1999 LAND ROVER DISCOVERY clutch

TRANSFER BOX - LT230SE
DESCRIPTION AND OPERATION 41-11
1Breather pipe, banjo bolt and sealing washers
2Bolt - high/low cross shaft housing and
abutment bracket
3Selector cable abutment bracket
4Multiplug bracket
5Hollow plug
6High/low cross shaft housing
7'O' ring
8High/low cross shaft and lever
9Front output shaft
10Dog clutch - Differential lock
11Warning lamp switch - Differential lock
12Warning lamp switch - Differential lock
13Aluminium sealing washers
14Selector shaft - Differential lock
15Aluminium sealing washer
16Front output housing
17Spring and clips - Differential lock
18Bolt - cover plate
19Cover plate
20Selector fork - Differential lock
21Bolt - front output housing22Detent plug - Differential lock
23Detent spring - Differential lock
24Detent ball - Differential lock
25Hollow plug
26Circlip
27Front output flange
28Steel washer
29Self-locking nut
30Felt washer
31Oil seal
32Output shaft bearing
33Bearing spacer
34High/low detect switch
35Selector finger and shaft - Differential lock
36'O' rings - Differential lock
37Bolt - selector housing - Differential lock
38Selector housing - Differential lock
39High/low selector finger
40Washer
41Nut
42Differential lock selector lever

TRANSFER BOX - LT230SE
41-14 DESCRIPTION AND OPERATION
Mainshaft input gear
The gearbox output shaft is splined into the mainshaft input gear which is supported by taper roller bearings.
Input gear bearing pre-load is achieved by the use of a selective shim located in the bearing housing.
Intermediate gears
The intermediate gear cluster is supported by the taper roller bearings located at each end of the cluster and runs on
the intermediate shaft which, in turn, is supported at the front and rear by the main casing.
A selective spacer, positioned between the gears, pre-loads the intermediate gear bearings when the intermediate
shaft nut is tightened sufficiently to achieve the correct 'torque to turn' of the intermediate gears.
On vehicles from 03 model year, the circlips used to retain the bearings in the intermediate gear are deleted. The bore
of the intermediate gear is machined with a shoulder at each end to locate the bearings.
Differential assembly
The differential assembly is supported at the front and rear by taper roller bearings, the front bearing outer track is
located in the front output housing and the rear bearing outer track is located in the main casing by the rear output
housing. Bearing pre-load is achieved by means of a selective shim located in the front output housing.
The differential rear shaft carries the low range gear, high/low selector sleeve and hub, high range gear and bush and
the differential rear bearing; these components being secured to the shaft by a special staked nut.
The differential assembly comprises front and rear half carriers with integral shafts and with sun and planet gears
mounted on cross shafts within the half carriers. Dished, non-selective thrust washers control the engagement of the
planet gears with the sun gears, whilst selective thrust washers are used to control engagement of the sun gears and
'torque to turn' of the differential. The differential carrier halves are bolted together, a retaining ring providing positive
location of the cross shafts.
The high/low selector shaft and fork are located at the side of the differential, movement of the shaft, fork and selector
sleeve being controlled by the high/low selector finger. A spring loaded detent ball fitted in the main casing, locates
in grooves in the shaft.
On vehicles from 03 model year, the selector fork is modified and fitted with a spring assister and clips to reduce the
effort required to move the selector lever.
Front output housing
The front output housing carries the front output shaft and flange, high/low cross shaft, housing and selector and on
certain vehicles, the differential lock selector shaft and fork.
The front output shaft is supported in the housing by a single bearing and is splined into the differential front sun gear.
High/low selector
The high/low cross shaft is located in a housing bolted to the top of the output housing and is connected to the high/
low selector finger which locates in a slot in the selector shaft.
High/low detect switch
A high/low detect switch is fitted in the front output housing and connects to earth when low is selected. The switch is
connected to the engine ECM, the SLABS ECU and the EAT ECU. The purpose of the switch is to enable selection
of the hill descent feature and to modify the engine fuelling and automatic gearbox gearshift maps stored within the
respective ECM's and ECU's.
Differential lock - If fitted
The differential lock selector housing is bolted to the top of the front output housing, the selector finger passes through
the housing, locating in a slot in the differential lock selector shaft. The differential lock selector shaft passes through
the selector fork which is located beneath a plate bolted to the side of the output housing. The selector fork engages
the dog clutch sleeve with the differential rear shaft when the splines of the sleeve and differential rear shaft are
aligned. A spring loaded detent ball fitted in the output housing locates in grooves in the shaft.

