differential LAND ROVER DISCOVERY 1999 Repair Manual

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.

TRANSFER BOX - LT230SE
41-60 OVERHAUL
31.Position depth block tool LRT-41-014/2 and
cross bar tool LRT-41-014/1 to front output
housing.
32.Position DTI to tool LRT-41-014/1 cross bar
and zero DTI on depth block.
33.Position DTI to cross bar and record reading
obtained.
34. Using the formula: 3.05 mm (0.120 in)+B-
A=D where: B=Height difference recorded
between depth block and cross bar.
A=Average of readings to differential front
bearing outer track. D=Thickness of shim
required to give differential bearing pre-load of
0.05 mm (0.002 in).
35.From the resultant figure obtained, select
appropriate thickness shim from the range
available.
36.Shims are available from 2.00 to 3.25 mm
(0.08 to 0.13 in) thickness, rising in increments
of 0.05 mm (0.002 in). 37.Heat the front output housing to 100°C (210°F)
and fit new output shaft bearing using tool
LRT-41-011.
38.Allow housing to air cool.
39.Fit new bearing retaining circlip ensuring that
circlip is fully seated.
40.Using tool LRT-41-012, fit new output shaft oil
seal. Check that oil seal is just contacting
circlip.
CAUTION: Oil seal must be fitted dry.

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
41-62 OVERHAUL
64. 03 Model Year onwards - differential lock
fitted: Fit differential lock detent plug and
tighten until head of plug is level with face of
output shaft housing.
65. 03 Model Year onwards - differential lock
fitted: Using a straight edge, check that head
of plug is correctly positioned, screw plug in or
out as necessary.
66. 03 Model Year onwards - differential lock
fitted: Lubricate and fit new 'O' rings to
differential lock selector housing.
67. 03 Model Year onwards - differential lock
fitted: Fit selector housing, ensure selector
finger is located in shaft recess.
68. 03 Model Year onwards: Position cable
bracket to selector housing.
69. Apply sealant, Part No. STC 50552 to threads
of selector housing bolts, fit bolts and tighten to
25 Nm (18 lbf.ft).70. Up to 03 Model Year - differential lock fitted:
Fit nut to differential lock warning lamp switch
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).
71.Apply sealant, Part No. STC 50552 to threads
of differential warning lamp switch.
72.Position switch into front output housing until
nut bottoms out on housing; tighten nut to 11
Nm (8 lbf.ft)
73. 03 Model Year onwards - differential lock
fitted: Fit new aluminium sealing washers to
differential lock warning lamp switches.
CAUTION: Ensure that replacement
washers are the same thickness as the
originals.
74. 03 Model Year onwards - differential lock
fitted: Apply sealant, Part No. STC 50552 to
threads of switches.
75. 03 Model Year onwards - differential lock
fitted: Fit switches and tighten to 25 Nm (18
lbf.ft).
76.Fit output flange, new felt washer, steel washer
and new retaining nut.
M41 7886

TRANSFER BOX - LT230SE
OVERHAUL 41-63
77.Using tool LRT-51-003 to restrain flange,
tighten output flange nut to 162 Nm (119 lbf.ft).
78. If fitted: Operate differential lock selector lever
and check that detent ball can be felt to
positively engage/disengage with grooves in
shaft.
79. Up to 03 Model Year - differential lock
fitted:Screw plug in or out until setting is
correct.
80.Fit high/low selector shaft detent ball and
spring.
81.Apply sealant, Part No. STC 50552 to threads
of high/low selector shaft detent plug.
82. Up to 03 Model Year - differential lock fitted:
Fit and tighten plug, then loosen 2 complete
turns. 83. 03 Model Year onwards - differential lock
fitted: Fit detent plug and tighten until head of
plug is level with face of main casing. Using a
straight edge, check that plug is correctly
positioned; screw plug in or out as necessary.
84. 03 Model Year onwards - differential lock
fitted: Operate high/low selector lever and
check that detent ball can be felt to positively
engage/disengage with grooves in shaft.
85. Up to 03 Model Year - differential lock fitted:
Screw plug in or out until setting is correct.
86.Fit intermediate gear cluster.

+ TRANSFER BOX - LT230SE,
OVERHAUL, Intermediate gear assembly.
M41 7888