1999 LAND ROVER DISCOVERY ABS

FRONT SUSPENSION
REPAIRS 60-33
Wheel hub
$% 60.25.01
Remove
1.Release ABS sensor harness grommet from
inner wing valance and disconnect multiplug.
2.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
3.Remove road wheel.
4.Pull ABS sensor harness through aperture into
wheel arch.5.Release harness from brackets on inner wing
valance, suspension turret and front hub.
6.Release stake from drive shaft nut.
7.With assistance, remove drive shaft nut.
Discard the nut.
8.Remove front brake disc.

+ BRAKES, REPAIRS, Brake disc -
front.
9.Remove 4 bolts securing wheel hub to steering
knuckle.
10.Release wheel hub from steering knuckle, then
remove wheel hub and drive shaft assembly
from axle.
CAUTION: Do NOT remove the ABS sensor
from the hub. The hub and the sensor are
supplied as an assembly.

FRONT SUSPENSION
60-34 REPAIRS
11.Position the wheel hub and drive shaft on a
press, place supports beneath the wheel studs
and press the drive shaft from the wheel hub.
12.Remove drive shaft oil seal from axle casing. Refit
1.Clean drive shaft oil seal recess, drive shaft
splines, oil seal running surface, wheel hub
and steering knuckle mating faces, ABS
sensor and sensor recess.
2.Lubricate lip of new drive shaft oil seal and
running surface on drive shaft with clean
differential oil.

+ CAPACITIES, FLUIDS,
LUBRICANTS AND SEALANTS,
Lubrication.
3.Use tool LRT-51-012 to fit new drive shaft oil
seal to axle casing.
4.Fit drive shaft to axle casing.
5.Apply anti-seize compound to wheel hub and
steering knuckle mating face.
M51 0057

FRONT SUSPENSION
REPAIRS 60-35
6.Apply a 3 mm (0.125 in) wide bead of sealant,
Part No. STC 50554 around drive shaft
circumference, as illustrated.
7.Ensure ABS harness is located in cut out in
steering knuckle.
8.Fit wheel hub to drive shaft and align steering
knuckle. The sealant will smear along the
length of the splines as the wheel hub is fitted
to the drive shaft.
9.Fit wheel hub bolts and tighten to 100 Nm (74
lbf.ft).
10.Fit new drive shaft nut and lightly tighten.
11.Fit front brake disc.

+ BRAKES, REPAIRS, Brake disc -
front.
12.With assistance, final tighten drive shaft nut to
490 Nm (360 lbf.ft). Stake drive shaft nut. The
drive shaft nut must be tightened before
sealant has cured.
13.Secure ABS sensor harness to brackets and
secure grommet to inner wing.
14.Fit road wheel and tighten nuts to 140 Nm (103
lbf.ft).
15.Remove stand(s) and lower vehicle.
16.Connect ABS sensor multiplug.
Damper - front
$% 60.30.02
Remove
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Remove road wheel.
3. RH damper: Release coolant reservoir and
position aside.
4.Loosen through bolt securing damper to turret.
WARNING: Make sure the axle cannot move
when the damper is disconnected. The
damper limits the downward movement of
the axle. If the axle is not restrained,
disconnecting the damper will allow
unrestricted movement which may cause
personal injury or damage to equipment.
M51 0058

FRONT SUSPENSION
REPAIRS 60-39
ECU - ACE
$% 60.60.01
Remove
1.Remove BCU.

+ BODY CONTROL UNIT, REPAIRS,
Body control unit (BCU).
2.Remove 5 multiplugs from SLABS ECU.
3.Remove multiplug from ACE ECU.
4.Remove lower nut and loosen upper nut
securing SLABS and ACE ECU bracket to
body.
5.Remove ECU's and bracket assembly. 6.Remove 3 nuts securing ACE ECU and remove
ACE ECU.
Refit
1.Fit ACE ECU to bracket and secure with nuts.
2.Fit ECU's and bracket assembly to body and
secure with nuts.
3.Connect multiplugs to ACE ECU and SLABS
ECU.
4.Fit BCU.

+ BODY CONTROL UNIT, REPAIRS,
Body control unit (BCU).
5.If a replacement ACE ECU has been fitted, use
TestBook to calibrate ACE system.

