I just noticed yesterday that both of my rear tires are bald on the inside edges!!!

Wat would cause this? Shocks, bushings, bearings etc.??

I have a warrantee on the car, but it has a $200 deductible and i like to have a guess as to the problem before I take it in.

Thanks in advance for all the help, i know it'll be forthcoming!!!

 

like the front, the rear has a little negative camber designed into it...the lower the suspension and body is, either by adding 'lowering' springs or just aging OEM springs, the camber will increase as it droops. Unlike the front, the rear can have shims added (dealer has shim kit) that will get it back into spec. You could do this yourself also, and prolong the rear tire life...but a little bit. The rears always seem to go faster than the front no matter what we do.

What tire pressure you running in the ***-end?

 

Thanks for the insight...

About how much is it to have the shims installed and have it re-aligned? The rear suspension components should be covered under warrantee, but not sure if the alignment would be covered. I wonder if I could prove to them the springs are worn out of tolerance and get them to replace them???

To be honest, I have not checked the pressure (I know, i'm bad...) They are the BBS wheels and I need to take out the plugs and screw in the valve stems to check them. I'll do that this weekend and see where they are at. Have you got a recommended pressure handy?

The tread looks really good except for the inside 1-2" or so. Can the tires be taken off the wheels and reversed so that the bald spots are on the outside and I can run them longer?? (still have them running the same direction down the road) They are the 20" x 10" Pirelli's and are not cheap to replace...

 

Any more help here?

How difficult is it to adjust shims and what tools are used for calibration??

 

I paid the dealer to do it. Here is a good thread that describes the shims and how to install them. Can't be that expensive at the dealer.

 

Update...

Tire pressures were all good, 32-34 psi.

I've got an appointment with the local Jag dealer on Monday. Four wheel alignment is $130 and if they have add the rear shims as I suspect it will be a total of $340.

They will also do a thorough inspection first, and if anything is broken or worn out, I will have to go back to the other dealer I purchased it from and go through the extended warrantee process.

I thought the dealers alignment price was fair??

 

very fair, mine charges a flat rate of $189 for a 4-wheel.

 

In regards to your question about turning the tires around to even out the wear, just take both tires off and move the left tire to the right rim and vice-versa. That will keep them rolling in the same direction, but the worn spot will move to the outside of the tire rather than the inside.

 

Don't forget the long bolt going through the lower wishbone at the rear is also eccentric which also gives you wheel alignment adjustment

 

The XKR's call for toe out on the rear. This is nice for handling at extremes but wears out the tires quickly. Get the alignment shop to set the rear for 0 degrees and you should be fine. I just got 35,000 out of the rear Pirelli P-Zeros on my XKR with this setting and it handles just fine.

 

Thanks for all the great tips!!

Will have them set it at 0 deg toe out.

Rev -- That's exactly what I was thinking!

 

Latest update, hopefully beneficial to others...

Got the cat aligned at the dealer. Turns out it was the rear toe in, not camber that was out, and not really that bad. Possibly at some point the camber was out and caused the wear, but not at this time.

Alignment price was fair, $130, but was promised a wash n vacuum that didn't come thru.

Could not convince the service tech that swapping the tires on the rims would keep them rolling the same direction!!! He just kept insisting you'd turn them over and roll them the opposite direction. I finally gave up...

SOOOO -- looking at new rear tires... It prolly needs them regardless. Found them locally installed, $930 for the pair installed!! Called two other reputable shops and both were at $1175. Looked at Tire Rack and the tires alone were $960. All of these are the Pirrelli Pzero Asimmetrico 285-30 20" rims, 99Y rating. I looked for the Conti DSW's that everyone loved in the other thread, but they are on a 'national back-order' with no timetable for availability!! Are they produced in Japan???

 

I have a low tolerance of idiots. I wouldn't have argued with that service tech, I would have just told him exactly what I wanted him to do, and when he tried to tell me the tires would be rolling backwards I would have told him "I don't care". Then, he probably would have flipped the tires over when switching them from side to side, and the worn spot still would have been on the inside. Then I would have made him take the tires off and flip them over. That's why I like my tire place with the big windows. I can actually watch them and stop them if they are doing it wrong.

 

Amen Reverend!!!

The tire place I'm going to (Hibdons), is all glass from the lobby to the service area, all the overhead doors are glass and they are usually up!! I will keep an eye on those BBS rims the whole time!!!