TRANSFER BOX - LT230SE
41-48 OVERHAUL
15.Position tool LRT-51-003 to output shaft drive
flange, remove and discard nut, steel and felt
washers; remove output shaft drive flange.
16.Using a copper mallet, drive output shaft from
housing, recover bearing spacer.
17. If fitted: Noting its fitted position, remove dog
clutch from output shaft. 18.Remove and discard oil seal from housing.
19.Remove and discard circlip retaining output
shaft bearing.
20.Support housing and drift out output shaft
bearing.
21.Remove and discard differential bearing track
and collect selective shim.

TRANSFER BOX - LT230SE
OVERHAUL 41-53
11.Check differential lock selector fork for cracks
and wear.
12.Check selector fork finger width.
lFinger width = 7.92 to 7.97 mm (0.311 to
0.313 in).
13.Check differential lock selector fork clips for
wear and damage. Check spring for distortion
and free length.
lSpring free length = 84.58 mm (3.33 in).
14.Check dog clutch internal teeth and grooves
and teeth on output shaft for wear and
damage. Check selector fork groove width.
lGroove width = 8.05 to 8.20 mm (0.32 to
0.33 in).
15.Carry out the following inspection procedures
for all transfer boxes.
16.Check threads and splines of output shaft for
damage and wear. Check dog clutch teeth on
shaft for wear and damage.17. 03 Model Year onwards: Compress high/low
selector fork spring and remove retaining clips
from each end of spring, remove high/low
selector shaft.
High/low selector shaft fitted to pre 03 Model Year
illustrated.
18.Check detent grooves in high/low selector shaft
for wear. Do not remove fork from shaft
unless either component is being renewed.
If fork is removed from shaft, coat the
threads of the set screw with sealant, Part
No. STC 50552 prior to assembling.
19.Check width of high/low selector groove.
lGroove width = 16.0 to 16.1 mm (0.63 to
0.64 in).

TRANSFER BOX - LT230SE
OVERHAUL 41-61
41.Position selected shim in front output housing
and using tool LRT-54-003, fit new differential
front bearing track.
42.Fit bearing spacer to output shaft with chamfer
on spacer towards threaded end.
43. If fitted: Fit dog clutch with flange on clutch
facing towards splined end.
44.Using a copper mallet, drive output shaft into
bearing.
Note: Carry out the following operations for
transfer boxes fitted with differential lock.
45.Compress differential lock selector spring and
fit selector fork.
46.Position selector fork to groove in dog clutch.
47.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. 48.Compress selector spring and fit retaining clips
at each end of spring.
CAUTION: Ensure ends of spring are fully
seated in recess of clips.
49.Apply sealant, Part No. STC 4600 to front
output shaft housing.
50.Position housing ensuring that output shaft and
dog clutch splines - if fitted are correctly
engaged.
51.Clean output shaft housing bolt threads.
52.Apply sealant, Part No. STC 50552 to threads
of bolts.
53.Fit output shaft housing bolts and tighten in a
diagonal sequence to 45 Nm (33 lbf.ft).
54.Apply sealant, Part No. STC 4600 to mating
face of high/low selector housing.
55.Position high/low selector housing to front
output housing ensuring that high/low selector
finger is located in groove in selector shaft.
56. 03 Model Year onwards: Position multiplug
and selector cable brackets to high/low selector
housing
57.Apply sealant, Part No. STC 50552 to threads
of selector housing bolts.
58. Up to 03 Model Year: Fit bolts and tighten to
25 Nm (18 lbf.ft).
59.Fit differential lock detent ball and spring.
60.Apply sealant, Part No. STC 50552 to threads
of differential lock detent plug.
61. 03 Model Year onwards - differential lock
fitted: Fit and tighten detent plug, then loosen
2 complete turns.
62. 03 Model Year onwards - differential lock
fitted: Apply sealant, Part No. STC 50552 to
threads of differential lock detent plug.
63. 03 Model Year onwards - differential lock
fitted: Fit detent ball and spring.

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