Date: Tue, 26 Jul 2005 08:19:05 +0100 From: Grunff <grunffnospam.com> Subject: Re: 1982 900 crankshaft pulley source?
James Sweet wrote: > How does one know when these are going bad? Is it something I can check > *before* it happens? The crank pulley, or harmonic balancer, consists of two pieces of steel - an inner disk and an outer ring - with a rubber band sandwitched between them. As the rubber ages, it is no longer capable of transmitting full torque to the outer ring, so you get slippage between inner disk (driven by the crankshaft) and outer ring (which drives the belts). The symptoms usually start with a squeal on startup, and on revving etc. Similar to belt squeal. This gradually gets worse, until the pulley eventially comes apart. A good way to keep an eye on it: using white marker, draw a couple of lines on the outer surface of the pulley (the face you can see), running from the center to the outer edge. These lines cross the rubber band. If you ever get slippage, the lines will no longer line up. A quick glance at the pulley at service time will tell you if there's been any slippage. -- Grunff