lbf.ft).
17.Apply sealant, Part No. STC 3254 to front
output shaft housing.
18.Position housing ensuring that output shaft and
dog clutch splines are correctly engaged.
19.Apply Loctite 290 to threads of bolts.
20.Fit front output shaft housing bolts and tighten
in a diagonal sequence to 45 Nm (33 lbf.ft).

TRANSFER BOX - LT230SE
OVERHAUL 41-59
21.Clean threads of differential lock warning lamp
switch(es).
22.Up to 03 MY: 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).
23.Apply Hylomar PL 32 sealant to threads of
differential warning lamp switch(es).
24.Up to 03 MY: Position switch into front output
housing until nut bottoms out on housing,
tighten nut to 11 Nm (8 lbf.ft).
25.03 MY onwards: Fit new sealing washers to
switches, fir switches to front output housing
and tighten to 25 Nm (18 lbf.ft).
26.Operate differential lock selector lever and
check that detent ball can be felt to positively
engage/disengage with grooves in shaft.
Screw plug in or out until setting is correct.27.Fit output flange, new felt and steel washers
and new retaining nut.
28.Using tool LRT-51-003 to restrain flange,
tighten output flange nut to 162 Nm (119 lbf.ft).

TRANSFER BOX - LT230SE
41-60 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 41-61
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
41-62 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 3254 to bearing
housing and cover.
15.Position bearing housing/cover, align reference
marks and tighten by diagonal selection to 45
Nm (33 lbf.ft).
16.Using tool LRT-37-014 fit new input shaft oil
seal.
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 41-63
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
41-64 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).
10.Using a suitable drift, stake collar of nut into
differential shaft recess.
11.Fit high/low selector shaft detent ball and
spring.
12.Apply Loctite 290 sealant to threads of detent
plug.
13.Fit and tighten plug, then loosen 2 complete
turns.
14.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 switch
5Oil 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