HI,

I have a strange tire wear condition on my 1999 XC. The outer tread of the tire is being chewed off at a faster rate then the center and inner parts of the tire tread. This only occurs on the front end. The rear has no wear problems. My XC is at 21K miles and all 4 outer tires are worn down to the plys on the outside with the inside of the tire having about 20K left of wear. I have taken it to the dealer. They stated that the alignment is with in specification and they can not do any more for me. Does anyone have any suggestion as to what I can do and what is wrong with the front end alignment????

Thanks,

Steven---

Hi,

A local tire shop work with me on this one and this is what we found. There is 2 deg of camber slop in the front end of my XC. The camber was measured at -1 deg on the passenger side and -.8 deg on the drivers side before we tried to move the strut towers/wheel knuckle assembly. We then loosen the 2 strut bolts to wheel knuckle and push the assembly to positive camber as possible. There was some movement but not much. We did this to both side and did a realignment of the front end (correct the toe). What we found was the camber moved from -1 deg to +.8 on the driver side and -.8 deg to +1 deg on the passenger side. When I get some mileage on the tires I will let everyone know of the results.

I hope this works.

Steven---

The conventional wisdom is that outside tread wear is caused by positive camber or by toe-in. Since the dealer says everything is in spec, perhaps both these items are at the limits of their ranges and combine to cause wear. And how alignment is measured in the shop doesn't necessarily reflect what's happening on the road. Clearly something is wrong even if the numbers don't say what. You may want to try another dealer that has a front-end specialist who is more willing to troubleshoot the problem.

Given even tire wear the Conti's should last nearly 40k miles if you go for the legal limit of 2/32 tread. But assuming that you drive on ice and snow part of the year I would be skeptical of going beyond 4/32 or about 30k miles because the traction would be compromised. My Conti's (on a '00 XC) have about 15k on them and are beginning to show a little more wear on the outside but nothing like you've described.

You didn't mention this but I assume that inflation is correct. Rubbed off outer tire is usually indicative of underinflation.

Hi Wayne,

What you stated is true, however IU have found that under inflated tires will where on both outer edges (inside as well as outside). I have only the outer tread wear. The inside is fine.

Steven---

BTW the air presser I am using is 35psi in all 4 tires.

I would think that you need either more negative camber, or more toe in. The problem with that is you would have to know which one is causing the uneven wear, because adjusting one when the other is causing the problem could make it worse. Do you drive mostly higher speed highway miles or lower speed miles around town? Does the car ever drift off track when you take your hands off the wheel? I had to drive my car for a few days with severe tow out due to an accident, and one of the characteristics of toe out that I had to deal with was the car wanting to pull or drift to either side. Toe in allows the car to track straight. If this were my car, I'd want to find the source of the problem rather than trying to treat the symptoms with harder tires, etc.

Good luck.

According to the Dealer everything is within specifications. However, my confidence in the Dealer is not very high. I had 4 front wheel alignments done over the past 2 years for various reasons and they screw up everyone! Steering wheel not straight is the biggest issue and one time the toe was so far off I could not drive the car off the dealer's lot! Now I am venting. Anyway, I have even taken it to a third party mechanic and he could not give me a reason for the excessive wear. I thought I would ask to see if anyone had a similar problem and they had come up with some ideas.

I do most of my driving around town. I drive about 25 miles a day. The car runs down the road just fine. No drift either way. I know AWD is notorious for eat tires but not at the rate I am seeing and uneven wear is not normal.

Nevermind about the drifting, I got confused about the effects of toe-in vs. toe-out. The only other thing I can think of is severe accident damage to the front end at one point, but I'm sure you'd have mentioned that.

Actually, toe-out would reduce the amount of wear on the outer tire edge. I have similar problems with tires. I keep 40 psi in the front and rear, regardless of comfort. I have 70,000 mile tires on the car and will probablyh get 25-30,000 miles out if them.

Yes, you're right. I got confused comparing my prior situation to his current problem. I had too much toe out, and he's probably got too much toe in or too much positive camber.

I'd suggest a serious look at the camber on the front end. It's worth spending the money on an independent measurement of your suspension geometry. Ask around for recommendations for "high performance" alignment specialists. We once had a 540i that we had aligned (not to correct anything) while fitting a new set of tires. Did they ever mess it up! This is at a large tire shop with several locations. Granted, Bimmers are not easy to align correctly, and some of it's not adjustable, but the independent specialist we finally ended up with did as good a job as possible and warranted his work. I had no qualms about the $50 spent, and that was in 1996... Good luck!

Our XC has the same problem. We are at 26k miles and the edges are almost bald. The center and inner edge are fine. I was told this was a problem with the stock tires.

Hi Scott,

It is not the tires. And it is not due to All wheel drive either. I know 2 owners who have the same issue. One is a V70 (1998) and the other is a S70 (1999). All have different tires (Continentals (my car), Michelin and Bridgestone). And the Bridgestone owner is on her third set at 50K miles.

Steven---

My car's mileage is currently 50K miles and have had to change all 4 tires at the same time twice already because one of the front tires have worn out. Well, apparently the front tires w/c are the primary drive tires do wear out faster as per the recent information campaign mailed by Volvo. Hope you got it. There is a rule that you are supposed to rotate the tires front-to-back/back-to-front only every 7500 miles. Well I hope my new set of tires do last longer after I follow this guideline.

I agree, however I am rotating my tires every 2k to 3k miles. What I have is a set of warn out tires with uneven tire wear. The inside of the tire has about 3/16 inch of tread left and the outside is worn down to the plys. My problem is a lot more severe then just normal V70 XC wear. I would be happy if the tires wore out evenly at 20K miles.

I did get the resent Volvo mailing. What Volvo stated in the mailing is common knowledge if you have own an all wheel drive/4 wheel drive car before. Uneven size tires can cause the front tires to bind with the rear tires when you take a turn. This stresses the drive train and can cause damage if done over a long period of time.

Steven---

I've noticed the wear you have experienced too, but not quite as dramatic.

I think the person who stated stock tires were part of the problem hit the

mark best

since it's not an alignment issue. I suggest new tires with a more wear resistant rubber, which will sacrafice a little performance, but keep in mind the way and roads one drives contributes to wear as well.