Clutch disengagement problem
Thread Starter
Racer
Joined: Aug 2005
Posts: 456
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From: Forty Fort PA
Clutch disengagement problem
I just converted my 75 from auto to manual (M22). I installed an 11" clutch, all new linkage parts, pedal, etc. The problem is, I can't get the clutch to disengage. If I start it in neutral, I can't get it into any gear. I have adjusted all the slack and then some out of the adjustment. Any thoughts? 
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
most likely the throwout bearing is stuck on the input shaft cover...could be missalignment that's causing the bearing to stick or the pressure plate is defective. Also the fork may be damaged.
You have to remove the tranny and check everything out. I assume you used am input shaft to align the spines, and as you torqued the pressure plate, you moved the input shaft in and out...if not, that could be the problem....by moving the shaft , you are assuring there is free movement and guaranteeing perfect alignment. You don't want a drag or have difficulty moving the input shaft.
You have to remove the tranny and check everything out. I assume you used am input shaft to align the spines, and as you torqued the pressure plate, you moved the input shaft in and out...if not, that could be the problem....by moving the shaft , you are assuring there is free movement and guaranteeing perfect alignment. You don't want a drag or have difficulty moving the input shaft.
Last edited by GDaina; Sep 8, 2005 at 07:50 AM.
Thread Starter
Racer
Joined: Aug 2005
Posts: 456
Likes: 0
From: Forty Fort PA
The linkage moves so how could the T/O bearing be stuck? I used the plastic alignment tool to align the disk and pressure plate during install. The tool moved freely in and out before and after torquing.
What are the odds of having the bellcrank in wrong so that the travel of the lower rod is too short?
What are the odds of having the bellcrank in wrong so that the travel of the lower rod is too short?
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
I have seen many clutch discs stick to the pressureplate/flywheel if left sitting for any lengh of time. It usually happens if the humidity is high. Rust maybe. Try starting it, use the engine torque to break it loose (clutch depressed fully)...be careful, the vehicle will want to move...
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Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
It could be the wrong TO bearing, too short a pivot stud, incorrect linkage geometry, or slop in linkage.
This is really a two-person job...one pushing in on the clutch, the other observing the movements. If I had to guess, I'd say that it's going to be in either the bearing or the pivot stud.
This is really a two-person job...one pushing in on the clutch, the other observing the movements. If I had to guess, I'd say that it's going to be in either the bearing or the pivot stud.
Thread Starter
Racer
Joined: Aug 2005
Posts: 456
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From: Forty Fort PA
I'll try to see if it is stuck.
The parts are all new (pedal (refurbished actually), bushings, push rods, bellcrank, fork, pivot ball, etc.). Linkage is a new Hurst set-up.
If there is a problem with the parts being wrong, my guess would be Fork or pivot ball (or possibly throwout bearing but that is new and ordered to the car from Zip along with the pressure plate) When I bought the bell housing, I was told that one size fits all (small block at least). I initially got the wrong fork (didn't have the verticle hole for the pin) but I replaced that before putting in the tranny.
The parts are all new (pedal (refurbished actually), bushings, push rods, bellcrank, fork, pivot ball, etc.). Linkage is a new Hurst set-up.
If there is a problem with the parts being wrong, my guess would be Fork or pivot ball (or possibly throwout bearing but that is new and ordered to the car from Zip along with the pressure plate) When I bought the bell housing, I was told that one size fits all (small block at least). I initially got the wrong fork (didn't have the verticle hole for the pin) but I replaced that before putting in the tranny.
Thread Starter
Racer
Joined: Aug 2005
Posts: 456
Likes: 0
From: Forty Fort PA
Does anyone know the position of the engine end of the bellcrank in the engaged condition? Is the lever vertical, or is the bottom end tilted towards the front of the car? If so, how much, an inch, or more?
Thread Starter
Racer
Joined: Aug 2005
Posts: 456
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From: Forty Fort PA
Unsolved clutch problem
Hi everyone.
I replaced the throwout bearing with the correct one (same as old except for a small difference in axial length). I extended the fork pivot ball about 0.025 inches and went through all the parts. Everything seems correct and positioned properly. The clutch still will not disengage!
Are there more than one fork with the hole in the outer end for the pin (I know about the early one)? Is there one that has less 'offset' than the correct one?
If I attached the bracket for the cross shaft in the wrong spot, could this be a factor? I mounted it so that the cross shaft is perpendicular to the engine looking down from above.
I replaced the throwout bearing with the correct one (same as old except for a small difference in axial length). I extended the fork pivot ball about 0.025 inches and went through all the parts. Everything seems correct and positioned properly. The clutch still will not disengage!
Are there more than one fork with the hole in the outer end for the pin (I know about the early one)? Is there one that has less 'offset' than the correct one?
If I attached the bracket for the cross shaft in the wrong spot, could this be a factor? I mounted it so that the cross shaft is perpendicular to the engine looking down from above.
Thread Starter
Racer
Joined: Aug 2005
Posts: 456
Likes: 0
From: Forty Fort PA
I hadn't considered that the clutch disk might be in backwards. Will it fit backwards? It is installed so that the side with the springs is facing the pressure plate.
I have varied the pedal free travel from zero to 1 1/4 inches. Doesn't seem to make a difference on disengagement.
I have varied the pedal free travel from zero to 1 1/4 inches. Doesn't seem to make a difference on disengagement.
Melting Slicks
Joined: Mar 2005
Posts: 2,094
Likes: 298
From: Midlothian VA
Originally Posted by langg
I hadn't considered that the clutch disk might be in backwards. Will it fit backwards? It is installed so that the side with the springs is facing the pressure plate.
I have varied the pedal free travel from zero to 1 1/4 inches. Doesn't seem to make a difference on disengagement.
I have varied the pedal free travel from zero to 1 1/4 inches. Doesn't seem to make a difference on disengagement.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Originally Posted by langg
I hadn't considered that the clutch disk might be in backwards. Will it fit backwards? It is installed so that the side with the springs is facing the pressure plate.
I have varied the pedal free travel from zero to 1 1/4 inches. Doesn't seem to make a difference on disengagement.
I have varied the pedal free travel from zero to 1 1/4 inches. Doesn't seem to make a difference on disengagement.
