In checking the atmospheric recovery bottle, I removed the right front tire and discovered this:



And in case you are wondering.....pictures are of two areas, not the same one twice.

Gee....think there is an alignment issue!!
I know the rear camber is out; never have replaced the factory shims with thicker ones....but now the front.
I did notice that the top shock bolt is no longer centered in the hole....I have replaced the upper mounts with the poly ones....looks like I get to do this again. Thought that was one job I would never have to do again.

 

You, me and a hundred others . Lol.

 

Shot of the right side, same side as the tire above. I can see no deterioration of the upper mount on the outside. I assume it is the inside ring that has failed; correct? Will need to get the spring compressors to go any further.
And of course...which upper mount to get....another Welsh or the URO one?????

 

Stay away from URO parts - they are known to be of poor quality. I would install another set of the Welsh components....

 

I suspect that wear is more likely due to toe out.

 

That one does not look like the failure I had where the center bushing crumbled. What does the large outer bushing look like?

The tire wear you had does not seem like it could be caused by a failure of the center bushing which essentially secures the shock absorber. It does look like a collapsed outer bushing would cause it, or a general misalignment if the outer is not collapsed.

If you do need to replace the mounts the Welsh ones are still better than any known alternative even if they don't last forever like we hoped..

 

At the same time that I replaced the upper shock mounts I also replaced the upper control arm bushings with poly bushings. In removing the fulcrum bolt, the forward sleeve of each poly bushing came out with the fulcrum bolt. I had to hammer the sleeve back into the poly in order to get the fulcrum bolt out. Once I had both fulcrum bolts out along with the forward sleeve, required hammering the sleeve off of the bolt....it would not easily slide.

On the left side, forward outer poly bushing, the center hole was a bit distorted, no longer round. All the other appear to be in pretty good shape...but they only have 35k miles on them.

Decided to replace the poly bushings, go back to OEM. Will need to check each fulcrum bolt for any nicks or raised areas, give them a good sanding before re-install.

Have not got the spring compressors yet to see what has happened to the Welsh mounts. The outer rings look perfect on both sides. Will post pictures of the inner rings once I get then apart. Which will not be until the new ones arrive as I have to borrow the spring compressors, only want to do that once. Hopefully this weekend.

Once all back together, then straight to the alignment rack.

 

Follow up on post for Welsh Poly Mounts--
Update on Welsh Upper Poly Shock Mounts/ New Front Springs. Measured the Right side this AM to see if any problems was evident. They are still at 15 5/8" roughly from W/O Mldg to hub center. Installed Sept. 2015 and 28K miles traveled. My tires were wearing quite a bit on the inner edges, but they show no additional wear since. Apparently the Front Springs were sagged. My center bolts have moved off center, but no deterioration is evident.

 

To add to the above post, Wayne (cjd777) and I installed the Welsh poly front shock mounts (along with new Bilstein shocks) on my wife's 2006 XK8 in early January 2016 as the vehicle was approaching 99,000 miles. It now has 120,600 miles and the Welsh components are holding up quite well. The center bolts remain dead-center and the center hub-to-fender edge measurement remains at 15.5 inches. I had the "Brutal specs" alignment (setting the front toe to .16 on both sides instead of the more typical .12) put on the car in late September 2019 and it tracks perfectly with very even treadwear. Almost never driving this car at night means that its pothole avoidance scale is nearly 100%....

Granted, this car has not been her daily driver since late October 2018 so it is no longer subject to the everyday stress and strain that it was from acquisition in early February 2012 to it becoming basically a toy in late October 2018. All things considered, I remain very pleased that Wayne and I opted to go with the Welsh components instead of the poor-quality OEM foam....

 

I got one shock mount off today...the other one is STUCK! And the spring compressors I rented are too large, will not fit between the coils. Anyways I took one Welsh mount apart to find out why the shock rod was no longer centered.
I found that inner ring is actually like a doughnut, comprised of three parts; two poly and one metal. The main issue is that it does not fill the area so it is able to move/shift, and no longer be centered. An easy fix would be to simply make this inner doughnut larger and fill this area.

