Clutch Chatter Issues

[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

[38 coupe]

I, and my friends, have had bad luck with new clutches for old Fords in the last decade or so. I now search for old rebuilt stuff and seem to have decent luck.
I am interested in the outcome, I expect it will work better than before, but how much better?

[17brpeterson1]

Well, got the "fingers" all the same height best I could and checked the bellhousing alignment too. That looked good as well. Put it back together last night and it still has some chatter but its a lot better than before. I might just look into an upgraded diaphragm clutch in the future as I think that would probably be the solution. For now Im just gonna drive it a bit and see what happens.

[TomC750]

I am impressed with your approach. I have the same problem with my '41 Mercury. I don't think it has ever been apart, but I will take the engine out at some point as the rear main seal leaks a bit. The engine mounts look hard so they will be replaced as well. VanPelt has info on clutch chatter on a link in their website according to Mac, but the link does not work.

[Ken/Alabama]

Originally Posted by TomC750

I am impressed with your approach. I have the same problem with my '41 Mercury. I don't think it has ever been apart, but I will take the engine out at some point as the rear main seal leaks a bit. The engine mounts look hard so they will be replaced as well. VanPelt has info on clutch chatter on a link in their website according to Mac, but the link does not work.

There is no seal in the rear of the 41 engine. It has a slinger .

[TomC750]

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Originally Posted by Ken/Alabama

There is no seal in the rear of the 41 engine. It has a slinger .

Thank you Ken! I assumed there would be like newer engines. I have a "Green bible", so I'll reference that as well.

[TomC750]

Originally Posted by TomC750

Thank you Ken! I assumed there would be like newer engines. I have a "Green bible", so I'll reference that as well.

My clutch chatter has been curing itself. The more I drive it the better it gets. The car was in storage for many years. Rust maybe?

[Bullerman]

I have the same problem as you. Terrible shake on take off in first. Shifts ok from first to second and second to third. Get another shudder when downshifting from third to second.
I like you got a new pressure plate and clutch disk from Shoe Box.
I had everything installed as I don't have the place to do it. Thing is it was doing the same thing before I had anything done. I will be following your post to see what you find out.

[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.

[Death Row Dave]

The spring between the linings , I’m betting is your problem also . Never had much luck using aftermarket discs in Fords with Long style pressure plate . I have always noticed the OEM Marcel Spring is larger in OEM discs . New stuff seems to mostly off shore stuff , common to look perfect but always a slight bit off . A clutch chatter is one thing that drives me insane .