(06 Elantra)I got hit a while back on the passenger side rear tire. The top of the tire was touching the strut. It was the day before I was deploying, so I had my wife drop it of and pick it up. When I got back from deployment (7 months later) both rear tires had severe tire wear (cupping, flat spots). The wear was very uneven. It looked like she pulled the e-brake doing 70mph multiple times. The right rear tire had collapsed and was almost touching the strut again. I took it to the shop where the repairs were made, they had contacted the suspension work out. Suspension shop said when it left their shop it was in alignment. They showed me the specs, and it was in (I know people can cook the books). Anyways they said my struts were to blame and not their work (even though they had replaced one strut 6 months prior). So I replaced my struts and tires and took it to a different shop for alignment. They had to use a camber bolt in order to get it into specs (which led me to believe the other shop didn't do the job right the 1st time if it now required a camber bolt). Anyways, shop #2 got it back in specs, and slowly the passenger side rear tire began to wear with cupping an flat spots again. Had to get a new tire to get it inspected. I ordered an alignment tool just to check it myself, because I am puzzled now. The drivers side rear shows about -2 degrees, and passenger side shows about -1 degrees. Only 1 degree difference. So I measured for toe, with respect to each tire. The front of the rear tires was 1/8" closer than the rear.

So can 1 degree camber difference and 1/8 toe in cause a tire to cup and have flat spots? Or could it be something else? Could a coil spring or both be bad? I didn't replace them with the struts, just reused them. I don't want to keep replacing one tire every year.

 

Taken from a Subaru forum: "Camber bolts are most often used for accommodating manufacturing variances or returning the alignment to the correct specifications after a suspension component has been bent in an accident (hence the slang "Crash Bolt")."

Its possible that during the accident, one or more of the suspension components were bent in that quadrant of the car.. rear lateral arm, trailing arm, etc. You would need to replace these to get the alignment true again. Until then, any alignment procedure is compensating for these bent components. Try any of the junkyard parts networks online. You might be able to find them cheap. I did, when I had to replace a crossmember due to rust.