Suspension: Locations

Front Suspension

COMPONENT LOCATION









OVERVIEW
The front suspension features long travel McPherson struts to optimize on and off road performance.
The suspension components are mounted on a subframe. The subframe is mounted on 4 bushes which have differing compression rates to absorb lateral and longitudinal loading. This provides a rigid platform for front suspension cornering loads, frontal impact absorption and also provides a towing point for off-road recovery.

SPRING AND DAMPER









The spring and damper assembly is a twin tube design with the conventional coil spring located on a welded spring seat on the damper tube. The lower end of the damper body locates in the wheel knuckle which is clamped with a bolt.
The damper functions by restricting the flow of hydraulic fluid through internal galleries within the damper. The damper rod moves axially within the damper, its movement limited by the flow of fluid through the galleries, providing damping of undulations in the terrain. The damper rod is sealed at its exit point from the damper body to maintain the fluid within the unit and to prevent the ingress of dirt and moisture. The seal also incorporates a wiper to keep the rod clean.
The damper rod is located through a central hole in the top mount assembly. The rod is threaded at its outer end. A self-locking nut secures the top mount to the damper rod. A spring aid is fitted to the damper rod to prevent the top mount contacting the top of the damper during full suspension compression and also assists the suspension tune. A boot is fitted between the damper body and the top mount and protects the damper piston rod from damage.
The coil spring fitted differs with vehicle specification. Each spring is colour coded to identify its rating and fitment requirements.
The coil spring is located in a spring seat which is an integral part of the damper body and contains a spring isolator. The design of the spring seat prevents the spring rotating. The spring has a linear rate compression and is inclined to counter cornering forces. The opposite end of the coil spring is also located in a spring isolator which is fitted in the top mount assembly. Both spring isolators are made from rubber and prevent any noise produced during damper and spring compression/extension from being transmitted to the vehicle body.
The top mount is fitted with a top mount bearing which is located between the 2 top mount plates and the damper rod. A self locking nut secures the damper rod to the top mount. The top mount bearing reduces steering resistance by preventing the spring from 'winding' up when the steering in turned. The top mount attaches to a strengthened turret on the chassis with 3 integral studs and self-locking nuts.
Two brackets are welded to the damper body. One bracket provides for the attachment of the stabilizer link. The second bracket provides for the attachment of the brake hose and wheel speed sensor cable. This bracket also positively locates the damper into the wheel knuckle and its location is critical to controlling the vehicle trim height.

LOWER CONTROL ARM









The lower control arm assembly comprises the control arm, a rubber bush, a hydrabush and a ball joint.
The control arm is a pressed steel fabrication. The outer end is fitted with a non-serviceable taper ball joint which mates with the wheel knuckle.
The 2 inner attachments locate in the subframe. The forward attachment is a non-serviceable rubber bush which is pressed into the control arm. This joint locates in a slot in the subframe and is secured with a bolt which is screwed into a threaded boss on the subframe.
The rearward attachment is a hydrabush which is located on a spigot on the control arm. The hydrabush has 2 welded brackets which provides for its attachment to the subframe with 2 bolts and nuts. The hydrabush contains hydraulic fluid and valves which allow controlled displacement of the bush to improve bump and handling characteristics and also reduce road noise transmission. The bush becomes progressively stiffer as the forces on it increase, such as severe braking.

WHEEL KNUCKLE AND HUB ASSEMBLY









The cast steel wheel knuckle provides the attachment for the lower control arm, spring and damper assembly, wheel hub and bearing assembly and the steering tie-rod.
The extended lower boss on the knuckle provides for the attachment of the steering gear tie-rod ball joint. The ball joint is a taper fitting and is secured with a locknut. The tie-rod allows for the adjustment of the front wheel toe angle.
The upper section of the wheel knuckle has a location hole for the damper body. The damper body slides into the hole and locates against an abutment. The rear face of the hole is split and allows the damper body to be secured in the wheel knuckle with a clamp bolt.
Mounting locations are provided for the brake caliper and the brake disc shield. A hole in the top face of the wheel knuckle provides the location for the ABS wheel speed sensor which is secured with a bolt.

STABILIZER BAR









The stabilizer bar is attached to the rear 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 '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 20.5 mm diameter, manganese steel bar. Each end of the stabilizer bar curves forwards to attach to a ball joint on a stabilizer link. Each stabilizer link is secured to a bracket on the damper body with a locknut. The links, which are not handed, allow the stabilizer bar to move with the wheel travel providing maximum effectiveness.
The stabilizer bar bushes are the compression type which grip the bar under compression by the mounting brackets. When fitting replacement bushes, it is important to ensure the bushes are correctly orientated to the bar. Failure to correctly align the bushes will result in excessive pre-load (wind-up) in the bushes when the suspension is at its nominal ride height.