Hey Gordo/Eshezo--thanks for the photos and schematics.

The mechanic I saw last year replaced lower bushings and I had gone back a few times for him to check for more but he never found anything obvious. Another mechanic that I drove around with went right to the brace from the strut tower to the bulkhead as a possible culprit. The interesting thing is that when I tightened the T50 fastener at the bulkhead end of that brace, the clunk seems to have diminished somewhat but is still there. I will probably bring the car in again when I get the chance and specifically direct the guy to look at upper bushings.

Doug

 

Doug,
It could be the upper shock mounts, for sure. But the upper control arm bushings seem to fail sooner. I had mine done by my local mechanic who I trust with the Jag. When he diagnosed it, he told me he checked with Jaguar and they wanted somethings like $700 for the parts, telling him the bushes could not be removed. I told him about what I'd learned on the forum and he suggested I buy the parts myself and he would install them. Sure enough I found them at PartsGeek (I think) for about $100 or so. I also ordered new ball joints, too, since it would be simple to do them at the same time. All went well. My guy had a machine shop press out the old bearings and press in the new. Check out Reverend Sam's video on the shock mounts, which includes removing the control arms at:
He has posted dozens of great XK8 DIY videos there.

 

Well now I have 2 candidates to point my mechanic to--upper bushings and upper shock mount. What I really want to know is if there is a way for the mechanic to easily determine if one of these is the culprit without tearing everything apart. For example I think I saw a video (by Sam?) where it was easy to see that the upper bushings were shot by jiggling the upper wishbone. Is there some similar way to check the upper shock mount or do you basically just assume it is and start taking things apart?

Doug

 

I think shoving a pry bar in and putting pressure on the points where the bushings are could show some play, but don't know if that's foolproof. I didn't ask my guy how he figured it was the upper bushings. As far as the upper shock mounts, I think if you look down at their shock tower in the engine compartment, the nut on each should be centered in the hole. If not it indicates some movement. Also the rubber doughnuts surrounding where the nuts are should be solid and not deteriorated. But I'm no mechanic; I don't even play one on TV.

 

Well finally brought the car in to address the faulty brake switch and a number of annoyances, one of which being the clunk.

The mechanic was able to hear the sound when going over speed bumps (like I told him to do) but when the car was on the lift and he went over all the usual things, he found that everything looked sound--NO obvious culprit. While he suspects it could be something about the shock itself, he wouldn't just arbitrarily replace it since the shocks on the XKR are pricey. The next thing he would do is set up some chassis device with microphones that helps to narrow down exactly where the sound is coming from while driving but that diagnosis costs another $200 to an already expensive bill.

There is some slim possibility that the warranty I have might cover a shock like this since it is an "active" shock rather than a typical "wear item". If so I would pursue this at a future date but if not, the hell with it--I can live with the occasional clunk.

Doug