In this brief article we are going to discuss the Rear Suspension issues that occur in the Jaguar XK8, what the causes are, and Troubleshooting Tips.
Top 3 Rear Suspension problems in Jaguar XK8
- Rattling from the rear
- Vague Steering; Suspension Noise
- Bumping Noise from the Rear
What Rear Suspension does the Jaguar XK8 have?
The Jaguar XK8 was the coupé model and also the initial model from the XK range of grand tourers launched in 1996. The Jaguar XK8 belongs to the project code X100.
The Rear Suspension on the XK8 is a Double Wishbone with Coil Springs and Anti-Roll Bar. This Rear suspension design uses the second generation of Jaguar’s Independent Rear Suspension (IRS) unit, taken from the Jaguar XJ (XJ40) Project.
The CATS (Computer Active Technology Suspension) adaptive suspension, was initially introduced as an option on the XK8 coupé later on was offered for the Convertible model as well.
The CATS optimises the ride and handling of the car by means of electronic adaptive dampers under electronic control. Accelerometers at the front and rear of the car monitor vibration and speed and pass the information to the CATS, which in turn alters the electro-magnetic damper valves to change to either a softer or stiffer damper setting. On starting the car, the Dampers default to a stiffer setting and then after driving on a smooth road, will soften.
Rear Rattling Noise in XK8
The Major Symptoms of Rear Rattling Noise Issue are:
- A Low level rattling similar to a loose exhaust during normal Driving
- In some cases, there would also be an accompanying scraping/louder bump
Root Causes for Rear Rattling in XK8
The probable sources of this kind of noise could be
- The Rear A-frame (Subframe) bushes
Troubleshooting Rear Rattling in XK8
- The Rear A-frame (Subframe) bushes. These isolate the Body from the impacts of the suspension. Once these bushes wear out, the Body experiences much more of the Road.
- Also having a Subframe that is not securely in place because of a damaged bushing, could be a safety issue because the subframe could move with respect to the body.
- Subframe mounting failure is therefore a major source of ‘Rattling’ Noise
Vague Steering with Rear Rattling Issue
The Major Symptoms of Vague Steering issue are:
- Steering seems vague and difficult to control
- Vehicle seems to wander a bit
- Mild knocking and Rattling noises coming from the Rear
Root Cause for Vague Steering with Rear Rattling
- Most Probable Cause for Vague Steering is Suspension linkages
- If noise comes from the rear, and the steering feels vague, it is definitely related to the Rear suspension Toe setting. The Rear Tie Rod that controls toe setting, must be having an issue
Troubleshooting Vague Steering Problem
- Check the rear Tie-rod for play or looseness. To know if there is play, just Push the tie-rod back and forth with your hand along its length.
- There should not be movement in a good part. Once you notice play, then it’s time to replace the Tie-rod
Bumping Noise from the Rear
The Major Symptoms of Rear Bumping Noise are:
- Bumping noise while going over moderate Roads with a bit of movement in the suspension
- Rear end also feels like it has the tendency to ‘Jump’ a bit more
Root Cause for Bumping Noise from the Rear
- The Knocking noise and Bumpiness mostly point to a worn-out Shock Absorber
- Inspect the Rear Shock absorber and its mountings
Troubleshooting Rear Bumpy Noise
- Corroded Shock mounts are also a potential for rattling
- Damaged Shock Mount Bottom Bushes add to the knocks. Unfortunately, the Bottom mount is not openly visible. It would have to be first removed from its bottom mount, after compressing the spring
- In some cases the bottom mount would have fully corroded and the mounting bolt (which is almost 7 inches long) would have seized itself up within the spring seat.
- Using a Rust penetrator may not always work in severe cases of seizure. In that case, it would be wise to cut out the mounting bolt as well as the shock bottom eye, to save a lot of time
In this brief article we have discussed the Rear Suspension issues that occur in the Jaguar XK8, what the causes are, and Troubleshooting Tips.