1999 LAND ROVER DISCOVERY ECU

MANUAL GEARBOX - R380
OVERHAUL 37-49
5.Remove 2 bolts securing spool retainer to
gearbox case. Remove retainer, remove and
discard 'O' ring - if fitted.
6.Remove interlock spool from selector shaft.
7.Remove filter from gearbox case.
8.Align selector shaft pin with slot in centre plate
and using wooden blocks and hide mallet,
release centre plate and collect lower detent
ball and spring. 9.Press out reverse idler shaft using a suitable
press.
10.Remove idler gear, needle roller bearing and
spacer.

MANUAL GEARBOX - R380
OVERHAUL 37-51
Lever - gear change
$% 37.16.04
Disassembly
1.Remove gear selector housing.

+ MANUAL GEARBOX - R380,
OVERHAUL, Housing - gear selector
mechanism.
2.Restrain right hand bias spring using a suitable
pair of grips.
3.Remove 2 bolts securing right hand side of bias
spring adjustment plate.
4.Repeat operations for left hand bias spring.
5.Remove bias springs and adjustment plate.6.Remove lower gear lever.
7.Remove and discard Railko bush.
8.Remove and discard oil seal from housing.

MANUAL GEARBOX - R380
37-52 OVERHAUL
Reassembly
1.Clean components.
2.Apply multi-purpose grease to ball and cross
pins.
3.Apply multi-purpose to new Railko bush and fit
to housing ensuring that slots are correctly
aligned.
4.Lubricate a new seal with gearbox oil and fit, lip
side towards housing using a suitable mandrel.
5.Position lower gear lever to selector housing
ensuring cross pins are located in Railko bush.
6.Position bias spring adjustment plate to
selector housing.
7.Clean threads of bias spring adjustment plate
bolts and apply sealant, Part No. STC 50552 to
threads.
8.Fit 2 short bolts to secure front of adjustment
plate and tighten to 25 Nm (18 lbf.ft).
9.Position right hand bias spring to pillar ensuring
longest end of spring is against gear lever.
10.Restrain bias spring using a suitable pair of
grips, ensure shortest end of spring is on
outside edge of bolt hole.
11.Fit longest bolt and washer ensuring end of
bias spring is under washer, tighten bolt to 25
Nm (18 lbf.ft).
12.Repeat above procedures for remaining bias
spring.
13.Fit gear selector housing.

+ MANUAL GEARBOX - R380,
OVERHAUL, Housing - gear selector
mechanism.
14.Adjust gear lever bias springs.

+ MANUAL GEARBOX - R380,
ADJUSTMENTS, Spring - gear lever bias.
Housing - clutch
$% 37.12.07
Disassembly
1.Remove clutch release bearing and operating
lever.
2.Remove 6 bolts and remove clutch housing.
Reassembly
1.Clean clutch housing and gearbox mating face.
2.Position clutch housing and tighten bolts to 75
Nm (55 lbf.ft).
3.Fit clutch operating lever and release bearing.

MANUAL GEARBOX - R380
OVERHAUL 37-53
Cover - front
$% 37.12.33.01
Disassembly
1.Remove retaining peg and remove release
bearing.
2.Remove bolt securing clutch release fork,
remove retaining clip and remove clutch
release fork.
3.Remove 2 bolts securing release bearing
sleeve and remove bearing sleeve. 4.Remove 6 bolts securing clutch housing and
remove clutch housing.
5.Remove and discard 6 bolts securing oil seal
housing.
6.Remove oil seal housing.
7.Using a soft metal drift, carefully remove input
shaft front bearing track from housing.
8.Remove oil seal from housing, discard seal.

MANUAL GEARBOX - R380
37-54 OVERHAUL
Reassembly
1.Using a suitable solvent cleaner, clean seal
housing mating faces.
2.Clean seal recess, bearings and bearing
races.
3.Lubricate new oil seal and fit using a suitable
mandrel into housing.
4.Fit input shaft front bearing track using a press
and suitable mandrel.
5.Apply sealant, Part No. STC 4404 to seal
housing, fit new bolts and tighten by diagonal
selection to 25 Nm (18 lbf.ft).
6.Clean clutch housing mating faces, dowels and
dowel holes.
7.Position clutch housing, fit bolts and tighten to
75 Nm (55 lbf.ft).
8.Clean release bearing sleeve mating faces,
dowel and dowel holes.
9.Position release bearing sleeve, fit bolts and
tighten to 25 Nm (18 lbf.ft).
10.Examine clutch release fork pivot points for
wear and replace as required.
11.Apply a smear of Molybdenum disulphide
grease to pivot points and position release fork.
12.Fit retaining clip ensuring it locates over pivot
point washer, fit bolt to release fork and tighten
to 10 Nm (7 lbf.ft).
13.Clean release bearing and bearing sleeve
mating faces.
14.Apply smear of Molybdenum disulphide grease
to release bearing sleeve.
15.Fit release bearing and secure with retaining
peg.