REAR SUSPENSION
DESCRIPTION AND OPERATION 64-9
DESCRIPTION AND OPERAT ION
SLS component layout
RH drive shown, LH drive similar
1Off-road mode switch
2SLS warning lamp
3Instrument pack
4Off-road mode warning lamp
5RH Height sensor
6RH Air spring7Air inlet filter
8LH Air spring
9LH Height sensor
10Air supply unit
11SLABS ECU

REAR SUSPENSION
DESCRIPTION AND OPERATION 64-11
1Battery supply (via SLABS relay)
2Ignition supply
3RH height sensor
4LH height sensor
5Off-road mode warning lamp
6Audible warning speaker
7Instrument pack
8SLS warning lamp
9Fusible link 9
10SLS relay
11Air supply unit
12RH air valve
13LH air valve
14Exhaust valve
15Diagnostic socket
16Off-road mode switch
17SLS remote handset
18Body Control Unit (BCU)
19Door switches
20SLABS ECU
21Engine Control Module (ECM)

REAR SUSPENSION
64-12 DESCRIPTION AND OPERATION
Description - SLS
General
The Self Levelling Suspension (SLS) system is an optional fitment and comprises an Electronic Control Unit (ECU),
air supply unit, two air springs and two height sensors. The SLS system only operates on the rear suspension and is
designed to keep the vehicle level to compensate for uneven loads or when towing. The system controls the gap
between the chassis and the rear axle to a tolerance of ± 0.5 mm (0.02 in). The ride height of the rear of the vehicle
can be controlled in three modes of operation; normal ride height, Off-Road Mode (ORM) and extended mode. A
transportation mode, initiated using TestBook, is also available for moving the vehicle on a trailer.
The system is controlled electronically by an ECU which is shared with the ABS system and known as the Self
Levelling and Anti-Lock Braking System (SLABS) ECU. The system operates by using an air supply unit to inflate or
deflate the air springs to maintain a constant ride height.
An accessory remote handset is available to remotely operate the SLS system to allow easier connection and
disconnection of trailers.
Two SLS system warning lamps are located in the instrument pack. The warning lamp in the bottom left corner of the
instrument pack is the SLS warning lamp. If a fault is detected in the system, the warning lamp will illuminate
continuously in an amber colour. The warning lamp also flashes in an amber colour when the remote handset is being
used. The second warning lamp, located in the top right of the instrument pack is the ORM warning lamp. When ORM
is selected the warning lamp is continuously illuminated in an amber colour. When the SLS is between standard ride
height and ORM or in extended mode, the warning lamp will flash. Standard ride height, measured between the tip of
the axle bump stop rubber and the axle, is 61.5 mm (2.42 in). ORM ride height, measured between the tip of axle
bump stop and the axle, is 100 mm (3.93 in).
A switch is located in the group of six switches on the fascia and is used to select the ORM. The switch is non-latching
and must be depressed for a minimum of 0.5 seconds to signal the ECU that ORM has been requested.

REAR SUSPENSION
DESCRIPTION AND OPERATION 64-13
Air supply unit
1Compressor electrical connector
2Electric motor
3Air intake hose
4Compressor
5Air dryer
6Pressure limiting valve
7Exhaust hose
8Exhaust valve electrical connector
(black harness connector)
9Exhaust valve10LH air valve electrical connector
(blue harness connector)
11LH air valve
12LH air spring supply pipe
13Air supply/exhaust pipe
14RH air spring supply pipe
15RH air valve
16RH air valve electrical connector
(natural harness connector)
17Housing
The air supply unit is located in a central position on the outside of the left hand chassis longitudinal. The unit is
contained in a plastic housing attached to the chassis. The housing has a removable lid which is secured with Dzus
fasteners for access to the unit.
The air supply unit comprises a 12 V electric motor, a compressor and air dryer unit, a pressure limiting valve, an
exhaust valve and two air supply control valves. The exhaust and control valves are solenoid operated responding to
signals from the SLABS ECU. The electric motor, compressor, air dryer and pressure limiting and exhaust valve are
mounted on flexible rubber mountings to reduce operating noise.
The electric motor drives a crank with an eccentric pin to which a connecting rod is attached. The connecting rod has
a piston which fits in the bore of the compressor. Operation of the motor rotates the crank, moving the piston in the
bore of the compressor.