Has anyone seen the inside of their front tire wear so bad that it actually rips? I had a relatively new pirelli fail today. It had about 70% tread left except for the very edge on the inside. I have had my beast for 2 months now and this is the second tire fatality (ran over a nail on the rear tire and ruined it before I could get to a filling station). The car tracks very nicely so I had no reason to suspect the alignment was so off. Is this a common problem?

Pete
04 XKR convertible
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Have you had the alignment checked? Sounds like it might be towed out...
Regards,
White Bear.

 

I had exactly the same problem with my Pirellis, though perhaps not quite so dramatic. Both rear tyres had about 30% tread left, except for the inside 4cm which were completely worn smooth. I replaced them with Michelin PS last month and am keeping a close eye on them. I suspect excessive negative camber.

 

The toe and excessive neg camber will do it every time. Trust the dealer only for a proper alignment, trust me. Sagging upper shock mounts will lower the front suspension and adds to the camber issue...check the crumble quantity up top and/or shock bolt being off center of the tower.

 

I would add to the forgoing:

When you buy a used car with good tires that you want to keep - get the alignment checked. It's cheep insurance. Around these parts an alignment cost $150/$225. A new set of quality tires runs $800/$1100. It ain't rocket science.

 

I have had the same problem, and although Pirellis wear worse than any tire I've ever seen, it's not the brand of tire that's the problem. I tried to have an alignment done but the camber was off too much to bring it into compliance. I have had a set of camber "shims" made that will be installed soon as a have a chance to get it into the shop as I don't want this to happen to my new Nexens.

 

A lot of members, myself included, seem to complain about the excessive negative camber, but where can these mysterious shims be sourced? Can any competent mechanic do the work, or is it a dealer-only fix?

 

You can buy them via Jaguar, or have them made. Measure the current shims (mostly they are 4mm), then measure the current camber (make sure the fuel tank is full). Then its about 0.19 degrees (decimal) per 0.5mm, that will get you close the target you like.

 

I just have a basic alignment done every 3-4 months or so as only costs £15 on half-price special. Have done this for 3yrs and no uneven wear.

One thing I do find is that the under/over inflation sides/centre wear differs from tyre to tyre, so under for one brand will be fine for another...a complete PITA when changing brands.

Luckily have aftermarket TPMS so can keep a track on pressure changes.

M

 

I am unaware of any 'camber shims'. There are shims on the upper A arm pivot bolt, however, they set caster. And there is an eccentric bolt for the lower control arm which provides a half degree of camber adjustment. But I have never seen, nor heard of, a camber shim. Pls advise.

 

The Camber Shims (actually spacers) are used on the Rear Half-Shafts to correct Camber on the Rear Wheels.

 

The rear wheels...OK... now I understand. Thx Paul.

 

Heavy wear on the inside edges is usually a sign of lower ball joint wear. These are heavy cars and are pretty tolerant of wear to the bushes etc. but you will suffer excessive tyre wear. Get them checked by someone who knows

 

^^^ While a loose ball joint can be and issue, the car would be all over the road and couldnt maintain a straight track. Your issue is more toe out too much WHILE DRIVING, not neccessarily on the alignment machine. You drive down a road which pushes out on the tires toeing them out more which is why Mercedes wants a pressor bar used when doing an alignment to simulate what the suspension does while driving. And why I set toe in to the inner most setting in front. Check it and comphensate for it while doing an alignment. They dont know what this is? Inform them or go somewhere else, its not rocket science. And camber will not noticably wear inside of tire till it goes above -1.5, closer to -2.. And Matt was correct on checking the front upper shock bushings for deterioration. They drop ride height and camber goes right towards -2.

 

Brutal
Thanks for the toe out tip. I have an appointment with my alignment shop here in Clearlake and will have them check and set the toe. As far as the top shock bushing goes, can I inspect that from the top side in the engine compartment or do I have to look up from the bottom of the car?

 

Wc, if you want to spend a few hours in houston, try getting an appointment at Momentum Jag, and request your favorite tech...you know you'll get the best alignment, and an evaluation of that mount. Oh, shock mounts inspected from the top.

 

But you cannot see very much of the front shock mount when inspecting it from the top, so what are we to look for? The "crumble factor"? Something else?

 

since youre in houston why dont you come see me. Ill make it worth your drive and i have to work this sat. Pm me, maybe jim or one of the mods can upgrade youre status since you only have 3 posts.

 

Brutal
Thanks for the invite. Cant make it this weekend but I will definitely put it on my calendar!

 

Both, if you rub the material uptop around the shock stem with your finger and it crumbles easily, its bad.