Diaphragm clutch and overcenter spring

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dusterbd13

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Ok, so i should probably know about this by now, but i dont.

Ive seen in a few other threads about removing the overcenter spring when using a diaphragm clutch.
I have never taken mine out (that i know of. Ive had the car damn near 25 years, so its kinda hard to remember)
Ive been running diaphragm clutches for a while. (30k or so).
Im replacing a blown clutch now. First for this car.

What is the purpose in removing the overcenter spring? What happens when you dont? And anyone have a good picture of the spring? I love the clutch effort i have had in the car, as its very easy on my bum knee and i don't want to lose it. But if the overcenter spring is what caused the failure.....
 
Picture grabbed from Brewer's Performance: Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists
CPA70A-1.jpg
 
I could be wrong but I don't know if you have to remove for all diaphram clutches. I do know that Centerforce specifies to remove the spring for their clutches as they have a centrifugal assist that may be messed up with the spring.
 
I remember seeing threads here on how to remove it. It's pretty strong so be careful. Basically, have someone push the pedal down and force washers between the coils. When the pedal is released it won't be under so much tension and you can remove it. Best to check the threads first.
 
Yup. Spring is still there.
I'll have to call the clutch manufacturer to see what they reccomend, right?
Spec clutch setup.
 
dusterbd13 said:
Ok, so i should probably know about this by now, but i dont.

Ive seen in a few other threads about removing the overcenter spring when using a diaphragm clutch.
I have never taken mine out (that i know of. Ive had the car damn near 25 years, so its kinda hard to remember)
Ive been running diaphragm clutches for a while. (30k or so).
Im replacing a blown clutch now. First for this car.

What is the purpose in removing the overcenter spring? What happens when you dont? And anyone have a good picture of the spring? I love the clutch effort i have had in the car, as its very easy on my bum knee and i don't want to lose it. But if the overcenter spring is what caused the failure.....
Click to expand...



The over center spring was designed to aid in pushing the pedal down, back in the day when the nor was jack as much plate load as you can into the pressure plate and then beat the **** out of the car with it.

It was largely designed to make it easier for women to push the clutch.

When the pressure plate load is down where it should be, you need to remove it because the pedal will stay on the floor as the pressure plate doesn't have enough spring pressure to push the pedal back.

I should have recorded the discussion I had with my cousin when he discovered head to remove his over center spring. I let him get it all together and find out the clutch wouldn't push the pedal back. Had I told him to remove it while the car was apart and the pedals were on the bench, he would have never listened. So he got it all together and the pedal stayed on the floor I just laughed my *** off. He still doesn't quite believe it, even though he has done it.


It just doesn't make sense in his brain. No ****, my cousin though the spring on the linkage down at the fork was what pulled the pedal back, and it the springs in the pressure plate.


I should have recorded all that ****. Classic stuff.
 
You only remove the spring when you put the newer style clutch which is the diaphragm vs the old lever clutch style. I had a diaphragm clutch with the over head spring still on and the pedal would not come back up once i removed the overhead spring it was like butttter. Diaphragm clutches give the modern car feel, i personal like the old school lever style keeps my left leg in shape. Its easy to take off if you use right pry bar, not a tire iron etc. I took it off in less than 5 mins, but the first time it took forever cause i used a tire iron.
 
Slantsix64 said:
You only remove the spring when you put the newer style clutch which is the diaphragm vs the old lever clutch style. I had a diaphragm clutch with the over head spring still on and the pedal would not come back up once i removed the overhead spring it was like butttter. Diaphragm clutches give the modern car feel, i personal like the old school lever style keeps my left leg in shape. Its easy to take off if you use right pry bar, not a tire iron etc. I took it off in less than 5 mins, but the first time it took forever cause i used a tire iron.
Click to expand...


It really has nothing to do with the style of lever. It has more to do with pressure plate spring load.
 
IMO, Last thing ya' want is the OC spring pressure affecting the diaphragm fingers and causing constant contact with the release bearing.
The OC spring actually assists in in both directions. Pedal effort is decreased on one side of over center and it will return the pedal to the up stop on the other side of center.
With the OC spring installed, and if the pedal return over center is not achieved with the combination of clutch rod adjustment, diaphragm springs, and clutch rod spring, you'll have a constant force on the diaphragm fingers and premature wear and possibly clutch slippage.
Removal of the OC spring eliminates this force, however, now the pedal can/my flop around you and sit lower than the brake pedal. Folks here have posted fixes for this also.
I believe most folks going with diaphragms pull the OC spring as a general rule since pedal effort is minimal compared to the B&B style.
 
yellow rose said:
The over center spring was designed to aid in pushing the pedal down, back in the day when the nor was jack as much plate load as you can into the pressure plate and then beat the **** out of the car with it.

It was largely designed to make it easier for women to push the clutch.

When the pressure plate load is down where it should be, you need to remove it because the pedal will stay on the floor as the pressure plate doesn't have enough spring pressure to push the pedal back.

I should have recorded the discussion I had with my cousin when he discovered head to remove his over center spring. I let him get it all together and find out the clutch wouldn't push the pedal back. Had I told him to remove it while the car was apart and the pedals were on the bench, he would have never listened. So he got it all together and the pedal stayed on the floor I just laughed my *** off. He still doesn't quite believe it, even though he has done it.


It just doesn't make sense in his brain. No ****, my cousin though the spring on the linkage down at the fork was what pulled the pedal back, and it the springs in the pressure plate.


I should have recorded all that ****. Classic stuff.
Click to expand...
Assume this is The Brainiac you want to line me up against?!
 
I thought the over center spring was used to keep the clutch pedal to the floor after the car was converted to an automatic.
That's of course after the dumb schmuck couldn't figure out how to adjust the linkage and shift the car like a man and finally gave up on it.
 
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