clutch question

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ddettloff

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I just replaced the clutch pressure plate and throw out bearing on my 67 cuda 318.
The pedal feels good but when pushed it stays on floor and won't spring back.
double checked the throw out bearing install springs placed same spot all is the same as it was but the threaded rod is all the way to the end and still wont pop off floor any ideas.
 
Did you use a centerforce clutch by chance? Seems to me I've read that they need the large over enter spring removed from the pedal addy to work properly. Otherwise, what you're describing happens. I'm sure someone much more knowledgeable will chime in with better info soon. This was just the first thought that popped into my head.
 
Did not use center force clutch the only thing different was old pressure plate had 3 prongs new one has full circle of fingers
 
Hmm, sounds like a diaphragm style clutch similar to centerforce. My suggestion might still apply.
 
Hmm, sounds like a diaphragm style clutch similar to centerforce. My suggestion might still apply.

Exactly. You nailed it.

Even though I've never done it, the diaphragm style causes issues with that spring.....
 

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That is the type I used why would the pedal spring have to be removed. And can it be removed without taking pedal assembly out .
 
I think I've read that you can push the pedal down to stretch the spring and install washers between the coils. When you pull the pedal back up the spring will be loose and can be disconnected. Remove it carefully though.
 
That is the type I used why would the pedal spring have to be removed.

Because they are totally different designs. "Back in the day" it was common for some "stocker" (mostly GM) diaphragm clutches to "stay on the floor" at high RPM. I believe some modern performance diaphragm covers have centrifugal weighting, but I'd guess most do not

Your original "3 finger" is called a Borg and Beck. High performance covers have rollers between the cover and pressure plate which throw outwards at high RPM and help press the pressure plate down, increasing pressure. This is one reason you need the helper spring under the dash

Ford, or "Long" designs do the same thing, except they have weights originally cast into the fingers. Aftermarket performance "Long" clutches sometimes have holes there where you can tailer the weights as needed.

Some BB aftermarket performance covers have been modified to use Long style weighted levers, so the "picture" gets muddy


Competition Long with weight holes

clutch_university_088.jpg


These weights are cast as part of the fingers

91015635_R.jpg
 
I think I've read that you can push the pedal down to stretch the spring and install washers between the coils. When you pull the pedal back up the spring will be loose and can be disconnected. Remove it carefully though.


I did remove my spring this way..... PITA!! But possible.
 
The washer idea is great that spring is solid.
My question is why remove it I don't understand how removing that spring will get the pedal to return to correct position.
I was able to use a longer adjustment rod and it helped some but when pedal is pressed to floor you can gear a grinding sound at a loss here.
 
The washer idea is great that spring is solid.
My question is why remove it I don't understand how removing that spring will get the pedal to return to correct position.
I was able to use a longer adjustment rod and it helped some but when pedal is pressed to floor you can gear a grinding sound at a loss here.

You didn't read above? It's because if the DECREASED pedal effort IE completely different design between the 2 finger and diaphragm clutch covers. None of these cars ever came from the factory with a diaphragm cover so there was never a provision "for" the linkage.

When you increased rod length you caused the pedal, when at the floor, to depress the fingers far enough to hit the clutch disk. This by the way can damage a diaphragm clutch.
 
The washer idea is great that spring is solid.
My question is why remove it I don't understand how removing that spring will get the pedal to return to correct position.
I was able to use a longer adjustment rod and it helped some but when pedal is pressed to floor you can gear a grinding sound at a loss here.


That spring helps pull the pedal to the floor. When you have a pressure plate that is heavy, it will help. The newer design clutch ( the one with all the fingers) don't need the extra help to depress it.

I ask myself this same question but I have since removed the spring and the pedal is a little stiffer but not unbearable. It is necessary to remove it with that style clutch.
 
Thanks for all the help and info would have never thought of the pressure plate difference.
Was able to remove spring and works great now, have been playing with these cars for 30 years and still learn new things.
A big thanks for the info.
And that spring is a mother to get off the pedal.
 
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