My 1984 190D has started to make a high pitched squeal and it seems to be emanating from the serpentine belt tensioner apparatus. It looks like there are 4 parts ( 2 shocks, a pivoting tensioner and a pulley). I'm guessing the pulley is at fault here. The service manual for the 601 is in the mail and hopefully I can diagnose from that but I'm impatient and wondering if anyone can give some info from experience so I can go ahead and order the necessary parts.

Thanks

Kevin
1979 240D manual
1984 190D manual