Front suspension (Accelerometers): Description and operation

The right hand end of the torsion bar has a machined spigot which provides for the attachment of the forged steel short and long arms. The spigot for the short arm is splined and mates with splines in the short arm. The short arm is located in a specific position on the splines and clamped to the spigot with a Torx bolt and locknut. The short arm is not a serviceable item other than the actuator attachment bush. The smaller spigot diameter locates the long arm. The long arm is fitted with a slipper bush which is located on the spigot and secured with a large washer and a special bolt. The slipper bush comprises two inner and two outer bushes which are installed from each side of the long arm. The outer bushes have three lugs which locate in the long arm to prevent the bush from rotating. The long arm also provides the attachment point for the actuator piston rod and the anti-roll bar link.

The actuator has a forked end which locates on the bush in the short arm and is secured with a bolt and nut. The piston rod of the actuator locates through a hole in a cast boss on the long arm which is fitted with a special bush. A shoulder on the piston rod seats in a hole in the bush and a locknut on the end of the piston rod secures the rod to the long arm and bush.

The front torsion bar is attached to the front chassis cross member. Two rubber bushes are fitted to the torsion bar and are located in clamp plates. The clamp plates are located in slots in the cross member and secured with bolts.

The rear torsion bar is attached to the tubular cross member at the rear section of the chassis. Two rubber bushes are fitted to the torsion bar and are located in clamp plates. The clamp plates are located in fabricated brackets attached to the tubular cross-member and secured with bolts.

Two anti-roll bar links are mounted on brackets on the front and rear axles. Each anti-roll bar link is fitted with a spherical bearing at each end. One bearing is attached to the link at a 90° angle. The threaded shank of the bearing is located through a hole in a bracket on the axle and secured with a locknut; a washer is installed on the threaded shank between the bearing and the bracket. The second spherical bearing is attached in-line with the link and locates in the torsion bar on the left hand side and the long arm on the right hand side. The front anti-roll bar links are longer than the rear links and are not interchangeable.

Accelerometers

Two accelerometers are used for the ACE system. The upper accelerometer is mounted on a bracket, behind the headlining adjacent to the rear view mirror and the sunroof ECU. The lower accelerometer is located on a bracket on the inner sill panel under the RH front floor.

The lower accelerometer is the primary sensor used to measure lateral acceleration of the vehicle for roll control. The upper accelerometer is used by the ECU for roll correction and fault detection in conjunction with the lower accelerometer.

Each accelerometer is a solid state capacitive acceleration sensor and operates on a 5 V supply from the ECU. The upper and lower sensors can measure acceleration in the range of ± 1.10 g and return an output to the ECU of between 0.5 and 4.5 V.

Failures of an accelerometer are recorded by the ECU and can be retrieved using TestBook. A special tool is required to remove and replace a sensor in the bracket.