This is one I come across far too frequently. This alternator was replaced and the replacement alternator shipped with a 1/2" pulley. Why is that bad? These engines use a 3/8" belt!!!!
No matter how much you tighten this belt it is going to slip and create belt dust, because the belt is too small for the pulley!
Multiple attempts were made to fix this issue, at a decent cost to the owner, and not a single technician noticed the wrong sized pulley OR THE ALTERNATOR BRACKET....