Technical Pressure plate differences

SO, I either have a freak pressure plate, or there is more than just one version of the Long style three finger PPs. Have installed Cornhusker kit, done correctly, but discovered not enough throw to disengage the clutch. Looked at some other pressure plates I have laying around, and the fingers actually poke out beyond the hole. In other words, they would work, but they are old, the new one has the fingers at about the location they would be in when throwout bearing is in....anybody ever see this? .....ready to run on the road except for this....ideas? PS, yes some have adjustment bolts, others not, mine does not have those, but that is not the issue.

 

Maybe a longer TO bearing?

 

I think there were 3 different length throw out bearings for Chevys. It could also be the clutch actuating arm being the wrong shape.

 

What does Gary say?

 

Good place to start.

 

There are 3 and maybe 4 different lengths of throwout bearings, as well as different lengths of pivot balls.
Sounds like a "tall" or longer throwout bearing would solve your issue.

 

Thanks for the replies....I hadn't thought about a different bearing....and yes, Gary at Cornhusker has been VERY good about response and helping.....but it is the one component he did not provide to this project so could only confirm that what I did was correct...and to check in with Fort Wayne clutch for a correct pressure plate. Pretty sure I simply got a "bad" pressure plate locally, will know after Monday and post.

 

Post a picture of the clutch............ I kinda doubt the clutch is ***embled wrong. They are pretty simple things. As long as it can deflect and release the disc, its working. I think the problem is in the linkage. The first thing you have to do is insure the clutch arm is far enough back from the clutch to have sufficient travel to push it. To get to that point you need either a longer throwout bearing or an adjustable pivot ball......or both. The clutch arm needs to make the TO bearing have initial contact to the clutch while its behind the center of the pivot ball........thats what you should be shooting for.

This is for Jeeps, but has pretty good explanation of linkage and bearings.
https://www.novak-adapt.com/knowledge/clutches-etc

 

There is a “sweet” spot for clutch forks. They will work at either end of their stroke but should be centered for ease of operation and side friction of the throw out bearing collar. I’ll lay under a car and mix and match parts until I can get it centered in the stroke. It also easier on the pedal linkage and your foot. I’ve found the adjustable ball helps a lot. The bad part is if you can’t get the fork in with pressure plate installed... you start over.

 

A buddy had a problem with a clutch in his 34. It would just barely release. His hydraulic release bearing didn't quite push the levers far enough. The guy who supplied the clutch and the guy who supplied the release bearing both said it should work. Simple measurements said, no way. We started looking for pressure plates with release fingers that stood higher. We didn't find exactly what we wanted and my buddy took the pressure plate to a local clutch and brake shop. He asked if the clutch could be taken apart and new release fingers installed. The counter guy called the shop guy to come take a look. He took one look and said the pressure plate wasn't ***embled correctly. He took it in the back and came out about 15 minutes later with the properly ***embled pressure plate. Put it in the car about 8 years ago with the problem solved.

 

A fatter bearing by about one inch fatter would be a solution, any source ideas?

 

Thanks for feedback, we have checked this pressure plate against two others, they all seem identical in every detail. Still scratching my head on this.

 

Thanks, I agree, but the way this comes from Cornhusker the fork and bearing are at the rearmost set, and even after total throw forward, it barely hits the fingers. Not enough to disengage clutch.

 

this is an 8BA flathead, and starting to think something is simply mis-drilled in the kit, or wrong skinny throwout bearing, or something with the arms etc.....the bearing needs to travel about two inches just to contact the fingers, so the issue seems to be linkage somehow.

 

I’ve never had them side by side to compare with a ruler/tape. GM had 3 different sizes, I remember putting in a new clutch, using the original TO bearing and I could get it to release. I went back to the AP store, guy knew just what I needed with the clutch I’d bought. Someone might be able to post up size difference, but Google might help as well.

 

For the record, Mr. Dummy here forgot, the fingers move OUT about an inch when bolts are removed, duh, so it is NOT the pressure plate as I had hoped. Have three, they all are identical. Gotta be in linkage somewhere, a fatter like two inch throwout bearing would solve, but everybody keeps saying this is bolt together kit so I need to work with supplier to see if its a mis drilled shaft, arm or whatever.

 

Don't have the disk in backwards do ya?

 

Just some of my stash.... I can make it fit and I won’t aquit.

 

We all have those "duh" moments now and then. One good thing about getting old is we forget about them a lot more quickly and fall back into thinking we are "perfect" again

 

One thing I ran into in past years with "rebuilt" discs was the actual disc thickness, A ford long style ***embly should have a disc of approx. .250" and a GM uses approx. .312". A thicker disc moves the fingers in towards flywheel.

 

No, but thanks for the input....really baffled, none of my pressure plates will reach far enough toward the bearing to engage enough to activate, about ready to figure a way to add extensions to the fingers and move on.

 

You can't add extensions to the fingers. Why don't you get a longer bearing and try it? You keep saying the clutch is bad, but multiple clutches all have the same problem. That makes no sense, so the problem has to be in the linkage or the housing you are using. Again, pictures help more than words.

 

Delayed for couple days this note, but.....spent two days plus pulling things apart, talking to Gary and to Ft Wayne, measuring and remeasuring, put it all back together, and it works perfectly. Just want to be on record that Cornhusker has superb support, the kit works, and the problem never existed....maybe rod adjustment, it's a mystery, but thanks to all the notes of possibles, and yes I feel like a dummy.

 

Don't feel like a dummy, anyone worth their salt has chased their tail trying to resolve a problem similar to what you did. Its called "experience" and it says a lot about you that you didn't give up but fought it till you got it right. We've all been there.........

 

SO, it's annoying when we all try to help a guy out, and he never says what the solution to his problem was.....after some more fiddling and fooling, it turns out most of my clutch issue was due to not managing the master cylinder.....it did not get enough throw to fully activate the slave partly due to geometry, partly due to adjustment of the rod...bottom line, if you set up an S-10 with Cornhusker pieces, pay attention to the master cyl.

 

I must have missed the part about this using hydraulic " linkage " ?

 

^^^^^^^^^^^I think most of us understand what he is referencing, what's your problem in reading comprehension?

 

Me too I thought it was mechanical. Guess I’ll go up and delete my posts... and not ***-u-me so much.

 

Yup, me too. I didn't read anywhere in his posts that he was using hydraulic cylinders.

 

Well ****, my double bad.....guys like me are a pain, and here I went and did it, left out maybe the most important single item.....I am one of the guys I complain about. Sorry.