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
DESCRIPTION AND OPERATION 41-15
Functionality – Vehicles up to 03 model year only
The function of the differential lock used in previous applications is performed on this vehicle by the Electronic Traction
Control System. However, for the purposes of 2 wheel rolling road testing , the differential lock components are
retained. For all driving conditions however, the differential lock must be set in the unlocked position.
Up to 03 model year specification shown
The differential lock must only be engaged for 2 wheel rolling road testing as engagement of the lock disables the
traction control feature and inhibits correct operation of the electronic brake distribution and hill descent features. It
will also be necessary to disconnect the propeller shaft from the transfer box output shaft driving the axle whose
wheels are NOT on the rolling road. The lock may be engaged/disengaged by using a 10 mm open ended spanner
on the flats (arrowed) machined on the differential lock selector shaft.
Vehicles not fitted with a differential lock may be identified by there being no cover or selector shaft (arrowed) on the
front output housing.
WARNING: VEHICLES NOT FITTED WITH A DIFFERENTIAL LOCK MUST NOT BE TESTED ON A ROLLING
ROAD WHERE THE ROLLERS ARE DRIVEN BY THE VEHICLE.
Functionality – Vehicles from 03 model year only
The differential lock must be engaged for 2 wheel rolling road testing. It will also be necessary to disconnect the
propeller shaft from the transfer box output shaft driving the axle whose wheels are NOT on the rolling road. In
addition, the ETC system must be deactivated by either, removing a fuse (10A fuse 28 in the passenger compartment
fusebox, labelled ABS) or disconnecting the ABS modulator pump. This must be done with the ignition switched off.
Note that the SLABS ECU may record a system fault.
The lock can be engaged or disengaged using the selector lever.
WARNING: VEHICLES NOT FITTED WITH A DIFFERENTIAL LOCK MUST NOT BE TESTED ON A ROLLING
ROAD WHERE THE ROLLERS ARE DRIVEN BY THE VEHICLE.

TRANSFER BOX - LT230SE
41-16 DESCRIPTION AND OPERATION
Differential lock warning lamp switch - if fitted - Vehicles up to 03 model year
A differential lock warning lamp switch connected to the SLABS ECU and operated by movement of the selector fork
and shaft is screwed into the top of the output housing. The switch connects to earth when the differential lock is
engaged.
Differential lock warning lamp switches - Vehicles from 03 model year
Vehicles from 03 model year are fitted with two differential lock warning lamp switches.
Both switches are of a new design and are fitted into the top of the front output housing. The switches are connected
to the SLABS ECU and are operated by movement of the selector shaft.
Both switches have an aluminium washer which seals the switch to the casing and also sets the switch position,
removing the requirement for a setting procedure.
Both switches are connected in parallel to earth when the differential lock is engaged. This earth is sensed by the
SLABS ECU which illuminates the differential lock warning lamp in the instrument pack.
Differential lock warning lamp - Vehicles up to 03 model year – if fitted
The differential lock warning lamp is located in the instrument pack and provides a warning to the driver when the
ignition is switched on that the differential lock is engaged. The warning lamp illuminates in a Red colour.
With the lock engaged, the traction control and electronic brake distribution warning lamps will also be illuminated.
Disengagement of the differential lock should be carried out with the ignition switched off. The warning lamps must
be extinguished when the ignition is switched on again.
Differential lock warning lamp – vehicles from 03 model year
The differential lock warning lamp is amber coloured and is located in the instrument pack.
When the lock is engaged, the warning lamp is illuminated and the instrument pack sounder emits three audible
chimes. When the lock is disengaged, the warning lamp is extinguished and the instrument pack sounder emits three
audible chimes.
Rear output housing
The rear output housing carries the output shaft and flange. A cable operated transmission brake is attached to the
housing, the brake drum being attached to the output flange.
The rear output shaft is supported in the housing by a single bearing and is splined into the differential rear sun gear.
Lubrication
Lubrication is by splash, oil filler/level and drain plugs being located in the main casing.
Internal pressures caused by thermal expansion and contraction are avoided by the use of a plastic breather pipe
venting the interior of the box to atmosphere. The pipe is attached to the top of the high/low selector housing by a
banjo bolt and is then routed in a continuously rising path into the engine compartment where the open end is secured
by a clip attached to the engine cylinder block.
Oil temperature warning lamp switch
An oil temperature switch is fitted to V8 engine models up to 03 Model Year. In the event of the transfer box oil
approaching maximum recommended working temperature of 145°C (293°F), the switch will close and a warning
lamp in the instrument pack will be illuminated.