differential LAND ROVER DISCOVERY 2002 Service Manual

TRANSFER BOX - LT230SE
OVERHAUL 41-43
4.Remove 3 bolts securing differential lock
selector housing and remove housing.
5.Remove and discard 'O' ring from selector
housing.
6.Remove Allen plug and remove detent spring
and ball.
7.Remove differential lock warning lamp switch
and locknut.
Note: Locknut is only fitted to switches up to 03
MY, a modified switch and sealing washer is
fitted from 03 MY onwards.
8.03 MY onwards: Remove differential lock
warning lamp switch from end of front output
shaft housing, discard sealing washer.
9.Compress differential lock selector fork spring
and remove retaining clips from each end of
spring.
10.Withdraw differential lock selector shaft from
front output housing, recover spring and
remove selector fork.
Note: Carry out the following operations for all
transfer boxes.11.Position tool LRT-51-003 to output shaft drive
flange, remove and discard nut, steel and felt
washers; remove output shaft drive flange.
12.Using a copper mallet, drive output shaft from
housing, recover bearing spacer.
13. If fitted: Noting its fitted position, remove dog
clutch from output shaft.

TRANSFER BOX - LT230SE
41-44 OVERHAUL
14.Remove and discard oil seal from housing.
15.Remove and discard circlip retaining output
shaft bearing.
16.Support housing and drift out output shaft
bearing. 17.Remove and discard differential bearing track
and collect selective shim.
18.Remove Allen plug securing high/low selector
shaft detent spring and ball, remove spring and
ball.
19.Withdraw differential assembly together with
high/low selector shaft and fork.
20.Remove selector fork and shaft from
differential.
Note: Selector fork fitted to 03 MY onwards
illustrated.

TRANSFER BOX - LT230SE
OVERHAUL 41-45
21.Note position of shoulder bolt, remove 6 bolts
and remove rear output shaft housing.
22.Remove rear bearing track from main casing.
23.Secure differential in a soft jawed vice.
24.Release staking from bearing retaining nut.
25.Using tool LRT-41-007 remove and discard
bearing retaining nut. 26.Position tool LRT-99-002 to vice.
27.Position tool LRT-41-001 around rear
differential bearing, position differential to tool
LRT-99-002 and press off bearing.
28.Remove high range gear and bush.

TRANSFER BOX - LT230SE
41-46 OVERHAUL
29.Make suitable alignment marks between high/
low selector sleeve and hub, remove selector
sleeve.
30.Using a suitable press and thrust button LRT-
41-001 remove high/low hub and low range
gear.
31.Position tool LRT-41-002 around front
differential bearing and tool LRT-41-001 t h r u s t
button to differential shaft and press off
bearing. Disassembly
1.Secure rear half of differential carrier in a soft
jawed vice.
2.Make suitable alignment marks between front
and rear halves of differential carrier.
3.Remove 8 bolts securing front half of carrier to
rear and separate both halves of carrier.
4.Suitably identify front sun gear to front half of
carrier, then remove sun gear.
5.Remove and discard thrust washer.
6.Suitably identify each planet gear to its shaft
and fitted position of each cross shaft to rear
half of carrier
7.Remove retaining ring.
8.Remove planet gears and cross shafts, remove
and discard dished thrust washers.
9.Suitably identify rear sun gear to rear half of
carrier, then remove sun gear.
10.Remove and discard thrust washer.

TRANSFER BOX - LT230SE
OVERHAUL 41-47
Inspect
1.Check mating surfaces of cross shaft and
housing bore for wear.
2.Check core plug in housing for signs of leakage
or corrosion ; apply Loctite 326 to replacement
plug.
3.Measuring across widest portion of finger,
check high/low selector finger for wear.
lFinger width = 15.90 to 15.95 mm (0.625 to
0.627 in).
4.Check bearing track recesses in housing for
damage, rectify or replace housing as
necessary.
5. If fitted: Carry out inspection of differential
lock components using following procedures.
6.Check differential lock selector shaft and
housing bore for wear.
7.Measuring across the widest portion, check
differential lock finger for wear.
lFinger width = 15.90 to 15.95 mm (0.625 to
0.627 in).8.Check differential lock selector finger groove in
selector shaft.
lGroove width = 16.0 to 16.1 mm (0.63 to
0.64 in).
9.Check detent grooves in differential lock
selector shaft for wear.
10.Check differential lock detent ball for flat spots
and check detent spring for distortion.

TRANSFER BOX - LT230SE
41-48 OVERHAUL
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 MY onwards: Compress high/low selector
fork spring and remove retaining clips from
each end of spring, remove high/low selector
shaft.
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 Loctite 290
prior to assembling.
Note: High/low selector shaft fitted to pre 03 MY
illustrated.

