My rear tires keep wearing on the outside I put tires on the back every 3 months. I was told to replace my wheel bearings so I did it didn't fix the problem. The tech at the tire shop in town said to take it too muffler man and have them do an alignment. I called for a price and they said it cannot be aligned because it's front wheel drive and it's the rear end I'm having problems with. What else can cause the tires to wear so fast.