oil LAND ROVER DISCOVERY 1999 Workshop Manual

REAR SUSPENSION
DESCRIPTION AND OPERATION 64-7
Coil Spring Specifications – Models up to 03 Model Year
The rear coil springs are of the variable rate type and are manufactured from silicon manganese 16.5 mm (0.65 in.)
diameter bar. Each spring has 9 coils and a free length of 385 mm (15.1 in.). The variable rate of the spring is achieved
by the active coils at one end being closer together. The rear coil spring is identified by a purple stripe painted on a
number of coils.
Coil Spring Specifications – Models From 03 Model Year
The introduction of the 03MY vehicle introduced a range of additional rear coil spring fitments. These were introduced
as a package to optimise vehicle trim heights.
The coil springs are manufactured from silicon manganese 16.35 mm (0.64 in.) diameter bar for springs on five seater
models and 16.57 mm (0.65 in.) diameter bar on seven seater models. The following spring data table shows the
colour codes, number of coils and spring free length.
Spring Data
The following table shows spring fitment applicability.
Spring Fitment Applicability
Watts linkage
A Watts linkage is used to ensure that the rear axle remains centrally located. The Watts linkage comprises two
transverse links and a pivot housing. The transverse links and pivot housing allow the rear axle to move vertically
without any transverse movement.
The transverse links are made from fabricated and welded steel. Each transverse link has a bush press fitted into a
housing at one end. The opposite end has a forked bracket with two cross holes.
The pivot housing is made from cast iron. Three bushes are press fitted in the housing, one in the centre and one at
each end.
The pivot housing is located in a fabricated bracket centrally located on the rear of the axle. The central bush of the
pivot housing is secured in the bracket with a bolt and locknut. Fabricated brackets on each chassis longitudinal
provide for the attachment of each transverse link. Each link is secured through its bush with a bolt and locknut. The
forked end of each link locates over the bushes at each end of the pivot housing and is secured with a bolt and locknut.
The attachment bolts for each link are coated with a clear, dry wax which reduces friction on the bolt and allows the
correct torque to be applied to the clamping of the bushes. The bolts can be re-used, but if bolt replacement is
necessary the correct bolt with the wax coating must be used.
Colour Code Total No. of Coils Free Length Model
Brown/Orange 8.73 384.7 mm (15.14 in) 5 Seat
Grey/Orange 8.73 392 mm (15.43 in) 5 Seat
Yellow/Grey 8.73 376.6 mm (14.82 in) 5 Seat
Pink/Grey 8.73 400.3 mm (15.75 in) 5 Seat
Blue/Grey 9.10 387.8 mm (15.26 in) 7 Seat
Green/Grey 9.10 395.2 mm (15.55 in) 7 Seat
White/Grey 9.10 380.6 mm (14.98 in) 7 Seat
Left Hand Drive Right Hand Drive
Both Sides RH Side LH Side
Brown/Orange Grey/Orange Yellow/Grey
Grey Orange Pink/Grey Brown/Orange
Blue/Grey Green/Grey White/Grey

REAR SUSPENSION
64-8 DESCRIPTION AND OPERATION
Anti-roll bar
The anti-roll bars fitted differ between ACE and non-ACE vehicles. On non-ACE vehicles a conventional 'passive' anti-
roll bar is used. On ACE vehicles an 'active' torsion bar is used. Both types are attached to the tubular cross-member
at the rear of the chassis with mounting rubbers and clamp plates. The clamp plates locate in fabricated brackets
attached to the tubular cross-member and secured with bolts.
Each end of the anti-roll bar is attached to an anti-roll bar link. Each link has a spherical bearing attached at each end.
One end is attached to a bracket on the axle and secured with a locknut. The opposite end attaches through a hole
in the anti-roll bar and is also secured with a locknut. On 'active' torsion bars, the RH anti-roll bar link is attached to a
long arm which in turn is attached to the anti-roll bar.
Passive anti-roll bar
The passive anti-roll bar is a conventional anti-roll bar which opposes axle movement, reducing the effects of lateral
forces on the vehicle body.
With the conventional passive anti-roll bar, axle movement is opposed by the anti-roll bar through links attached to
the axle casing and each end of the anti-roll bar.
On vehicles with coil springs (no SLS fitted) the anti-roll bar is manufactured from 19 mm (0.74 in.) diameter spring
steel bar.
On vehicles with air springs (SLS fitted) the anti-roll bar is manufactured from 29 mm (1.14 in.) diameter spring steel
bar.
Active torsion bar

+ FRONT SUSPENSION, DESCRIPTION AND OPERATION, Description - ACE.The 'active' torsion bar is
used in conjunction with the ACE system to control body roll and directional stability giving a reduction of the effects
of lateral forces on the vehicle body over a conventional 'passive' anti-roll bar.
The torsion bar opposes axle movement by the application of a hydraulic force to oppose the lateral forces through
links attached to the axle casing and each end of the bar. The torsion bar is made from 35 mm (1.4 in.) diameter spring
steel. One end is fitted with an arm which is operated by a hydraulic actuator to oppose corning forces.

