Hey all,
I just had our WRX ('02) fixed at the dealer (my GF ruined 2 rims on a curb and bent the left side tie-rods). Now I had to install one new tire--the others were within the 'AWD spec' (1/4"+ thread depth on the others). Problem is after taking hold of the car from the dealer, it's got a 70+mph vibration in the steering wheel. Gets worst when coasting (above 70).

Not being familar with AWD systems, does this sound like your typical alignment issue or is the AWD doing something I need to be aware of? (taking it back to dealer BTW). Thanks.

Sounds like a balance problem rather than alignment. Take it back and have them spin the wheels up on the balancer.
Also the 1/4" spec is for rolling circumference, not tread depth.

You should have had at least 2 replaced and replace the other two shortly. If she damaged the rims, one could be bent causing the vibration. Have them dismount the tires and see if the rims are bent on all tires.

If you keep one odd tire, even two on for too long, you can damage the AWD

Did the dealer mention this? Or did you only want to purchase one tire?

Thanks for the suggestions. FYI, the rims (2) were replaced with brand new OEM rims (1 new tire was needed tho). Everything was spun/balanced, etc.. so I was thinking they were ok--also, forgot to mention it does pull to the left coasting at speed. Tire rack mentioned that I needed >7/32" tread depth to be within tolerance, which I have (1/4"-9/32"). The old tires are fairly new BFG kdws's...

I just read that the front diff is mechanical (i.e. non-viscous), so doing 2 new tires (in the front) sounds like a safe bet. Unfortunately the dealer was not much help when I got the tie rods replaced--they actually recommended that I "need a new spare tire" for one of the damaged rims sitting in the trunk :rolleyes:

If it pulls to one side it may need an alignment, this should have been done after the tie rod replacement. It could also be from the differences between the tires even though the tread levels are close. Are they exactly the same model tires?
You can verify if it's a tire problem or not by swapping wheels left to right and seeing if it then pulls to the other side.

Yep. replaced w/the same tires. I'm not sure if they actually did an alignment (?) or just set everything to spec... I'm going to try swapping the tires before I take it in again.
That's what I was wondering: if the AWD could be doing something weird with the mismatched tire (though w/in tolerances). When coasting in neutral (out of gear @70mph) it still pulls, so I thought it's got to be alignment or balance.

2/32nds of difference worries me, because according to my calcs, that leads to 0.4 inches difference in circumference, which is well over the recommended max 0.25 inches difference in circumference. I'd keep the 2 original tires that are closest to each other in tread depth, buy a 2nd new tire, and have both new tires shaved to match the 2 original ones.
Another thought: if two rims were trashed, did the sidewalls on those tires get damaged, too? Maybe both tires from that side should be tossed instead of just one - sidewall damage isn't good.

Thanks everyone for their insights. I remeasured the tires tonight and the left front has the lowest tread depth: 7.25/32" avg. vs the brand new tire (right rear) at approx 9.25/32" avg. Other 2 tires are somewhere smack in between. I ordered a 2nd tire and will play around with the balancing and position of the 2 new tires. Looking into where I can shave these things too [locally] if I need so.

Funny thing is when I assessed the damage (before buying new rims, etc..), the original 4 tires wore unevenly as well... (tires were 6mos old). Luckily no one is driving the car this week...