# Shuttering when letting out the clutch



## 1964oldgoat (Aug 7, 2020)

I recently bought a ‘64 GTO with the M20 four speed, and when I let the clutch out - at whatever rpm - I get serious shuttering. The whole car shakes. Once she’s in gear and cruising it’s fine. What could be the cause? The guy who sold it to me said he just put in a new clutch. Could he have done something wrong? The big question is this - can the shuttering ruin the engine or tranny? If so, I’ll get it towed to a transmission shop.
Any thoughts on any of this would be helpful. Thanks!


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## PontiacJim (Dec 29, 2012)

Shuttering is not a good thing, just means something is not correct. It won't shutter going down the road because the clutch is engaged.

If it was a 4-speed conversion, it could simply be that the rear gear ratio is too stiff, ie highway gears found in an automatic rear end like 2.56, 2.76, 0r 3.08 gearing. You want around a 3.23 or better. Anything lower would require a lot of slipping of the clutch to get the car rolling and cause bad shuttering.

I would want to have it looked at. I don't trust people. New clutch? Just a clutch or a complete set-up?

It could be a sign that the flywheel was not surfaced when the new clutch was installed. Wrong clutch set-up. Something may have been left out or not replaced.

I would think you should be able to drive it to a shop, but you will have to make that decision. If you feel more comfortable having it towed, then I would do that.


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## BLK69JUDGE (Jun 10, 2010)

as jim mentioned .... thats not correct since it happens in all gears

needs to be looked at .... Im afraid he did not surface the fly wheel,,, or it got oil or something on the disc...
clutch chatter will destroy a muncie,,, done it ...


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## 1964oldgoat (Aug 7, 2020)

Thanks a lot for the reply. I’ll get it towed to a reputable shop here and see what they can figure out. Thanks again!


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## 1964oldgoat (Aug 7, 2020)

BLK69JUDGE said:


> as jim mentioned .... thats not correct since it happens in all gears
> 
> needs to be looked at .... Im afraid he did not surface the fly wheel,,, or it got oil or something on the disc...
> clutch chatter will destroy a muncie,,, done it ...


Oh now I’m really scared - rowing to the shop for sure!


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## Mine'sa66 (Oct 30, 2019)

1964oldgoat said:


> Oh now I’m really scared - rowing to the shop for sure!


Don't be scared, but unless you have the skill/knowledge to diagnose this yourself, don't drive it around like that. Tow it to a good trans/general shop and have it looked at. Several things could be going on, most of which are hard to solve and the driveway and many will do serious damage if left.


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## 1964oldgoat (Aug 7, 2020)

Mine'sa66 said:


> Don't be scared, but unless you have the skill/knowledge to diagnose this yourself, don't drive it around like that. Tow it to a good trans/general shop and have it looked at. Several things could be going on, most of which are hard to solve and the driveway and many will do serious damage if left.


I don’t - I know motors pretty well but never touched a transmission. Nor do I have the tools here to work on it (living in a condo after a divorce).
Thanks for the advice - I’ll get her towed to the best transmission shop I know of around here.


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