Last year I replaced the front upper shock mounts with an aftermarket set (I don't recall where I bought them from) mounts (the black rubber kind that rivets together). I didn't realize I had a problem with severe tire wear from negative camber until it was too late.

I thought it might be coming from worn lower shock bushings but I noticed a black tar-like substance behind the shocks. When I took off the caps on the shock towers I was shocked to see that the rubber had completely extruded through the upper opening!



Looks like this on both inner sides of both tires.



Rubber material pushed through the top and sides of mount.



The distance from the lower fender lip to the center wheel cap is 13 3/4" on the right and 14 1/4 on the left side of the car.

Question: Is the loss of height from the faulty mounts enough to cause such severe negative camber and tire wear? I'm really upset that I didn't catch the wear sooner (less than 5000 miles on new F1s) and what I thought was an improvement on OEM mounts failed so spectacularly! Anyone else have this happen to them?

 

You are the second one that has seen Melting Mount syndrome.


Hemitwist was the first


Appears to be the same vendor.

 

So the shock mounts sourced from PartsGeek are the problematic ones?

Wayne (cjd777) and I installed the Welsh Enterprises poly shock mount kits on my wife's 2006 XK8's front axle back in early January. I'm not seeing or feeling any breakdown from them as of yet and I certainly hope they do not disintegrate like the PartsGeek shock mounts apparently do....

 

The crap ones from PartsGeek are not the melting goo type. The PartsGeek ones just crumble like this within a couple years:



Seems like going aftermarket is a risky bet for these. I hope the Welsh versions hold up better as they seem to be the only choice we have now other than OEM.

 

Motorcars Ltd are the Melty ones. Parts Geek are the Crumbly ones.


My Welsh Ent mounts seem to be holding up fine.

 

Glad to hear that, I have a pair I was going to fit this week, luckily from Welsh.

 

Hmmmm .... sounds like a donut to me.

Parts Geek is a supplier, the other thread mentioned that theirs
are branded "Eurospare".

The Motorcars version seems like someone decided to mix tar
and bits of foam. The wheel wells look just like tar based
undercoating. Tar + heat = not good.

Of the two, the Motorcars version is the most deceptive.
In fact, I would call them counterfeit and not very good
ones at that.

If sold in the UK, they would easily fall into the distance
selling provision for "not fit for purpose". That leads to
immediate refund of purchase price and shipping.

The Eurospares version may also fall into that category,
but would take a judgement call from the regulator.

 

Sounds like we need to get the word out to buy these kits ONLY from Welsh Enterprises. Perhaps create a sticky thread at the top of the XK8 forum about it?

 

The Motorcars version of the upper shock mount bushing is so
bad, I would be looking for reimbursement on the tires and cost
to clean the wheel wells.

The Eurospare are poor quality, the Motorcars may fall into the
fraudulent category.

 

Motorcars on yelp.com

anybody can be anything on the internet. take a look at the size of
the building at the top of the page before proceeding downwards.

https://www.yelp.com/biz/motorcars-houston-12

 

We have not noticed any apparent problem with our Welsh Ent. Poly Mounts either. They are holding up great and suggest if Poly Mounts are what you desire, get them. Welsh Ent. seems to have a quality product.

 

I bought from partsgeek four years ago and they still look like new, nor has my ride height degraded, so the supply they had at that time was good.

 

Bought the Parts Geek versions in May 2014 and have about 30k miles on them.

They appear to be just starting to crumble. I have noticed some minor flaking when looking at the top of them from inside the engine bay. No noticeable change in ride height yet.

Would love to go poly when they finally give up, but now I'm not so sure.

 

Is the failure of the shock mounts enough to cause the tire damage or should I be looking for something else? Visual inspection seems o.k. at this point.

 

As the shock mounts disintegrate, the geometry of the suspension changes and that can indeed be enough to ruin your tire tread (particularly on their inner edges). But you may have other issues as well. A thorough inspection is called for to determine if you need additional components. And you'll definitely need a fresh alignment after the new shock mounts are installed....

 

A failed lower shock bushing also causes the suspension to sag (the spec book has a reference ride height) and push the camber out of spec.

 

Out of spec toe can also cause heavy wear, especially combined with failing shock mounts. Get the alignment checked when it's back together.
fmertz offered good advice about the lower mounts. I just replaced the rear lowers on my 97 using a 6" bench vise. They were $31/pr including shipping from British Parts International via ebay.

 

I would be surprised if the mounts caused that much wear. I'm sure someone here knows how much they affect ride height but I'm guessing no more than 3/4". Tossing fat Aunt Betty in the passenger seat would do the same, so I'm thinking you have another issue.

 

Less than a year old!

 

Motorcars LTD is a frequent contributor here on the forum, correct? So what do they plan to do about these terrible shock mounts they are selling?