i have an 89' f150 with a 4.9. my belt squeaks everytime i crank it. when my dad had it he replaced the belt (about a year ago). he cranked it up an squeaked an ripped the top layer of the belt off an slung it in the engine bay. so any help would help alot!!!

 

How much play is in the belt? Is there anything that is rubbing against it?

 

Yea, if there's too much play the tensioner is going bad, but I'm thinking that an idler or even an accessory is siezing up.