2002 LAND ROVER DISCOVERY gearbox

TRANSFER BOX - LT230SE
REPAIRS 41-35
3.Fit new seal using tool LRT-41-012.
4.Position drive flange, fit new felt and steel
washers.
5.Position tool LRT-51-003 and tighten new
drive flange nut to 148 Nm (109 lbf.ft).
6.Position handbrake drum and tighten screw.
7.Tighten brake shoe adjuster bolt to 25 Nm (18
lbf.ft) then loosen one and a half turns.
8.Check that brake drum is free to rotate.
9.Fit propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
10.Top-up transfer box oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
Gasket - rear output shaft housing
$% 41.20.55
Remove
1.Drain transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
2.Remove rear output shaft seal.

+ TRANSFER BOX - LT230SE,
REPAIRS, Seal - rear output shaft.
3.Mark output shaft housing to main casing for
assembly purposes.
4.Note position of shoulder bolt, remove 6 bolts
securing housing to main casing.
Refit
1.Clean output shaft housing, mating face on
main casing and sealant from bolt threads.
2.Apply sealant, Part No. STC 3254 to mating
flange on output shaft housing.
3.Fit output shaft housing to main casing.
4.Apply Loctite 290 to bolt threads.
5.Fit output shaft housing bolts and tighten by
diagonal selection to 45 Nm (33 lbf.ft).
6.Fit rear output shaft seal.

+ TRANSFER BOX - LT230SE,
REPAIRS, Seal - rear output shaft.
7.Fill transfer gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.

TRANSFER BOX - LT230SE
41-52 OVERHAUL
Refit
1.Clean differential components.
2.Lubricate components with gearbox oil.
3.Position differential in soft jawed vice and fit
front bearing using tool LRT-41-008.
4.Invert differential in soft jawed vice, and fit low
range gear with dog teeth facing uppermost. 5.Fit high/low hub ensuring that machined
groove on hub teeth faces towards low range
gear.
6.Fit high/low selector sleeve ensuring that
alignment marks on hub and sleeve are
together.
7.Fit bush to high range gear ensuring collar is
uppermost.
8.Fit high range gear and bush onto shaft.
9.Fit new rear bearing using tool LRT-41-008.
10.Using tool LRT-41-007, fit new bearing
retaining nut and tighten to 72 Nm (53 lbf.ft).
Do not stake nut at this stage.

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 41-63
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.

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

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-4 DESCRIPTION AND OPERATION
Description
General
The automatic gearbox is a four speed unit with electronic control of gear selection, shift quality and torque converter
lock-up. Selections on the selector lever assembly are transmitted to the gearbox by a selector cable. A gear position
switch on the gearbox transmits the gear selection to an Electronic Automatic Transmission (EAT) ECU, which
outputs the appropriate control signals to an electro-hydraulic valve block in the gearbox. A mode switch enables the
driver to change the control mode of the EAT ECU. The EAT ECU operates warning lamps in the instrument pack to
indicate the control mode and system status.
The gearbox features a pressure lubrication system and is cooled by pumping the lubricant through an oil cooler.
On NAS market vehicles from 03 model year, the ZF 4HP24 transmission unit is introduced for use with the 4.6 litre
V8 engine. This transmission is required to accomodate the increased power output of the larger engine. The ZF
4HP22 transmission remains in use on vehicles with Td5 and 4.0 litre V8 engines.
Both transmission units are of similar construction, with the ZF 4HP24 unit being 15 mm longer than the 4HP22 unit
to accomodate a larger fluid pump. The operation of both transmission units is the same.
Selector lever assembly