Clutch problems...............
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Clutch problems...............
Took Stan's (Roadracevette) old #2 out today for its first taste of sunlight in almost 2 years. Ran great with the Ram Jet ZL-1 but as I turned for home something happened to the clutch...............car almost would not pull at all ........as if the clutch were slipping badly. Looked around and saw nothing broken with the linkage. Limped it back home and not sure what's going on. It's almost as if the clutch fork or some of the linkage was bent, but it's not. Adjusted the clutch to where it would normally engage with the pedal about an inch or two off the floor, but it still isn't right. Clutch will barely engage at all.
Suggestions?
Thanks,
Rex
Suggestions?
Thanks,
Rex
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If you have pedal freeplay at the top and the linkage is not binding and you can get the clutch to disengage enough to shift without grinding then it sounds as if clutch is gone or the disc is binding on the input shaft.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Clutch disc and pressure plate were both new when I put the engine in a couple weeks ago and this is the first drive for it. Is it possible for a pressure plate to collapse? It's a Zoom street assembly, diaphragm type with short throwout bearing. First time I've experieinced this. I did notice that when the pedal was depressed it seemed to be in a bind somewhere.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Yes I've seen brand new clutches go bad. Hopefully the binding you felt is on the outside somewhere in the linkage. Ive seen the throwout bearing installed wrong and cause binding on the input snout of the trans.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Thanks Roger. I'll have to get it up on some stands and remove the bottom half of the scattershield to see what's going on. Pretty sure the TO brg is in correctly and the clutch linkage and fork are the same ones that Stan used when he had a smallblock in the car. Hopefully it's something "relatively simple" (if that's possible).
Thanks,
Rex
Thanks,
Rex
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Clutch fork is binding against floorboard (I've never seen that!), actually stuck against it. Anyone ever experienced this problem, and if so, what was the resolution? Could the clutch rod be too long? Are there different length rods?
Thanks,
Rex
Thanks,
Rex
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Motor mounts are indeed aftermarket, but engine doesn't seem to be out of normal position. Clutch fork is the same one used in this car with a small block engine.
After some thought (that was painful)..................IF............ ..IF I used a FLAT diaphragm pressure plate rather than a RAISED diaphragm one, in conjunction with a short TO bearing (rather than a mid length one), this may be my problem. Solution it seems would be to replace the TO brg with the mid length one. Now the problem is getting the trans slid back far enough. Is it possible?
After some thought (that was painful)..................IF............ ..IF I used a FLAT diaphragm pressure plate rather than a RAISED diaphragm one, in conjunction with a short TO bearing (rather than a mid length one), this may be my problem. Solution it seems would be to replace the TO brg with the mid length one. Now the problem is getting the trans slid back far enough. Is it possible?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Motor mounts are indeed aftermarket, but engine doesn't seem to be out of normal position. Clutch fork is the same one used in this car with a small block engine.
After some thought (that was painful)..................IF............ ..IF I used a FLAT diaphragm pressure plate rather than a RAISED diaphragm one, in conjunction with a short TO bearing (rather than a mid length one), this may be my problem. Solution it seems would be to replace the TO brg with the mid length one. Now the problem is getting the trans slid back far enough. Is it possible?
After some thought (that was painful)..................IF............ ..IF I used a FLAT diaphragm pressure plate rather than a RAISED diaphragm one, in conjunction with a short TO bearing (rather than a mid length one), this may be my problem. Solution it seems would be to replace the TO brg with the mid length one. Now the problem is getting the trans slid back far enough. Is it possible?
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Like this?????????????????? http://www.jegs.com/i/Lakewood/620/15501/10002/-1
I do have a lakewood 2 piece bellhousing and used a new GM clutch pivot ball. I thought I saw a post somewhere here recently regarding 2 different length GM pivot ***** and if the wrong one was used (1.5 inches long) it caused problems with clutch geometry.
Now, back to my other question. If indeed I used the wrong TO brg, can the trans be slid back enough to replace the TO brg? Procedure?
Or...................would it be easier and just as effective to install the adjustable pivot ball?
Thanks,
Rex
I do have a lakewood 2 piece bellhousing and used a new GM clutch pivot ball. I thought I saw a post somewhere here recently regarding 2 different length GM pivot ***** and if the wrong one was used (1.5 inches long) it caused problems with clutch geometry.
Now, back to my other question. If indeed I used the wrong TO brg, can the trans be slid back enough to replace the TO brg? Procedure?
Or...................would it be easier and just as effective to install the adjustable pivot ball?
Thanks,
Rex
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Now I'm thinking it may be easier to just unbolt the engine, lift it and slide it forward a foot to install the correct TO brg,..... IF indeed that IS the problem.
Your thoughts?
Thanks,
Rex
Your thoughts?
Thanks,
Rex
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I take the trans out and put it back in several times during a clutch replacement to make my checks before installing the the shifter.
One time in and out with the trans is "without the clutch installed" to check pilot bushing fit , alignment and drag.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Yes a Hurst shifter, but it has the removable handle. What about the drivehshaft........................enoug h room to slide it back in order to remove the trans?
Last edited by Dr L-88; Jul 3, 2009 at 12:11 PM.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Do any other replacements, besides CF, supply dimensions for pivot ball distance, bellhousing indexing, etc.?
Following CF dimensions, I have had no problems with their clutch in over 4 years of use.
If the other mfgs. supply dimensions, are you checking and adjusting, as needed?
Following CF dimensions, I have had no problems with their clutch in over 4 years of use.
If the other mfgs. supply dimensions, are you checking and adjusting, as needed?
Melting Slicks
Joined: Sep 2003
Posts: 2,114
Likes: 33
From: ct
One tip. Once you set the ball and know it;s right tack weld the jamb nut. They like to come lose.
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Thanks for the info Brian. Even though I installed a 2 piece scattershield, I CANNOT get the bottom half off. I know that whatever the problem is I will still have to pull the trans, but I would at least like to get the bottom of the shield off so I can determine if the pressure plate has collapsed or if I just used the wrong TO brg. Looks like I'll be under the car tomorrow...............already got it up on stands.
Thanks for everyone's input.
Rex
Thanks for everyone's input.
Rex
Thread Starter
Le Mans Master
Joined: Oct 2007
Posts: 5,996
Likes: 1,727
From: Richmond Kentucky
2025 Corvette of the Year Winner- Modified
2024 C2 of the Year Winner - Modified
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
OK...................here are some pics to hopefully help identify the root cause of my problem. I've never experienced a clutch problem of this type. First pic shows the damaged throwout bearing with part of the retaining collar broken (that's the "metallic pop" I heard on the test drive) that was found lying in the bottom of the bellhousing when removed. Other pics show the flywheel with raised diaphragm so I DID use the correct short TO brg. Other pics show parts of the clutch linkage that Stan used when he had a smallblock engine in the car.
I'm open to ANY and ALL suggestions. An adjustable clutch pivot ball is on order and should be here tomorrow.
Thanks in advance for your help and advice.
Rex
I'm open to ANY and ALL suggestions. An adjustable clutch pivot ball is on order and should be here tomorrow.
Thanks in advance for your help and advice.
Rex