TRANSFER BOX - LT230SE
OVERHAUL 41-49
19.Check width of high/low selector groove.
lGroove width = 16.0 to 16.1 mm (0.63 to
0.64 in).
20.Check high/low selector fork for cracks and
wear. Check selector fork finger width.
lFinger width = 7.37 to 7.47 mm (0.290 to
0.294 in).
21.03 MY onwards: Check high/low selector fork
clips for wear and damage. Check spring for
distortion, check free length of spring:
lSpring free length = 75 mm (2.95 in)
Note: High/low selector shaft, fork and spring
fitted to 03 MY transfer boxes may be fitted to
pre 03 MY boxes as an assembly.
22.Check differential sun and planet gears for
wear, cracks and chipping of teeth.
23.Check cross shafts and recesses in both halves
of differential carrier for damage and
wear.Ensure planet gears are retained with
their respective shafts.
24.Check retaining ring for distortion.
25.Check differential splines for wear and
damage.26.Check high/low hub for cracks, chipping and
uneven wear. Check width of selector fork
groove.
lGroove width = 7.5 to 7.6 mm (0.295 to 0.30
in).
27.Check splines and teeth on high/low selector
sleeve for uneven wear, cracks, damage and
chipping.
28.Check teeth of high and low range gears for
cracks, chipping and uneven wear.
29.Check high range gear bush for wear and
damage.
Reassembly
1.Lubricate all components with recommended
oil and lightly oil the differential bolt threads.

TRANSFER BOX - LT230SE
41-50 OVERHAUL
2.Secure rear half of differential carrier in a soft
jawed vice.
3.Fit each planet gear to its respective cross
shaft, fit new dished thrust washer to each
gear.
4.Fit cross shafts, planet gears and dished thrust
washers in rear half of carrier.Ensure that
cross shafts are fitted correctly. Do not fit
the sun gear into the rear half carrier at this
stage.
5.Fit retaining ring.
6.Fit a 1.05 mm (0.04 in) thrust washer to sun
gear from front half of carrier. Position gear in
front half of carrier.
7.Ensuring that assembly marks are aligned, fit
both halves of carrier together.
8.Fit the differential carrier bolts and, working in a
diagonal sequence, tighten the bolts to 60 Nm,
(44 lbf.ft).9.Insert the front output shaft into the front half of
the carrier and check that the gears rotate
freely.
10.Fit output flange on to the splines of the output
shaft, but do not fit flange nut at this stage.
11.Fit transmission brake drum to output flange
and secure the drum using 2 nuts.
12.Secure a length of cord around the drum and
attach one end of the cord to a spring balance.
13.Pull on the spring balance and note the load at
which the brake drum starts to turn. Used
gears should rotate smoothly, while new
gears will have a 'notchy' feel as they rotate.
14.Compare the figure obtained with the following.
lUsed gears = 0.45 kg (1.0 lb)
lNew gears = 1.72 kg (3.8 lb)
15.If the load to turn figure is below the specified
limits, proceed as follows.
16.Remove the front output shaft and brake drum.
17.Remove the 8 bolts securing the two halves of
the differential carrier
18.Separate the differential carrier and remove the
sun gear and thrust washer from the front half.
19.Select a thicker thrust washer from the range
available. 5 different thrust washers are
available, rising in increments of 0.10 mm
(0.004 in) from 1.05 mm to 1.45 mm (0.04 to
0.06 in).
20.Repeat steps 7 to 19 as necessary until the
load to turn figure is as specified
21.When specified load to turn is obtained,
proceed as follows.
22.Remove the front output shaft and brake drum.
23.Remove the 8 bolts securing the two halves of
the differential carrier
24.Separate the differential carrier and remove the
sun gear and thrust washer from the front
half.Retain the selected thrust washer with
its sun gear.

TRANSFER BOX - LT230SE
OVERHAUL 41-51
25.Remove retaining ring, then remove the planet
gears and cross shafts.
26.Fit a 1.05 mm (0.04 in) thrust washer to sun
gear from rear half of carrier. Position gear in
rear half of carrier.
27.Fit planet gears, cross shafts and dished thrust
washers to rear half of carrier. Ensure that
cross shafts are fitted correctly. Do not fit
the sun gear into the rear half carrier at this
stage.
28.Fit retaining ring.
29.Ensuring that assembly marks are aligned, fit
both halves of carrier together.
30.Fit the differential carrier bolts and, working in a
diagonal sequence, tighten the bolts to 60 Nm,
(44 lbf.ft).31.Invert the assembly in the vice, insert the rear
output shaft into the rear half of the carrier and
check that the gears rotate freely.
32.Fit output flange on to the splines of the output
shaft, but do not fit flange nut at this stage.
33.Fit transmission brake drum to output flange
and secure the drum using 2 nuts.
34.Carry out the load to turn check, using the same
method as for the front half carrier. Record the
shim thickness when the load to turn is correct.
35.Fit the sun gear and selected thickness shim to
the front half carrier.
36.Ensuring that assembly marks are aligned, fit
both halves of carrier together.
37.Fit the differential carrier bolts and, working in a
diagonal sequence, tighten the bolts to 60 Nm,
(44 lbf.ft).
38.With differential assembled, fit rear output shaft
and brake drum, then check overall load to turn.
This should be approximately the same as the
combined load to turn figure of both front and
rear half carriers.
lUsed gears = 0.90 kg (2.0 lb)
lNew gears = 3.44 kg (7.6 lb)

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.