Rear tires worn weird

When I checked my tires the other day and they seamed to be fine…But when I brought my car in for an oil change they discovered that while one half of the tire was fine the other half was worn down in a peculiar way. Sections were completely bald and in other there was still some tread left. It looked like someone sanded down some parts of the tire and not others. The mechanic stated he had seen this type of thing around an entire tire but not half and half like on my tire. I asked what could cause this, he said he didn’t know and that everything else checked out.

This only happened to my rear tires, the front ones were fine. They had about 45,000 miles on them so they were due to be change but I drive 70 miles a day and I am worried that something caused this that needs to be fixed. Do I need to worry or should I wait and see what happens to the new tires?

Any help would be appreciated.

Thanks

This is a classic symptom of poor damping with a possibility of alignment also involved. It’s called “scalloping”. Since tires tilt inward as they move through their vertical travel to keep the track width constant, it’ll tend to happen on one edge of the tire only.

Get the rear struts or shocks changed (you don’t say what you’re driving) and get a 4-wheel alignment.

What you have is irregular wear. Irregular wear is caused by misalignment and aggravated by insufficient inflation pressure and insufficient rotation practices.

So the first step is to get an alignment, then rotate your tires. Putting the tires in a different position on the vehicle is going to cause them to develop a new wear pattern. However, until the old wear pattern is worn off, the tires are going to be noisy and will vibrate. The old wear pattern may take a long time to wear off and the old wear pattern might be so bad that you’ll never really get rid of it. The only other fix is to get new ones - which sounds like where you were headed any way.

So if you do get new tires, rotate them every 5,000 to 8,000 miles and check the pressure regularly - “They” recommend pressure checks monthly.

What kind of car? Could be a model related problem.