Front Suspension

Front Suspension

COMPONENT LOCATION









INTRODUCTION
The front suspension is of a fully independent design. The front suspension components are attached to the front subframe and the vehicle body. The subframe is attached to the vehicle body with four long bolts which pass through bushes located in the subframe.
The front suspension on each side comprises:
- Upper control arm
- Lower lateral control arm
- Lower control arm
- Wheel knuckle and hub assembly
- Stabilizer bar
- Spring and damper assembly.

UPPER CONTROL ARM









The forged aluminum upper control arm is a wishbone design with three mounting points. The two inner mounting points are fitted with bushes. The outer mounting is fitted with a ball joint which locates in a hole in the wheel knuckle and is secured with a locknut.
The inclination of the upper control arm axis provides an anti-dive and anti-squat action during vehicle braking and acceleration and also improves caster trail which in turn improves steering 'feel'.

LOWER LATERAL CONTROL ARM









The forged aluminum lower lateral control arm is fitted with a bush in its inner end which locates between brackets on the subframe. The arm is secured with an eccentric bolt, an eccentric washer and a locknut which allow for the adjustment of the suspension camber geometry.
The outer end of the control arm has a tapered hole which locates on a ball joint fitted to the wheel knuckle. Two cast brackets on the forward face of the control arm allow for the attachment of the lower control arm. A threaded insert is fitted behind the two cast brackets and provides for the attachment of the stabilizer link with a bolt. A bush is fitted to a cross-hole in the control arm which provides the location for the forked attachment of the spring and damper assembly.

LOWER CONTROL ARM









The cast lower control arm is fitted with a hydrabush in its inner end which locates between brackets on the subframe. The arm is secured with an eccentric bolt, an eccentric washer and a locknut which allow for adjustment of the caster and camber geometry.
The outer end of the control arm is fitted with a spherical bearing and locates between the cast brackets on the lower lateral control arm. The lower lateral control arm and lower control arm together form a wishbone design.

WHEEL KNUCKLE









The cast aluminum wheel knuckle is a swan neck design which provides the attachment for the upper control arm and lower lateral control arm. The lower lateral control arm locates on a non serviceable ball joint integral with the wheel knuckle. The lower boss on the knuckle provides for the attachment of the steering gear tie-rod ball joint.
The wheel knuckle also provides the mounting locations for the wheel hub and bearing assembly, the wheel speed sensor, the brake caliper and the brake dust shield, which is retained with 3 rivets.
The wheel hub and bearing assembly is a non-serviceable component that requires replacement as a complete assembly. A magnetic encoder ring for the wheel speed sensor is incorporated into the wheel bearing. The assembly is secured to the knuckle with 2 bolts and 2 Torx bolts.

STABILIZER BAR









The stabilizer bar is attached to the front of the subframe with bushes and mounting brackets. The pressed steel brackets locate over the bushes and are attached to the cross member with bolts screwed into threaded locations in the subframe. The stabilizer bar has crimped, 'anti-shuffle' collars pressed in position on the inside edges of the bushes. The collars prevent sideways movement of the stabilizer bar.
The stabilizer bar is manufactured from 32 mm diameter, manganese steel bar. Each end of the stabilizer bar curves rearwards to attach to a ball joint on a stabilizer link. Each stabilizer link is secured to a bush in the lower lateral arm with a bolt and locknut. The links allow the stabilizer bar to move with the wheel travel providing maximum effectiveness.

SPRING AND DAMPER ASSEMBLY









The spring and damper assemblies are located between the lower lateral arm and the front suspension housing in the inner wing. There are two damper variants:
- A conventional oil damped damper.
- On vehicles with the adaptive dynamics system, a continuously variable adaptive damper. For additional information, refer to Vehicle Dynamic Suspension Description and Operation
Different combinations of springs and dampers are available depending on the vehicle model. The conventional and adaptive damper assemblies are of a similar construction.
The dampers are a monotube design with a spring seat welded onto the damper tube. The lower end of the damper has a forked mounting with a cross hole and captive nut. The fork locates over the lower lateral control arm and is secured with a bolt.
The damper functions by restricting the flow of oil through internal galleries in the damper piston, providing damping of undulations in the road surface.
The damper piston is connected to a damper rod which is sealed at its exit point from the damper body. The threaded outer end of the damper rod locates through a hole in the top mount. A self locking nut secures the top mount to the damper rod. On adaptive dampers an electrical connector is incorporated into the outer end of the damper rod.
The damper rod is fitted with a spring aid which prevents the top mount making contact with the top of the damper body during full suspension compression and also assists with the suspension tune.
The spring rate of the coil springs can differ between models and are color coded for identification. The coil spring locates on a spring packer and a lower spring seat which is integral with the damper body. The spring locates in an upper spring seat which is located on the underside of the top mount.
The top mount has four studs which locate through mating holes in the vehicle inner wing and are secured with self locking nuts.