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Muncie m20, stock bellhousing, but hayes flywheel.
If I set up my pivot ball to spec 4.75” from Top of pivot ball to bellhousing surfare I have no free play between pressureplate and throwout bearing(the clutchfork is not loose at all). Ive got a adjustable pivot ball, is the only thing I can do to adjust the pivot ball untill I have some freeplay in the clutchfork (pressureplate and throwout bearing)
How much freeplay should it be?
after I have som freeplay on the clutchfork, then I connect the rest of the linkage, and adjust so the linkage in enginebay so pedal has about 1 inch freeplay, right?
Before you settle on the 4.75 dimension, you need to check on the flywheel thickness of yours compared to the one used to determine the 4.75 inch dimension. I bet your flywheel is slightly thicker than stock.
Yes, adjust your pivot ball. You don’t need much clearance between bearing and pressure plate but definitely a little, just so bearing doesn’t spin by riding on the fingers. Also make sure you are using the short (1.25 inch) throw out bearing.
Last edited by 69ttop502; May 22, 2020 at 12:57 PM.
Before you settle on the 4.75 dimension, you need to check on the flywheel thickness of yours compared to the one used to determine the 4.75 inch dimension. I bet your flywheel is slightly thicker than stock.
Yes, adjust your pivot ball. You don’t need much clearance between bearing and pressure plate but definitely a little, just so bearing doesn’t spin by riding on the fingers. Also make sure you are using the short (1.25 inch) throw out bearing.
Yes my new Hayes flywheel was thicker than stock, and I calculated with that. But the clutchfork did press at the pressureplate....so I adjusted the pivot so I have about 1/8 free play.
But I think my Hayes clutch doesnt work with Corvette geometri, only chanse to disengage clutch i to adjust the pedal so it has absolutly no free play in pedal...
Read the thread below. We have such a small amount of travel in these cars that if a clutch doesn’t release in .550 inches or so they won’t work. Many aftermarket clutches fall into this category. This was an excellent thread by a very knowledgeable guy. It was in a C2 but same thing in a C3.
Thats why I think I have problem with the Hays clutch, probably it dont release at .550”.
Then There isnt much I can do? Just buy another clutchkit....?
I mean I have adjusted the pivot so I just have som freeplay on the clutchfork, then There is zero freeplay in the pedal....can I do something different?
I had the same issue with a clutch replacement a while back. I contacted the clutch manufacturer and , like someone else said, they told me to just give it a tiny bit of clearance. I did and it works fine. I initially thought that it was the release bearing dimension. After checking three different release bearings, they all had different dimensions, not huge differences but they were different enough. I asked about the "critical" specified distance between the pivot ball and bell housing face and they said don't worry about it.
I had the same issue with a clutch replacement a while back. I contacted the clutch manufacturer and , like someone else said, they told me to just give it a tiny bit of clearance. I did and it works fine. I initially thought that it was the release bearing dimension. After checking three different release bearings, they all had different dimensions, not huge differences but they were different enough. I asked about the "critical" specified distance between the pivot ball and bell housing face and they said don't worry about it.
thats my thought, as long as I get a Tiny space between clutchfork/bearing/pressureplate, the measurement between pivot and bellhouse ”edge” isnt so importent?
From: At my Bar drinking and wrenching in Lafayette Colorado
Most Hayes pressure plates require .780" of throwout bearing travel in order to fully disengage. The Corvette clutch linkage has a total travel distance of .580". You can adjust the linkage any way you want, and you'll never get .780" travel out of the linkage. You better set that pressure plate up in a press and test it before you finish your assembly - chances are really good (or bad...) that the Hayes pressure plate will not fully disengage at .580". If that's the case, don't install it. Changing the height of the fork pivot ball has no effect at all on clutch linkage travel.
Most Hayes pressure plates require .780" of throwout bearing travel in order to fully disengage. The Corvette clutch linkage has a total travel distance of .580". You can adjust the linkage any way you want, and you'll never get .780" travel out of the linkage. You better set that pressure plate up in a press and test it before you finish your assembly - chances are really good (or bad...) that the Hayes pressure plate will not fully disengage at .580". If that's the case, don't install it. Changing the height of the fork pivot ball has no effect at all on clutch linkage travel.
Lars
yes, Thank you. How about drill another hole (lower)in the z-bar? From What I understand it help increase travel?
which clutch (brand) can you recommend for corvettes with onley .580” travel?
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Mcleod will give full disengagement. And I went with speed direct clutch linkage with the heim ends. https://www.speeddirect.com/index.php/rod-links. That way you dont have to adjust the ball height. Lars had a great right up on the ball pivots and mcLeods clutches....
Some McLeod info they told me. Their pressure plates for the single disc design are all the same, the disc themselves are what changes the horse power rating, and you can get the discs alone at Summit, probably other retailers as well. So as long as you dont groove the flywheel you can upgrade as your power increases
And some clutch companies may allow for the throw out bearing to constanly rotate on the clutch fingers, depending on the manufacture, read that in their hydraulic cthrowout bearing instructions I believe
Last edited by Rescue Rogers; May 23, 2020 at 08:40 AM.
Did some measurement on this mcleod clutch today.
It took about 0.500 stroke before there was 0.050 clearance, I could move the feelergauge at 0.480, but it was tight.
Im happy with this and going to install it.
Throwout bearing clearance?
