truck goes through serpentine belt like paper

[earthrealm]

Trying to help a buddy out, his truck seems to have developed a taste for serpentine belts..his truck has chewed up 3 belts in 2days - less than 30miles.
the last two was fixed by the mechanic, and i helped him install the last one today, apart from one of the idler pulleys which appears to be a lil wobbly, and which we tried tightening. but its still not rock solid like the other pulleys.

any clues or tips?

 

[fdbyrne]

The wobble in the pulley is due to a bad bearing. You won't be able to fix it by tightening it. You'll have to replace it to fix the wobble. They usually get loud before they get that loose.