jamesm0913

Car: 2003 A6 2.7 with Tip
Problem: Driver's side front tire is wearing abnormally on the inside edge of the tread. I've STFA and found some info, but my concern is that it is not wearing out over the full circumfrence of the tire, but only on one third of the tire. The rest of the tire's inside edge is mildly worn out at worst, but nothing I would consider abnormal. I've been driving every day on a stretch of brand new asphalt at 70-75 mph and it actually makes the front corner of the car bounce sometimes, yet at times the bounce and vibration goes away and the car it buttery smooth for 5 miles. Then back to bumpy. Much less noticeable at speeds less than 40 mph.

I had noticed the wear a couple months back, along with some suspension clunking from the same side. I replaced all control arms, TREs, and sway links and an alignment was done at the dealership ($70 seemed fair). I don't know if it is just that I am tracking this problem, but it seems that the wear is getting worse now with the new parts. I don't have either spec printouts, didn't think of asking until I started searching the archives. I'm down to the cords on both of the driver's side tires, so I've ruled out one bad tire.

Any help would be appreciated, and TIA.

thejulex

Stupid question but are tires of same size...? Once upon a time, some idiot at the tire place I used to use, installed two different size tires than the other pair. I ended up with 40s one one size and 45 on the other. I never noticed until I decided I need to figure out why my Z3 is pulling left and noticed that the sizes were off. Same brand, same width, same rim size, just different height ratio... And I had weird wear pattern on one side since apparently is was driving on the edge of tire more than the other side...

Cover your bases first.

jamesm0913

They all have about 28k miles. Dealer installed for the CPO. It's scary that there are still tire jockeys still doing the mix and match thing with sets of tires! I knew better than to do that before I could even drive.

jamesm0913

I also get a rotational vibration in the steering wheel when the car starts to vibrate. When I let go of the wheel, it rotates about a couple of degrees back and forth, but the steering column does not shake at all.

tecra

Any wheel damaged / bent? Tires out of round?

jamesm0913

Thanks for the response. I had thought that also, but rotating tires after the CA swap, it chewed up another tire. It could be that both tires are old enough that it happened to them, but it seeems unlikely.

massboykie

Hey James

I had very similar issues with mine a long time ago. First they blamed the tires as they were not "OE". Turns out these were OE and they were the tires I got from them when I got the car. Everything was rebalanced and I still had the vibration at higher speeds. Took it back and it turns out one of the tires were put onto the rim the wrong way round (against its rotational direction). Tires were taken off again, rotated and balanced. That solved my issue then. I was bitching about this a lot as I read somewhere that an unbalanced Axle could cause this so I wanted that fixed under CPO if it turned out to be that.

When I got a new set of tires put on a few years later, I found out from the shop where I did it (my mechanic - Tirerack installer) that one of my rims were bend and that the were "just" able to balance it. I put this one on the rear and that worked like a charm.

Another thing to keep in mind is that the Quattro is extremely sensitive to wheel imbalance. The place I did mine does some "Road surface" (something like that) balancing and it seems to work better for our cars. Also they say that on the Quattro it's not recommended to replace a single tire. If you need to replace a tire you need to atleast do both on the same axle. I did just two last time and as my rears were still in good shape (tread wise) I think I could get away with replacing all four. Hofully someone else can chime in and confirm this.

Not sure if any of this is relavant to your issue, but I figured I'd mention it.

Cheers
Massboykie

jamesm0913

Thanks again for the response. I believe that all available info can be helpful. Can you elaborate on the unbalanced driveshaft? Did yours end up being out of balance? As I thought about the physics of it, it seems that having a heavy spot rotating on the shaft could cause my tire to wear on only 1/3 of the inside edge. My dealership was completely confused when I told them only 1/3 of the tire was wearing funny. Everything that normally causes inside edge wear wears out the entire inside of the tire. Thanks again.