Whatever is, a Phenolic (Bakelite) gear. And yep, the reason they used them was because they are quieter; the alum to steel combo is noisy. The noise you should be hearing is a whine, if your hearing a clunk it's probably something else. I don’t see how your crank gear could be worn enough to cause a clunk, if it was I’m afraid your engine would be running a little rough also. It's very difficult to put an engine sound down on paper; it’s the same as trying to describe how Bruce Springsteen’s guitar sounds.
Here's a bit I wrote on the subject for a discussion on another forum:
“Is there really any way possible to communicate, convey, describe, transmit or just plane get across in print what the sound of "piston slap" would sound like, or "rod knock", or "main bearing clunk". Tappet clatter is pretty easy for most people to describe or to recognize from a description, but I think the other engine sounds in many cases are misinterpreted.
Now next to “How to Hand Form Your Own Fenders” this would probably be one of the biggest selling CD's of all time for the old car enthusiast, just think, "Those Ominous Engine Sounds in Stereo", different tracks for a four, six or eight. Start them all off cold with that crankshaft thump or is that a clunk or thud, and then run them up to a nice warm engine ping.
So all we need is a combination master mechanic/ sound engineer with the entrepreneurial spirit to pick up on this.”
Denny (Click & Clack) Graham
Sandwich, IL
