[silverbullet07]

I have been having a problem with my clutch chattering a little pulling out from a stop. This only stars happening after about 20-30 mins then it sometime starts up at redlights.

The flywheel was resurfaceed 3000 miles ago. New clutch components in then too. The transmission is a m20

The first 1500 miles or so, there was a 2.73 rear gear in it and had to slip the clutch a lot to get the car moving. Had the rear end built with a 3.36 and that is when I started getting the chatter.

Pulled everything out today. Thought I would post some photos of the flywheel. Looks like it is toast. Does it look like it may have caused the chatter? Did not see any other issues really.

[TedRamAirII]

I think you found it. Hot spots. Get it resurfaced. As for the PP, it looks ok from the pics, usually it runs hotter than the flywheel. If it has any hot spots, you may be able to smooth them off with fine sand paper. You can run your hand across it, if it feels smooth, its good to go. The disc looks ok.

[tom s]

the disc looks glazed?Tom

[silverbullet07]

I have all new stuff to put in. I purchased a hays flywheel. I had the engine rebuild the same time the flywheel was surfaced. 3000 miles ago. They balanced the flywheel and the pressure plate on the assemble. I was told I should take the new and old flywheel and pressure plate and the can match the balance so I do not have any issues with it.

Do I also need to get the new hays surfaced too?

[STEELCITYFIREBIRD]

Two distinct different concentric patterns on flywheel? That is what stands out to me.

Why? Maybe from final finish of flywheel grind or possibly contamination, or combination of both. Pressure plate has three dark areas pretty equidistant from each other, may/likely just be the lighting?

I would like to see the flywheel be smoother either from dressing the stone or letting it "spark out" after the last feed.

Being nice to your passengers by feathering the clutch is not the best for it.

I'd be sure the new flywheel and pressure plate are completely oil free before you reinstall new stuff. The rough finish on the flywheel will hold oil film.

Perhaps someone was hard ( rested foot on it or slipped it excessively moving car)on the clutch that did the gear swap? (just a hunch)

Did the flywheel have the heat cracks before resurfacing? Perhaps oil was hiding in them?

[STEELCITYFIREBIRD]

The new flywheel should not need surfaced. They should not need the pressure plate, how would they know what clocking it was bolted on at?

[gtofreek]

Clutch's chatter from slippery spots on the disk, flywheel, or pressure plate. DO NOT touch any of those surfaces with your fingers before install. You need to clean them all real good with brake clean, or alcohol to get rid of any possible oily residue.

The heat checks in the old flywheel are from slipping the clutch to get it going. I used to have a 4 speed with 2.56 gears, and I had to slip it a lot to get going. My flywheel had lots of heat checks. It wouldn't be a bad idea to get the new flywheel resurfaced, as most flywheels I see have a machine turned surface on them, not a ground one. Not so good for a clutch.

Also, it would be a real good idea to have the balance checked. Stock Pontiacs have a counterweighted flywheel. Some rebuilt engines get neutral balanced. If you engine was neutral balanced, but the flywheel is not, or vice-versa, you will have a terrible vibration.

[gtofreek]

Pressure plate should be checked for balance also as some of them are quite a bit off. Then after it's balanced, the flywheel and pressure plate should be marked for location[indexed] so they can be bolted back on the same way.

[STEELCITYFIREBIRD]

Scratch my recommendation of not resurfacing the new flywheel, Paul see's these new flywheels every day and I don't.


......add pp to the list for balance.

Anything else I'm off on Paul?
Hate to be a font of disinformation!
....... Maybe I have been out of the loop to long.

[silverbullet07]

Originally Posted by STEELCITYFIREBIRD

The new flywheel should not need surfaced. They should not need the pressure plate, how would they know what clocking it was bolted on at?

When they balanced the assemble, they marked the flywheel and pressure plate for how I needed to assemble it back.

[Tom Vaught]

Originally Posted by tom s

the disc looks glazed?Tom

As far as the clutch disc goes (being glazed) that is typical of heat leeching out some of the excess bonding material. I have taken discs like yours and have glass beaded the glaze off of the disc and had the disc live a very very long life after that (even with abusive driving).

Removing the disc glaze is easy to do (if a shop has a glass beader cabinet) and your clutch disc will be fine as long as you have no broken springs, etc.

The same old WW-II mechanic, I have mentioned in other threads, told me that buying a new disc is a cheap money maker for the sellers when many times a clean-up of the disc with a glass beader will not only save the part but have it last MUCH longer in the vehicle.

Tom V.

[gtofreek]

One other thing I forgot to mention is if any of the springs in the disk are loose, deny that disk as it will chatter. Every clutch I have installed with loose springs has chattered some. I won't install one anymore with loose springs.

[Tom Vaught]

Thanks Paul, Loose springs also applied to my note but forgot to type it.

Tom V.

[silverbullet07]

Originally Posted by STEELCITYFIREBIRD

Two distinct different concentric patterns on flywheel? That is what stands out to me.

Why? Maybe from final finish of flywheel grind or possibly contamination, or combination of both. Pressure plate has three dark areas pretty equidistant from each other, may/likely just be the lighting?

I would like to see the flywheel be smoother either from dressing the stone or letting it "spark out" after the last feed.

Being nice to your passengers by feathering the clutch is not the best for it.

I'd be sure the new flywheel and pressure plate are completely oil free before you reinstall new stuff. The rough finish on the flywheel will hold oil film.

Perhaps someone was hard ( rested foot on it or slipped it excessively moving car)on the clutch that did the gear swap? (just a hunch)

Did the flywheel have the heat cracks before resurfacing? Perhaps oil was hiding in them?

Yes I recall having heat cracks before the resurfacing. One reason I'm just replacing it this time hoping it will be better. The first 1500 miles the 2.73 was in there. We live in the mountains and was having to slip the clutch bad. I may not have had it adjusted correctly then too. The next 1500 miles I had the rear ended built with a 3.36 and had the clutch adjusted correctly. That was when I experienced chatter pulling out from a stop after it got hot. About 20-30 mininutes in redlight when it would start. Hopping by changing everything I'll get a stronger clutch.

Still the 3.36 is seems hard on the clutch when I get stopped on our step hills. Thinking about swapping to a 2.98 first gear in the transmission.

[i4abuygto]

Is a cast iron flywheel with hot spots junk? The hot spots create little cracks, doesn't that run the risk of the flywheel coming apart?

[Tom Vaught]

I personally will never run a cast flywheel with heat stress cracks or otherwise.
Have posted on this before. Camero blew out the whole passenger side of his door pillar, front right quarter, right side of hood, and the right door when his deal came apart on the Martin Michigan drag way. Flywheel came out in large chunks.

Tom V.

[silverbullet07]

Made good progress tonight.

I got the new hays flywheel and pressure plate balanced to match the old set. I mounted the flywheel and shimmed the starter to fit.
Staked the pilot bearing
Thread locked the bolts and seated. Then Torqued to 40 - 80 - 100 ft lb.
cleaned flywheel very good and then 10 more times.
Cleaned pressure plate very good then 10 more times
Installed clutch disk and pressure plate using the disk / pilot bearing alignment tool
Mounted it aligning the marks from the balance
Evenly tightened the pressure plate bolts in a star pattern until seated. Torqued to 15 ft lb then to 30 ft lb

Now waiting on my transmission to be fixed