Some pics:




The inner "ring" can easily shift to be up against the inner surface. I noticed that the poly was a bit deformed or crushed where it was up against the inner surface.

 

use a gear puller with three legs to force shock out of mount

 

Yeah a 3-jaw puller will work. I just do not know why it is stuck and what is holding it on. Waiting for spring compressors to arrive.
Also I agree that the off-center shock mount is unlikely to have caused the tire wear; I think it was the upper control arm poly bushings. To me the poly is too soft and the inner sleeve thickness is not near enough...about 1/3 of the URO bushings I got. New bushings are in the control arms, fulcrum bolts are smooth, ready to go in, new tires are mounted/balanced.....just need those spring compressors....hopefully by this weekend.

 

I had to do the same. The Welsh mounts have a slightly smaller pass through hole which binds on the shock rod. After removal I cleaned the shock rod with emery paper and it slips into Jaguar mount with just a little nudge. Will not go into Welsh mount freely

 

I had no problem at all when I installed the Welsh mounts in 2016 along with Bilstein shocks, slide right on, no problem at all. The one I did get apart, the spring had no problem at all shooting the shock mount out...along with my 19mm socket, the nut, my1/2" racket.
I am curious to see what is holding it....once I get the spring compressors on it...........

 

I had the same binding problem with the Welsh mounts when I removed the failing set.

Did not have a problem with installing the replacement set but I also replaced the shocks with new ones at the same time.

 

I did have to use a 3-jaw puller to get the mount off. Found the problem to be that either the Bilstein shock rod is a tiny bit larger than OEM shocks or the bushing hole in the Welsh mount is a tiny bit too small. It is the area between the shock rod shoulder and where the threads begin, it is almost a press fit. I decided to enlarge the bushing hole in the new Welsh mounts a tiny bit so that the mount slides on and with minor effort goes down to where the bushing rests at the shock rod shoulder....like I think they are supposed to fit.

 

Thought I would update this thread:
Received replacement pair of dish washers that I had tossed-out by mistake. Everything together now....new Welsh upper mounts, new URO upper control arm bushings, caster shims in correct locations, new front tires, rear tires re-balanced. Also from another thread....I replaced the OEM 4mm rear camber spacers with a 6.0mm and a 6.5mm spacer, lube all four U-joints.

XK8 is sitting on all four tires....first time in about 2 months....yeah!!!

Next week taking in for a four-wheel alignment....curious to see if the rear camber is within spec or not.....probably not....but hopefully better.
I will post the alignment numbers when I get them.

Next task is to do a trans filter/fluid/seal change....but think I will wait a bit....it is like 111°F today....just too hot to be in garage for long.

 

Return from getting the alignment with the following results:
LF: Camber -0.5°, range of -0.2° to -1.2°, mid of -0.7°. Toe 0.13°, range of 0.04° to 0.21°, mid of 0.13°
RF: Camber -1.0°, range of -0.3° to -1.3°, mid of -0.6°. Toe 0.12°, range of 0.04° to 0.21°, mid of 0.13°
LR: Camber 0.0° range of 0.5° to -1.5°, mid of -0.5°. Toe 0.22°, range of 0.08° to 0.25°, mid of 0.165°
RR: Camber -0.5° range of 0.5° to -1.5°, mid of -0.5°. Toe 0.19°, range of 0.08° to 0.25°, mid of 0.165°

First time I have ever had all measurements within spec range.
Right front camber not all that good, left rear camber....the new spacer pushed it out a bit too much. Post #17 above should say 7.5mm spacer, not 6.5mm on the left side...which was a bit too much.

Will see how the tires wear now....

 

Good results. Nice to see your rear calculations were very close.

 

Before you go nuts and potentially waste a lot of time and effort, to me the tire looks like it's failing due to a manufacturing issue. It looks like a retread that's failing. You have to replace it anyway so get the tire shop to give you their opinion.