REAR SUSPENSION
64-16 DESCRIPTION AND OPERATION
Air springs
1Top plate
2Voss connector3Air bag
4Piston
On vehicles without SLS, coil springs are used. On vehicles with SLS two air springs are fitted between the chassis
and the rear axle to replace the coil springs. Each air spring is located at its base on a fabricated platform on the rear
axle. The top of the spring locates in a fabricated bracket attached to the outside of each chassis longitudinal.
The plastic base piston is recessed with a boss with two lugs moulded in the centre for attachment to the axle. The
piston is secured by locating the lugs in a slotted hole in the axle platform and rotating the spring through 90°, locating
the lugs in the slot. The plastic top plate has two grooved pins which locate through holes in the chassis bracket. Two
spring clips locate on the grooved pins and retain the top of the spring in position.
Each air spring comprises a top plate, an air bag and a base piston. The air bag is attached to the top plate and the
piston with crimped rings.
The air bag is made from a fibre reinforced flexible rubber material which allows the spring to expand with air pressure
and deform under load. The top plate comprises the two bonded grooved pins and a female Voss connector in the
centre. The Voss connector allows for the attachment of the air supply pipe from the air supply unit. The piston is also
made from plastic and is shaped to optimise the springs characteristics.

REAR SUSPENSION
64-28 REPAIRS
10.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.
Refit
1.Clean drive shaft splines, wheel hub and axle
mating faces, ABS sensor and sensor recess.
2.Fit drive shaft to axle casing.
3.Lubricate new bearing hub 'O' ring with clean
differential oil.

+ CAPACITIES, FLUIDS,
LUBRICANTS AND SEALANTS,
Lubrication.
4.Fit 'O' ring to wheel hub.
5.Apply a 3 mm (0.125 in) wide bead of sealant,
Part No. STC 50554 around drive shaft
circumference as illustrated.
6.Fit wheel hub to drive shaft and align to axle.
The sealant will smear along the length of the
splines as the wheel hub is fitted to the drive
shaft.
7.Fit bolts securing wheel hub to axle and tighten
to 100 Nm (74 lbf.ft).
8.Fit new drive shaft nut and lightly tighten.
9.Fit rear brake disc.

+ BRAKES, REPAIRS, Brake disc -
rear.
10.With an assistant depressing the brake pedal,
tighten drive shaft nut to 490 Nm (360 lbf.ft).
Stake drive shaft nut. The drive shaft nut
must be tightened before the sealant has
cured.
11.Connect ABS sensor multiplug and secure
harness to harness bracket and brake hose.
12.Fit road wheel and tighten nuts to 140 Nm (103
lbf.ft).
13.Remove stand(s) and lower vehicle.
M51 0057
M51 0058

REAR SUSPENSION
REPAIRS 64-29
Road spring - rear
$% 64.20.01
Remove
1.Raise rear of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Support vehicle under chassis.
3.Remove road wheel.
4.Support weight of axle on a jack.
5.Remove bolt securing damper to axle.
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.
6.Remove clip securing brake pipe to bracket.
7.Release ABS sensor lead from bracket.
8.Lower axle on jack and remove spring.Refit
1.Ensure spring seats are clean.
2.Fit spring with close coil uppermost.
3.Ensure spring is correctly located on spring
seats and raise axle. Fit and tighten bolt
securing damper to axle to 124 Nm (91 lbf.ft).
4.Fit clip to secure brake pipe to bracket.
5.Fit ABS sensor lead to bracket.
6.Fit road wheel and tighten nuts to 140 Nm (103
lbf.ft).
7.Remove stand(s) and lower vehicle.

BRAKES
70-10 DESCRIPTION AND OPERATION
Vacuum pump (diesel models only)
1Alternator
2Vacuum pump
3Brake servo assembly vacuum connection4Oil feed pipe
5Oil drain pipe
As the diesel engine air inlet system does not produce sufficient depression to operate the brake servo assembly, an
engine driven vacuum pump is installed.
The vacuum pump is integrated with the engine alternator and driven by the auxiliary drive belt. The pump is a rotary
vane type, lubricated and cooled by engine oil supplied through a pipe connected to the engine block and returned
through a pipe connected to the engine oil sump. Air extracted from the brake servo assembly is vented into the oil
sump with returning lubricating oil.

