I was doing a car show today and when I opened the hood I saw the pulley for the alternator had self destructed and torn it's self to shreds. Luckily it lasted till I got home, but the belt is only about 500 miles old. It basically came apart and unraveled. The power steering belt is still perfect and I replaced then at the same time.

I was wondering if maybe over tightening it could cause this sort of premature wear??

The alternator is one of the aftermarket PowerMaster units Summit sells. It has been on the car for about 8 years and this is the first time i have had an issue like this. I use only the good Gates brand belts too.

Any ideas??