Clutch experts/help
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Clutch experts/help
I have a rebuilt Muncie and a Mcleod street twin clutch with aluminum flywheel and Lakewood scattershield. Also an adjustable pivot ball and stock fork. I have about 800 miles on this setup and has been trouble free. In the last couple of days I have developed an intermittent problem where the clutch will disengage almost immediately off the floor spinning the tires. When it does this it shifts through the gears normally. Even from a slight roll it is normal. However when stopped or on a slight upslope, any clutch movement engages driveline. Then it will go away just as fast. I assume it is an adjustment to the clutch but why would it be intermittent.
Safety Car
Joined: Aug 2001
Posts: 3,892
Likes: 13
From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
I read your explanation 3 times, still don't totally understand the problem. Do you mean the clutch ENGAGES when you let the clutch pedal move away from the floor, there by engaging the drive train and causing it to spin the tires?
What does "then it will go away just as fast" mean?
Sorry I must not be too bright, but I would like to help if possible.
What does "then it will go away just as fast" mean?
Sorry I must not be too bright, but I would like to help if possible.
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
John, yes when I am stopped and I slowly start to let the pedal out the clutch will grab immediately. Then I can go to the next light and it will work normally. Very strange. I thought maybe oil might be leaking onto it but it is clean and dry underneath he car, no drips. I am very close to the end of the clutch rod on adjustment. Up until now this clutch has worked perfectly.
Safety Car
Joined: Aug 2001
Posts: 3,892
Likes: 13
From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Boy, that does not make sence at all. I would get the car up on jack stands and get under it and check every thing clutch related. With the amount of pressure clutchs work under I can't imagine something working, and then not working, and then working again.
Good luck
Good luck
Advanced
Joined: May 2005
Posts: 99
Likes: 0
From: Lincolnton NC
just a thought, the bolts that hold the pressure plate to the flywheel: do they have "shoulders" , or are they all-thread? Of course you should have bolts w/shoulders (a section unthreaded under the hex head) to prevent any posible movement of the pressure plate. 
good luck, jim
good luck, jim
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Melting Slicks
Joined: Nov 2001
Posts: 2,668
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From: Eastern US XX
Originally Posted by 69ttop502
I have a rebuilt Muncie and a Mcleod street twin clutch with aluminum flywheel and Lakewood scattershield. Also an adjustable pivot ball and stock fork. I have about 800 miles on this setup and has been trouble free. In the last couple of days I have developed an intermittent problem where the clutch will disengage almost immediately off the floor spinning the tires. When it does this it shifts through the gears normally. Even from a slight roll it is normal. However when stopped or on a slight upslope, any clutch movement engages driveline. Then it will go away just as fast. I assume it is an adjustment to the clutch but why would it be intermittent.
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
OK, got the car up on the stands and I can't for the life of me find anything. The motor mounts and transmission mounts are brand new and look fine. No oil drips coming from anywhere near the bellhousing. The clutch rod and Z bar look fine although the rod is not perfectly straight. It has a slight bend in it shortly after it comes out of the firewall. Is this normal? Could it be fatigued and collapsing allowing movement? I didn't have anyone to push the clutch in for me while I was under the car but all looks OK. This is a stumper so far. Any ideas?
Bill
Bill
Race Director
Joined: Feb 2005
Posts: 16,100
Likes: 17
Originally Posted by 69ttop502
OK, got the car up on the stands and I can't for the life of me find anything. The motor mounts and transmission mounts are brand new and look fine. No oil drips coming from anywhere near the bellhousing. The clutch rod and Z bar look fine although the rod is not perfectly straight. It has a slight bend in it shortly after it comes out of the firewall. Is this normal? Could it be fatigued and collapsing allowing movement? I didn't have anyone to push the clutch in for me while I was under the car but all looks OK. This is a stumper so far. Any ideas?
Bill
Bill
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Ok, here is an update on the problem. I drove the car again yesterday and the problem is no longer intermittent. It is happening every time. The smallest movement letting the clutch off the floor results in instant grabbing. I also am noticing a small amount of engine oil dripping off the bottom of the bellhousing. So I guess I have it on the flywheel. I did just change the intake but checked and there are no leaks from the distirbutor, intake, valve covers or oil pressure fitting. The back of the block is clean.
So I guess my questions are is the mainseal the only other place this oil can come from? It is a new engine with the one piece seal. I hate to think I have ruined a new and very expensive clutch. I am going to call Mcleod today to see if they have any ideas. Otherwise the tranny looks like it is coming out. I will finally cut my crossmember this time. Any ideas would be appreciated.
So I guess my questions are is the mainseal the only other place this oil can come from? It is a new engine with the one piece seal. I hate to think I have ruined a new and very expensive clutch. I am going to call Mcleod today to see if they have any ideas. Otherwise the tranny looks like it is coming out. I will finally cut my crossmember this time. Any ideas would be appreciated.
Race Director
Joined: Feb 2005
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Originally Posted by 69ttop502
Which way would I adjust the rod to try to get rid of this? Thanks for your help Rihwood.
1.Disconnect the spring between the clutch pushrod and cross shaft lever.
2.While holding the clutch pedal against the stop, loosen the two locknuts enough to allow the adjusting rod to move against the clutch fork until the throwout bearing touches the pressure plare springs.
3.Turn the upper nut against the swival and back it off 4 1/2 turns.Tighten the bottom locknut to lock the swival against the top nut.
4.Reinstall the return spring.Your pedal free travel (the distance your pedal can be moved before the throwout bearing contacts the pressure plate spring) should be 2"- 2 1/2" (with heavy duty clutch.
This info is in Chiltons Corvette 63-82 Repair Manual section 7-10 fig. 13.
I suggest this first,before jerking your tranny.I have a stick with very small leak where you describe.But from your description,It appeared to me your free travel is right off the floor,like about an inch or so...
Glad to have helped..
Instructor
Joined: Apr 2003
Posts: 144
Likes: 0
From: Neenah WI
Also look at your fork and Ball. I just had a similar thing like this happen but I also started having issued with disengagement as well. did it more for 1st and reverse.
My fork slid in toward the throw out bearing vs staying put on the pivit ball.
As far as adjusting goes. away from the firewall tightens toward the firewall Loosens.
IF you are toward the end of the adjusting rod you will also wish to replace the clutch fork as I have learned the stock versions tend to bend over time. I found this out after I made a longer adjusting rod.
My fork slid in toward the throw out bearing vs staying put on the pivit ball.
As far as adjusting goes. away from the firewall tightens toward the firewall Loosens.
IF you are toward the end of the adjusting rod you will also wish to replace the clutch fork as I have learned the stock versions tend to bend over time. I found this out after I made a longer adjusting rod.
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Thanks 69, so when you say tightening you mean it engages closer to the floor? So I want to loosen mine based on your info, right. Thanks for the info. Thanks again to Rihwoods also. I am gonna get started in a few minutes.
Thread Starter
Le Mans Master
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Thanks Nick. I fooled around with the adjustment again and it seems like it is correct. The free play is right in spec. Damn is it hot in that garage right now. I disconnected the linkage and it seems all is OK with the fork and bearing, at least as much as I can tell without moving anything. Nick, take me for a ride in the yellow beast to remind me how much I like my car. AAARG!