Alternator Belt Adjustment on Audi 100 1990

[mboucher70 hotmail.com]

Fan belt for the alternator is supposedly tightened by an inner toothed nut which engages with teeth in the adjustment arm.  Tightening should be a matter of slackening the central bolt then adjusting the bolt to get the right tension, and finally, tightening back the bolt.

As best I can tell the teeth on the nut are stripped.  Hard to get a good look but they seem worn, and aren’t tightening anything when turned.  Any ideas where I might get a replacement?

More immediately, I’m counting on the brute force method of finding a long enough crowbar-like tool to just pry the alternator and then lock the bolts into position.  It will move...up...if I press in the middle of the belt it will move the alternator towards the slacken position, further up the adjustment arm.    But so far I haven’t been able to pry it enough in the opposite direction to get it to move further down the adjustment arm. 

Thanks for any suggestions,

MC