BRAKES
70-24 DESCRIPTION AND OPERATION
Default strategies
Electrical data
Nominal resistance values for applicable brake control components are as detailed below:
Fault Default strategy
Brake lamps relay ABS: Enabled.
ETC: Enabled.
EBD: Enabled.
HDC: Enabled.
Throttle position signal failure ABS: Enabled.
ETC: Disabled.
EBD: Enabled.
HDC: Immediately disabled if not in active braking mode; faded out then disabled if in active
braking mode.
No reference earth ABS: Disabled.
ETC: Disabled.
EBD: Partly disabled.
HDC: Disabled.
Return pump or relay fault ABS: Disabled.
ETC: Disabled.
EBD: Partly disabled.
HDC: Disabled.
Shuttle valve switch failure ABS: Deceleration threshold increased; return pump activated if sum of output valve
actuation on one axle exceeds 140 milliseconds.
ETC: Disabled.
EBD: Inlet valves of rear axle close at vehicle deceleration rates of 0.3 g and above.
HDC: Disabled.
SLABS ECU internal failure ABS: Disabled.
ETC: Disabled.
EBD: Disabled.
HDC: Disabled.
Supply voltage out of limits ABS: Disabled.
ETC: Disabled.
EBD: Disabled.
HDC: Disabled.
Component Resistance, ohms
Brake lamp relay coil117 - 143
Return pump relay coil82.8 - 101.2
ABS sensor950 - 1100
Shuttle valve switches, both open (brakes off) 2977 - 3067
Shuttle valve switches, both closed (brakes on) 1007 - 1037
Shuttle valve switches, one open, one closed 1992 - 2052
Inlet solenoid valve5.9 - 7.3
Outlet solenoid valve3.0 - 3.6

BRAKES
REPAIRS 70-43
Vacuum pump - servo
$% 70.50.19
Remove
1.Remove auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
2.Release cover and remove nut securing lead
to alternator.
3.Disconnect alternator multiplug.
4.Remove bolt (LH thread) and remove auxiliary
drive belt tensioner. 5.Remove bolt securing support stay to
alternator.
6.Release clip and disconnect oil drain hose from
vacuum pump.
7.Disconnect vacuum pump oil supply pipe from
cylinder head and discard 'O' ring.
8.Remove bolt securing alternator and release
from mounting bracket.
9.Disconnect vacuum hose from vacuum pump.
10.Remove alternator. Take care not to damage
radiator cooling fins.
11.Remove 4 bolts, and remove vacuum pump
from alternator.
CAUTION: Always fit plugs to open
connections to prevent contamination.

BRAKES
70-44 REPAIRS
Refit
1.Clean mating faces of alternator and vacuum
pump.
2.Fit vacuum pump to alternator and tighten
bolts to 8 Nm (6 lbf.ft).
3.Position alternator to engine and connect
multiplug.
4.Connect vacuum hose and oil drain hose to
vacuum pump and secure clips.
5.With assistance align alternator to mounting
bracket and fit but do not tighten bolt.
6.Fit bolt securing support stay to alternator and
tighten to 25 Nm (18 lbf.ft) .
7.Tighten bolt securing alternator to mounting
bracket to 45 Nm (33 lbf.ft).
8.Using new 'O' ring, connect oil supply pipe to
cylinder head and tighten to 10 Nm (7 lbf.ft).
9.Connect lead to alternator and tighten nut to 6
Nm (4.4 lbf.ft).
10.Fit auxiliary drive belt tensioner and tighten bolt
to 50 Nm (37 lbf.ft).
11.Fit auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.

SEATS
76-5-4 DESCRIPTION AND OPERATION
Description - electric seats
General
All markets use the same electric seat system. Electically operated lumbar support is optional. The system consists
of an electrical sub-system and a mechanical sub-system.
The electrical sub-system consists of the following components:
lBCU.
lSeat power relays.
lSeat switch packs.
lSeat fore/ aft motors.
lSeat cushion front up/ down motors.
lSeat cushion rear up/ down motors.
lSeat squab motor.
lLumbar pump.
lLumbar deflate solenoid.
The mechanical sub-system consist of the following components:
lGear wheels.
lRack and pinion assemblies.
Seat power relay
Located beneath the seat, the seat power relay supplies battery voltage to the satellite fuse box. Operation of the
relays is controlled by the BCU.
Voltage to the seat power relays is from fuse 5 in the engine compartment fuse box. The BCU controls the earth for
the relay coils. Operating the seat power relays provides voltage to the satellite fuse box under each seat.
Satellite fuse box
Located beneath the seat, the satellite fuse box provides circuit protection for the wiring to the seat switches and
motors. It also protects the lumbar inflate and deflate circuits.
The seat power relay provides voltage directly to the 40A fuse in the satellite fuse box. Voltage from this fuse feeds
the seat switch pack. The 3A fuses in the satellite fuse box protect the wiring to the lumbar pump and lumbar deflate
solenoid. Voltage to the 3A fuses comes from the seat switch pack.