The Stovebolt Site Forums The Shop Area Driveline Fly-wheel, Clutch Question.

I am in the process of replacing the clutch and pressure plate. The clutch got to chattering REALLY BAD. It was so bad I thought I was going to break something.

The old clutch plate looks fine. Lots of meat. The pressure place is really smooth.

The fly-wheel is smooth as glass. If you pull a fingernail across the surface, it doesn't catch your fingernail any where. Visually you can still see evidence of the previous fly-wheel re-surfacing. It's like it has been polished.

My question is:
Should I re-surface the fly-wheel again? I did it with the previous clutch install because the fly-wheel surface was rather rough. Or is it something that should be done with each clutch job?

Post some pictures of the flywheel surface please. Something was causing your "chattering" and a visual look at how it is looks is much better for fellow Bolters to offer their experience and expertise.

It might be warped. Have you laid it on a sheet of glass or laid a metal straight edge across it in all directions?

Look for a worn pilot bushing, and/or deteriorated motor mounts. If the flywheel surface is smooth and doesn't show cracks or heat checks, use a random orbit sander and some 40 or 80 grit sandpaper to break the glaze on the disc contact area. Chattering on clutch engagement is often caused by broken or damaged motor mounts.
Jerry

I had that happen to me. When I replaced my clutch the man at my favorite FLAPS found the listing showed the 10 inch clutch disc being unavailable, but with a note that a 10-1/2 inch would fit, so I bought that. I too soon after got to the same place as 54Belair and took the not old clutch out. The flywheel and pressure plate are still smooth, but a young man noticed a ridge all around the edge of the 10-1/2 inch disc. My flywheel surface diameter is 10-1/4 inch ,so I had a 1/8 inch overhang all around. I ground that ridge off but did not reinstall that disc. I bought a 10 inch one and installed that with my same flywheel and pressure plate surfaces. That fixed the problem for me.

For the amount of work, it is to replace a clutch and pressure plate, I have the flywheel resurfaced as cheap insurance to having to do the job again. It also eliminates any hot spots that are generally found on a used flywheel.

If the flywheel is "smooth as glass" and "like it has been polished" it is possible it has become glazed. First...Please make sure you're not getting oil leaking from the rear main seal that runs out on the back side of the flywheel, spins up and across the top of the bell housing and drips down on the assembly. If oil is present on the back side of the flywheel, centrifugal force definitely can cause this to happen. You'll also see oil in the bottom of the flywheel cover and you'll have already identified a notable oil puddle on the floor below it.

Second, Please look for any discoloration (usually bluish, dark gray or occasionally purplish) on the flywheel and pressure plate. If it is mirror-like and feels very hard, that's glazing. Also look for cracking lines (pretty common on flywheels this old but not usually incorrectible)...generally they'll be just in the contact area. As Jerry said you can use an orbital sander to break up glazing. A professional resurfacing is the best way, of course. If oil leakage happens to be the problem, toss the clutch disc, please. I've never seen a way to remove oil from one of those and not have it ruin the flywheel if it gets re-used.

The old school, country boy method to deal with an oil soaked clutch disk. With transmission in a fairly high gear, slip the clutch...a lot, do it till it stinks. I just did same on my '51 after replacing the leaking rear main seal that had leaked a lot for at least a year. The chatter finally got to the point the truck was undriveable.

I have a pretty good small hill on the road to the shop. Stopped at the bottom of the hill, put transmission in 3'rd and slipped the clutch while the truck moved at a few feet per minute till the stink was very bad. I'm sure there was a lot of smoke rolling if I'd been looking.

I did sacrifice some clutch disk material but all the chatter is now gone and since I've not quite put 10,000 miles on the truck since replacing the clutch 10 years ago, I'm betting it'll be fine as long as I'm driving it.

RonR