The Jaguar XK8 and XKR Rear Suspension system has generally been very robust in service. The assembly and associated parts are based on the proven Jaguar X300 system which in turn was based on the older Jaguar XJ40 system. However problems are starting to present which the XK8 / XKR owner needs to be aware of. To date, the following are the main issues related to the Jaguar XK8 and XKR Rear Suspension parts assembly:
CATS (Computer Active Technology Suspension) System
Although based on the older X300 rear suspension design, a new modification was the introduction of CATS. This optimises the ride and handling of the car by means of uprated springs to increase the stiffness and electronic adaptive dampers under electronic control. Sensors at the front and rear of the car monitor the road and handling conditions and alter the electronic dampers to soften or stiffen the dampers. On start up the springs default to a stiffer setting and then under way on a smooth road, will soften. The settings will change in micro settings as braking, cornering and road conditions affect the car.
XK8 / XKR Suspension Problems
If you have a car fitted with CATS and the rear suspension is not working effectively then this can be a problem with the electrical connections from the shock absorber going into the wiring loom. Over time, the shock absorbers can actually rotate in service which may cause the electrical connections to be pulled off. This may necessitate the replacement of the shock absorbers part.
As with some other areas of the XK8 / XKR changing the rear shock absorbers parts is not as easy as it may look. Firstly, the rear suspension needs to be unbolted and lowered several inches. A special spring compressor of slim design is required to allow the release of the shock absorber from the spring unit. With the spring suitably compressed, the fulcrum pin can be removed which may well have seized in position. If this is the case, due to the severe lack of space in the area and the bottom of the spring compressor obstructing, this will have to be cut off with a small angle grinder
To complete the removal of the shock absorbers, the rear tie bar needs to be removed together with the A -Frame safety plate. Also remove the nuts holding the top plate of the shock absorber spring pan.