<E30 eta motor's> Bent pulley problems

[GREGM2002@xxxxxxx]

     I was asked to replace the cam belt on a friend's 87 325is, no problem,
I've done the belt change before. Went thru the usual steps, replaced
tensionor, water pump, etc. Car ran fine for a couple of days when I was
called saying there was a strange sound. I had the car brought over and upon
inspection found the forward edge of belt had been rubbing on the cover and
was getting destroyed. The belt was riding too forward on the cam pulley.
Thought I may have not seated the belt right, I replaced the belt again. This
time I was VERY careful about the belt location. While turning the motor over
in a reverse (counterclockwise as viewed from the front)direction the belt
would slide over into a proper location. Turn the motor over in the correct
direction and the belt would slide forward and just overlap the cam pulley. Go
back to rotating in reverse and the belt tracks back. At this point I'm very
confused as to why this is happening. I call an old club friend who works at
Seattle BMW.  We discuss the problem, he suggests I check the pulley on the
intermediate shaft for being bent, he says he's seen that happen. It made some
sense as the belt would track off the front of that pulley by 3/16 inch or so.
Rotate it and it is BENT. How that happened, I can't figure out. Never lever
on it to remove belt or anything. Has anyone else seen or heard of this?????
I've got a new one on order and will hope that is the problem. How or what
could cause the pulley to get bend. By being bent I can see how the distortion
would cause the belt to walk as the belt would be contacted at the rear edge
and be slightly pushed forward with each rotation. Reverse the rotation and it
walks the other direction. I'll repost after the replacement to let you know
if it fixes it. I sure hope so, as it's the only thing that makes any sense.
Any comments would be appreciated either privately or on the digest
Greg Mierz
GregM2002@domain.elided
Roster Manager
Puget Sound BMWACA
69 2002ti  Wa plate MPOWER

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