like I said check this out.
http://www.vwdieselparts.com/forum/viewtopic.php?t=8173I have made my own a little differently, but not in full use yet as my alt is needing help.
When the bearing went out of the back of my alt. it would sometimes squel, even at ldle, sometimes it won't. And you really have to torque on the pulley to get it to move up/down...all with the belt off. It got so bad before I figured it out that the fans on the alt. would stop the alt from spinning and it burnt a spot in my belt and it shreded/snapped. I had tightend it like crazy before trying to get the noises to stop no luck. I thought it sounds really familiar to yours, but it could be way off. I would yank that guy off there and have it rebuilt, just in case.

PS...you'll see my post under yours about my current alt. delema :evil: