Coil springs (vehicles without SLS) (Rear suspension)

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.