Technical WHAT THE HELL?

I have this clutch in my 1962 corvette. I was told it was suppose to be a rear quick and hard grabbing clutch. It is the hardest clutch I have ever pushed on. The pedal is so hard, that it feels like I am pushing the thrust bearing through the block. Yes it disengages and hooks up, BUT why so hard to push. I have never heard of a clutch being this hard to push. what the hell.

 

It may be your t/o bearing is pushing too far away from the tips of the fingers. Less leverage.

 

From the marks on the fingers, Panheadguy may be correct. Looks like the diameter of the TO bearing is too big and pushing in the middle of the pressure plate fingers, instead of toward the outer ends. If a smaller diameter TO bearing was used it would drastically change the leverage on the PP fingers and reduce the pedal pressure.

 

Both guys are right, you might have a t.bearing for a B&B clutch rather than the diaphragm unit you have now.

 

Need smaller t/o bearing. By the looks of the marks

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And make sure the TO bearing has a radiused face, not a flat face.

 

It's in ur return spring, just change it out to a lighter one just make sure it doesn't stick to the floor lol just ask me how I kno? Lolol plus u may half to change the TO bearing it looks to be a little to big butt I would start at the spring it's cheaper and easier but if that don't do it then move to the to bearing or do the bearing since u own a vette u can probably afford it lol j/k lol


Sent from my iPad using The H.A.M.B. mobile app HotRod Harry

 

Just my 2c, but is this a racecar? Looks like a heavy duty clutch that would be best suited for the race track. And a multi disc unit that would require more pedal pressure.

 

Agree with previous comments. Also look at your clutch pedal ratio. Maybe start doing some squats.

 

I'm with you guys,the whole thing looks like it's made for a race car. HRP

 

Multi disc race clutch and probably better suited for hydraulic throw out bearing. I got to say to must have a lot of motor in that plastic wonder car.

 

After looking at your profile I see it is a race car.HRP


PROFILE ~ 1962 corvette. Comp eliminator/ MODIFIED PRODUCTION

 

Is trans perhaps the sort of Ford 4 speed toploader used on big blocks, with the big input shaft? That would account for big throwout...which needs a pressure plate with different fingers.

 

Gonna get one big left quad

 

A multi-disc clutch actually can get by with *less* pressure. Because the friction surface is so much greater area with the multiple discs. On regular single clutch, and high power, the way to get more power transferred without slip is to use a high force pressure plate. But a multi-disc clutch does not require that.

Agree that it seems your throwout bearing is pressing on the diaphragm fingers too far out from the center. That makes the pedal force higher than it has to be.

 

Ask who gave you the info on the clutch in the first place? Ask which TOB and how much movement is required at the bearing and you can adjust your linkage to get the needed amount..Multi-disc clutches don't have to have lots of pressure plate pressure because of the multiple discs; more surface area..

 

I doubt this could be the problem but one never knows. Years ago a buddy had a badly worn pilot bushing in his small block and the clutch peddle was almost impossible to depress. New pilot bushing and all was wonderful. Like I said doubt this is the problem but worth checking just in case.

 

But the dia is reduced and so goes the leverage thus the addition of more disc's. I would think that setup more inclined for road-race to get the engine to RPM quickly out of the turns. By chance have you expressed your issues with the maker??? Thats step #1

 

Thank you guys so far for helping. Keep suggestions coming. Yes it is a CM/P CORVETTE. The T/O bearing looks high on the fingers. Somebody said need to do more squats. I weigh 240lbs and 6ft3. And I can't hold that clutch down for the staging lights. I do have a Doug Nash 5 speed transmission. I checked the geometry of the clutch pedal and rods to pedal and it is perfect. I even went as far as to install and stock clutch in car and it pushed down like butter. So with all of you help I may try t/o bearing or go to a different clutch all together. The car is very light and very fast once it gets off the line. Thank you.

 

The flanged main bearing and the crankshaft probably have not been enjoying this much either.

 

Good point. I never start a stick shift car with the clutch in ,for that reason. Clutch out, neutral.
Wouldn't hurt to check thrust bearing end play while it's apart.
Who made the clutch? Does it have SEMA markings?
I think I'd start there.

 

Look at your pedal geometry too, when we ran multidisc we'd operate the clutch pedal by hand. can you feel it 'tip over?' when in the lights the pedal is almost effortless, if you can't feel it 'tip over' then it is a question of geometry. Got to have the right TO like others have said. Seems tome the clutch pedal from Rick Jones has a number of holes, have a look at one of them.

 

make the return spring pull in the other direction

 

The clutch is suppose to be a Lingenfelter clutch. I don't think it is. I thought of a return spring. I thing it is an old MR GASKET clutch. Built back in the 70s. BUT, this clutch is so hard you have to put 2 feet on pedal to push it. Something wrong. I will try T/O bearing. The pedal moves so easy with out clutch installed it fall to the floor. If the stock clutch is easy than I will put new clutch in. But maybe a power glide. LOL.

 

We run a triple 7" Ram and it has almost no pedal pressure and uses a Lightweight starter ring gear and a Howe hydraulic TO.

 

jimmy six. thank you.

 

Find some drag racers and they can probably tell you what brand it is so you can get the correct throw out bearing for it. You might have to make one by grinding the outer edge so it only touches the inner end of the fingers.

 

Here is the Howe throw out bearing. It has the rounded surface that would only touch the tips. Somebody must have made a mechanical one.

 

Engine man. that bearing looks like it will fit finger better at the end of fingers. thank you.

 

And the reason for that would be?