Vibration in clutch pedal
Thread Starter
Burning Brakes
Joined: Oct 2000
Posts: 878
Likes: 60
From: Minneapolis, MN USA
Vibration in clutch pedal
Hi all - just got my 1970 L46 motor and xmission rebuilt and put back together. Most everything is good...however, I am noticing a vibration in the clutch pedal just as the clutch begins to engage...that is, as I push the pedal down, I go through the "free play" portion of the travel and I don't feel much of anything...then, as there is more tension/resistance on the pedal (just after the free play), I can feel vibration in the pedal. When I have the pedal all the way to the floor, I don't feel any vibration.
Any suggestions of what this could be? Missing a spring somewhere? Something in the Z-bar linkage?
Any suggestions of what this could be? Missing a spring somewhere? Something in the Z-bar linkage?
Race Director
Joined: Nov 2006
Posts: 13,296
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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Cruise-In VIII Veteran
Throwout bearing not clipped into the fork correctly? Something is not right and I highly doubt it would be in the linkage. I would be pulling the trans again. Sorry.
Racer
Joined: Feb 2018
Posts: 275
Likes: 31
The only other possibility - would be the nut that attaches the Zbar to the frame is loose. When you put the throw out bearing in the fork do you recall if you made sure you did it correctly - it is very easy to do it incorrectly. Also, you can see the fork where it rests on the privot ball if you pull the rubber back around the fork - make sure that is sitting correctly. It does sound like a throw out bearing or a pilot bearing. did you grease the pilot bearing when you installed it? Do you have fluid in the tranny? Just some ideas - Bob Messina
Le Mans Master
Joined: Mar 2004
Posts: 7,507
Likes: 1,513
From: Little Rock AR
The fingers on the pressure plate diaphram are warped. They are not all the same height when torqued down and assembled. You could see it if you assembled it on the bench before it was installed.
As the engine rotates, the bearing wobbles as it contacts the fingers. Once you get some pressure on the fingers they move inward and the bearing wobbles less. Only way to fix it is to replace the defective pressure plate.
As the engine rotates, the bearing wobbles as it contacts the fingers. Once you get some pressure on the fingers they move inward and the bearing wobbles less. Only way to fix it is to replace the defective pressure plate.
Intermediate
Joined: Apr 2019
Posts: 45
Likes: 5
From: poughkeepsie ny
I adjusted the clutch on my '71 . The clutch felt "tight' . After several gear changes ...... boom the pedal went to the floor. If you check the AIM , the rod form the pedal to the bellcrank attached to the block is BENT ! The spring clip at the clutch pedal saw too much pressure and snapped . Adjust the clutch while the adjuster is semi tight . Depress the clutch pedal several times so the rod finds is happy place ......, than tighten .
Pro
Joined: Aug 2000
Posts: 611
Likes: 168
From: Vancouver B.C.
Had a vibration on my pedal that drove me nuts years ago. Pulled tranny even. Everything ok. Turned out to be the plastic bushings in the z bar. Moral of the story. Eliminate the cheap easy things first. Also clutch rod to fork should have anti rattle springs. Good luck.
Burning Brakes
Joined: Jun 2010
Posts: 1,165
Likes: 93
From: Bellmore NY
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Race Director
Joined: Mar 2016
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From: Napa Valley California
What clutch are you running?
There have been numerous posts in threads about members who had CenterForce clutches who were experiencing vibration issues.
Once they swapped out to a different clutch manufacturer their vibrations were gone.
There have been numerous posts in threads about members who had CenterForce clutches who were experiencing vibration issues.
Once they swapped out to a different clutch manufacturer their vibrations were gone.