Hello -

This forum has been a wealth of great info for me as I learn about my 2003 XK8 conv, but this is the first time with a questions.

Not to beat a dead horse into mush, but I do have a few questions regarding the suspension and prioritizing what needs to be done first. I've read lots of good suggestions already, but want to confirm a few details:

Car Info
- 2003 XK8 Convertible, 120k miles
- bought from previous owner with no service records. Carfax shows regular services, but no details (and no accidents).
- recently had to replace leaky 5-headed hoses and thermostat housing, etc. (replaced by mechanic)
- Engine runs great, but car shudders (more than just cowl shake) on anything but smoothest roads. Felt mostly thru steering wheel, but in body as well. I've had the wheels balanced (but not road force balanced) which didn't help. Car tracks straight otherwise when driving and during braking.
- Physical inspection shows the upper shock mounts are cracked and ready for replacement.

Questions
1. Is the measurement from wheel center to fender edge the same if I have 19" wheels? Note that I measured 14.25" on both wheels.
2. I know I'm going to need to replace the upper shock mount bushings, based on physical inspection and measurements. Will that possibly also take care of the shuddering issue?
3. What else are the must-haves while replacing those mounts?

Thanks for the help -

 

My wife's 2006 XK8 Victory Edition convertible also has 19-inch wheels. After installing new Welsh Enterprises poly front upper shock mounts along with new Bilstein shocks at just under 99,000 miles in January 2016, the wheel center-to-fender edge measurement increased to the expected 15.5-inch range. At the same time we installed new shock bellows and bump stocks as well as new poly front upper control arm bushings. The vehicle's general handling immediately improved dramatically and has remained that way ever since. Be sure to get your front toe aligned after you do the suspension work....

 

Also check bushings, ball joints etc. I wonder, also, about the state of the sway bar links. I think giandaniel switched his out a year or two ago and experience much better handling and less shuddering, if I recall correctly.

 

Yes to all above. The sway bar bushings are probably worse than the links. Wheel size has nothing to do with ride height, since it's wheel center to fender lip.

 

^^ What he said. Checking my records, I replaced the four rear sway bar link bushings in October 2014 at 84,500 miles. I remember that the metal links were fine, but the rubber bushings were shot....

 

It was actually a less than two months ago for the rears, and last year for the fronts. For the rears I kept the old link but changed out the rubbers for poly's from Energy Suspension. I had to drill the bore of bush to get them to slide in. It was a massive improvement. My entire front suspension is now poly except for the lower shock bushes. I still have to do the rear end's lower shock bushes and upper mounts.

More details here: https://www.jaguarforums.com/forum/x...-after-222599/

 

Thanks everyone for the quick responses. I will update this forum once I complete the work and let you know how comes out, and whether it addresses the suspension issues (I'm confident it will).

 

Had a Chrysler 300 that had tons of shuddering when driving over not perfectly smooth roads.

Sway bar link bushings were the culprit.