Clutch Chatter Issues

[Ken/Alabama]

Originally Posted by 17brpeterson1

Recently bought a 1949 Sedan with the flathead v8. When I bought it I thought it just had a bad clutch. Real bad, car shaking, chatter releasing it into first or reverse. I replaced it with a clutch from Shoebox Central. Pressure plate was a little different being the fingers the throw-out bearing sits on did not have adjustable screws like the old one. I installed the new clutch (and resurfaced the flywheel) and the bad chatter remained. Replaced engine mounts and transmission mount, took a video of the clutch linkage while releasing it under load and the linkage looked solid.

So yesterday I took the transmission and clutch back out. Upon looking at the pressure plate fingers I saw that on of the three fingers did not nearly have the same wear markings as the other two where the throw-out bearing sits on them.

Took the flywheel off and on the bench I bolted the whole clutch together with the disc in. What I found was that one finger that was about .030" higher than the other two fingers. Also there was a hot spot in the same place on both the pressure plate and flywheel right across from the high finger.

Now I have read about the bellhousing to flywheel alignment too and will check that as well, but if the transmission and friction disc were out of alignment, the hot spot would not be in one place singular place I think.

Anyways, I was able to mess around with the pressure plate fingers and shims underneath where the finger pivot bolts to the back of the pressure plate and I got the fingers all even to around .001 to .002"of each other.

What's funny is when I got this clutch I noticed one of the little copper shims just hanging out loosely in the springs. I looked and noticed that one of the fingers did not have a shim under in so I stuck that loose shim in there thinking it needed to be there. Maybe I messed up the alignment from the factory by doing that and that loose shim was just a mistake.

Either way, gonna try this out and report my findings, if anyone has encountered such issues or has thoughts about this, please chime in. Not sure if .030" out on a finger can cause such bad chatter but I'm running out of possible issues and it seems like it could be a legitimate culprit.

Thanks

A few years back I was having clutch chatter problems and replaced it two or three times with the same results. All the ones I were getting were new manufacture from who knows where. I had a good discussion with a reputable clutch rebuilder and he told me the disc was more than likely the cause. He explained how important it is to get the correct Marcel spring sandwiched between the clutch linings. He said just about all the offshore clutches either have a Marcel spring that’s to weak or absent altogether. And as you’ve already discovered how important finger height has a part in this also. I avoid new manufacture clutches unless I’m sure of it origin.