1999 LAND ROVER DISCOVERY Workshop Manual

TRANSFER BOX - LT230SE
41-52 OVERHAUL
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 sealant, Part No. STC 3811
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).Note: Differential lock selector shaft fitted to 03
Model Year onwards illustrated.
8.Check differential lock selector finger groove in
selector shaft.
lGroove width = 16.0 to 16.1 mm (0.63 to
0.64 in).
Differential lock selector shaft fitted to 03 Model Year
onwards illustrated.
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
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
41-54 OVERHAUL
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 Model Year 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 Model Year transfer boxes may be
fitted to pre 03 Model Year 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.

TRANSFER BOX - LT230SE
OVERHAUL 41-55
Reassembly
1.Lubricate all components with recommended
oil and lightly oil the differential bolt threads.
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
41-56 OVERHAUL
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
OVERHAUL 41-57
Refit
1.Clean differential components. Remove all
traces of sealant from housings and bolts,
differential lock warning lamp switches and
detent plugs.
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.

TRANSFER BOX - LT230SE
41-58 OVERHAUL
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.
CAUTION: Ensure that threads of
replacement nut are 'Patched'.
11.Using feeler gauges, determine clearance
between low range gear and high/low hub:
lClearance = 0.05 to 0.15 mm (0.002 to
0.006 in).
12.If clearance is not as specified, fit a new low
range gear and high/low hub and re-check. 13.Using feeler gauges, determine clearance
between high range gear and high/low hub:
lClearance = 0.05 to 0.15 mm (0.002 to
0.006 in).
14.If clearance is not as specified, fit new high
range gear and high/low hub and re-check.
15.Using a suitable drift, stake collar of nut into
differential shaft recess.
16.Using LRT-51-009, fit new rear bearing track
into main casing.
17.Using a straight edge and feeler gauges, check
that bearing track is recessed 1 mm (0.04 in)
below outer face of main casing.
18.Apply sealant, Part No. STC 4600 to rear
output shaft housing face.
19.Position housing to main casing.

TRANSFER BOX - LT230SE
OVERHAUL 41-59
20.Apply sealant, Part No. STC 50552 to bolt
threads fit housing to main case, fit bolts and
tighten by diagonal selection to 45 Nm (33
lbf.ft).
21. 03 Model Year onwards: Fit high/low selector
fork and spring to high/low selector shaft, fit
retaining clips.
CAUTION: Ensure ends of spring are fully
seated in recess in clips.
22.Position high/low selector shaft and fork to
differential ensuring that fingers of selector fork
are located in selector sleeve.
23.Position differential assembly into main casing
ensuring that splines of rear output shaft are
engaged in differential.
24.Position new differential front bearing track
ensuring that track is seated squarely.
25.Position tool LRT-41-014/3 onto main casing.
26.Screw tool LRT-41-014/4 into tapped hole in
main casing and attach suitable DTI to pillar.
27.Position stylus of gauge to setting block LRT-
41-014/3 and zero gauge. 28.Position stylus onto front bearing outer track
and record reading.
29.Taking care not to disturb bearing, position
stylus on opposite side of bearing track and
record reading.
30.Obtain average of the 2 readings and record
figure.