On a separate note, the Lincoln was in the shop for minor warranty and service work. When they were test driving it after a transmission reprogram they had a rear tire blowout!! 17k miles on them now, and they were in great shape. Luckily, nobody was hurt and no body or rim damage either. They put a new tire on it for me and comped the oil change / tire rotation...

 

I always tell any dealer or mechanic exactly what I know and what I want done. For some reason Jag mechanics enjoy that their owners are so into their cars and usually gets them to start talking and I end up going over all the known pre-existing issues telling them what I already know is wrong and what I plan on taking care of. I usually never get solicitations to 'fix' things that don't need correcting. Except today at the generic tire store "oh, you should get an alignment with those new tires".... um... No. At least not there. lol

 

silverstone: sorry if this is a dumb question but do the tires you have on the rear now have an inside and outside? if so, you can't move them the way you want to.
I just bought the DWS's, go to a Conti tire dealer, they can get 'em. I paid a little more than at tire rack, but not much. also got them to throw in a road force balance

 

What was the toe before adjustment?

 

Have you considered that when someone cannot see what it is that you want that maybe the explanation is inadequate?

Go back to the original description of the "flipping" earlier in the thread and you will see that it takes a couple of readings to decipher.

A person who encounters a lot of "idiots" ought to look to how they explain things.

 

A person who works in a tire store should not need anyone to explain how to move the outer edge of a tire to the inner edge while keeping the tire rolling in the same direction. The tire "professional" should already know how to do it. If he doesn't, he's an idiot. The exception would be if the tires were asymmetric as beauregard explained above. Silverstone didn't say what type of tires he had, and asymmetric tires are relatively uncommon. A tire professional should be able to adequately explain the reason why asymmetric tires couldn't be swapped from side to side in a manner that a layman could understand. If not, he's an idiot.

Is this what you had to read a couple of times to decipher?


I see what you mean. I guess when I say "I'd like a Big Mac with no onions" it's my fault if the person behind the counter can't figure out where the "no onions" button is. If only I had done a better job of asking for no onions. I've always wondered why some people can't understand the simplest things. Now I know it's MY fault! Thanks!

 

Whew, lots of questions and I learned a lot today.

First off, after further examination of my original Pirelli tires, which may be special on the Silverstones...

The fronts are 'Direzionale' or directionals that have an arrow on them showing the required rotation. 255/35 ZR20 97Y J. They have matching treads (symmetric) on the inside and out.

The rears are/were 'Asimmetrico', are marked with inner and outer and must be mounted correctly on the wheels. 285/30 ZR20 99Y J. The dealer was actually correct (since you always want to keep radials rolling the same direction), but never mentioned this aspect and seemed rather arrogant at my suggestion rather than better explaining the situation...

Went ahead with the new tires through the local? chain tire store, Hibdons. Tires came in on truck at 2:00, day early, made appt for 2:30 and was done by 3:15!! Excellent service, no damage to wheels and all around good experience!!! One note, it took almost 60#'s of air to seat the rims. The tech seemed surprised?? Said they were shorter and wider than vettes, and the short profile is not flexible... I stuck with the Pirellis because I was keeping the fronts.

Still not confident in the alignment, now that I look at it, the report has the wrong VIN # on it!!! Right make, model, time and date, so not sure it's the right report... The #'s on it are:

On the rears, Camber L -0.7, R -1.0; allowed is -.0.9 to -0.1 they set it at -.8 and -.9, almost the max!!! Resulting in barely an adjustment???

Toe (which the tech said was the problem) before was L .25, R .30, total .55. Allowed is .1 to .25 each .15 to .50 total. Final was .1+.15=.25 total. Again, not much of a change, but these are now set near the minimums as recommended by Dick.

Funny thing is the front L toe was at 0, R was 0.3 when allowed was 0.05 to 0.20, both out, but not on total... There was no noticeable wear on the fronts.

Now my questions!!!

1- what does 99Y or 97Y and the J mean on the tires?

2- was the rear toe really the problem, a bad report, or maybe it was aligned AFTER the tires were worn?

I'm planning on keeping a close eye on the wear and look for a new place for an alignment!!!

PS--noticed the pinched off exhaust in front of the rear axle for the first time!!! Wow! Surely there was a better approach than that!!!