Re: Going thru alternator belts???
It sounds like the pulleys are misaligned. That will cause the belt jump you describe as well as the rubber dust. If the belt has been slipping alot the pulleys could also be worn so the "V" groove is more like a "U".
If you can't get enough tension on the belt, then it is probably too big, just buy the next size down.
1979 Santana 30 Tall Rig