Discovery 2. Manual — part 619

REAR SUSPENSION

DESCRIPTION AND OPERATION

64-7

Coil springs (vehicles without SLS)
On vehicles without SLS fitted, coil springs are fitted between the rear axle and the chassis in place of the SLS air
springs. Each spring is located at its base by the lower spring seat which is secured to a fabricated platform on the
rear axle with two bolts. The top of each spring is located in the upper spring seat. The upper spring seat comprises
a pressed metal plate with an outer coating of natural rubber bonded to the plate. The upper spring seat is retained
in position by the compression of the spring.

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.

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

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.

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

DESCRIPTION AND OPERATION

64-9

DESCRIPTION AND OPERATION

SLS component layout

RH drive shown, LH drive similar

1 Off-road mode switch
2 SLS warning lamp
3 Instrument pack
4 Off-road mode warning lamp
5 RH Height sensor
6 RH Air spring
7 Air inlet filter
8 LH Air spring
9 LH Height sensor

10 Air supply unit
11 SLABS ECU

REAR SUSPENSION

64-10

DESCRIPTION AND OPERATION

SLS system control diagram