# Clutch Will Not Disengage



## jtwoods4 (Dec 22, 2011)

Ok, I have a very weird problem. Last weekend I removed the Pontiac 455 engine from my 69 GTO. I replaced it with the original 400 block stroked to a 461. I got the new engine fired up and adjusted today. I reconnect all the clutch linkage and zbar. This was the same clutch linkage and zbar that was on the car when I had the 455, all stock clutch parts. It was all working perfectly fine with the 455. However, now that I have replaced the engine the clucth will not disengage, in other words I cannot shift while the engine is running.

I CAN shift when the engine is turned off, but CANNOT when the engine is running. I just figured I would increase the length of the adjustable rod that makes contact with the clutch fork. So I lengthend it about a half inch. Still no go.

Since the 455 and the 400 block are idnetical in size and the clutch was working fine on the old engine I have no idea what is going on.

Throwout bearing is the exact same size as the one used with the old engine and old clutch. Old clutch was by zoom. New clutch is by McLeod.

Same bellhousing, Same transmission, same clutch fork, same shifter, only thing that has changed is the engine and clutch.

This is the McLeod cluctch that is installed
http://www.summitracing.com/parts/mcl-75221/

Any ideas? I am stumped.


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## geeteeohguy (Feb 2, 2008)

Clutch disc in backwards? It can happen, and it'll give you your symptoms. Another thing: did you change the flywheel bolts? Aftermarket bolts can have heads that are too high, and they interfere with the clutch, and can also cause your problem. If you feel the clutch springs/diaphragm push in when you apply the pedal, your T/O and Z bar are probably OK.


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## jtwoods4 (Dec 22, 2011)

I remember checking 2 times to make sure the clutch disc was not in backwards. I am starting to think that the throwout bearing included with the McLeod clutch maybe to short. It was the same size as the other bearing I was using with the zoom clutch but the zoom clutch fingers may have stuck out more. If the McLeod fingers are more "flat" then the same size TO bearing could not be used. Maybe McLeod includes the wrong size bearing with their kit.....


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## jtwoods4 (Dec 22, 2011)

Maybe the throwout bearing that comes in the McLeod kit is too short. Would I have the same symptons of shifting while engine is OFF but not when engine is ON if the TO bearing was to short? I think this may be the issue.


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## geeteeohguy (Feb 2, 2008)

Normally, your pedal feel (travel and free-play) would feel strange if the T/O bearing was too short...your pedal would not have the full travel, and the height would be lower. Do you have a full stroke of the pedal? Also, Borg and Beck (finger type) clutches use a different T/O bearing than the Diaphragm clutches do, typically....


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## jtwoods4 (Dec 22, 2011)

Well I measured the old clutch pressure plate fingers to the clutch disc splines. Turns out the distance on the new Mcloed clutch is an inch shorter. However the McLeod clutch kit came with the same size throwout bearing. Turns out McLeod sells a longer bearing on their website that solves the problem. I just ran down to summit racing and bought the McLeod adjustable bearing. Looks like McLeod has found a way to make an extra Buck. Wont be buying Mcloed again.


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## ALKYGTO (Mar 29, 2010)

Did the TOB come with the clutch kit?

If so I would call Mcloed and see if they will refund the price of the bearing. 

Mcloed has excellent customer service and product, I would'nt be so quick to judge. I know it's frustrating but it's part of the hobby really. :cheers


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## jtwoods4 (Dec 22, 2011)

ALKYGTO said:


> Did the TOB come with the clutch kit?
> 
> If so I would call Mcloed and see if they will refund the price of the bearing.
> 
> Mcloed has excellent customer service and product, I would'nt be so quick to judge. I know it's frustrating but it's part of the hobby really. :cheers


Yeah I just get impatient, struggled with that all my life. Working on these cars is really a sick obsession. But the payoff is so worth it.

Half inch taller throwout bearing installed. Shifts great. Tranmission installed in record time .


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## geeteeohguy (Feb 2, 2008)

Don't be too hasty about McCleod. I've had the same McCleod unit in my '65 since like, 1984. Still fine. Impatience while working on cars will cost you time and money, as you already know. The older I get, the more patient I am, and the better work I turn out because of it. Remember, this is supposed to be FUN!!


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## jtwoods4 (Dec 22, 2011)

Just got off the phone with McLeod, since the throwout bearing was included in the Super Street Clutch kit they cannot refund the cost of the TO Bearing. Oh well, I am just glad the taller one worked.


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## PontiacJim (Dec 29, 2012)

*Two sizes of throw-out bearings*



jtwoods4 said:


> Well I measured the old clutch pressure plate fingers to the clutch disc splines. Turns out the distance on the new Mcloed clutch is an inch shorter. However the McLeod clutch kit came with the same size throwout bearing. Turns out McLeod sells a longer bearing on their website that solves the problem. I just ran down to summit racing and bought the McLeod adjustable bearing. Looks like McLeod has found a way to make an extra Buck. Wont be buying Mcloed again.


I know you already solved the problem, but for future note. I learned this working on my cars. There are 2 sizes of throw-out bearings, the "long" and "short" depending on the type of clutch fingers used on the pressure plate; the diaphragm type, Borg & Beck, Long, or some combination thereof. The next thing to check is the pivot ball found inside the bellhousing. This too can be "short", "long", or "adjustable". If you know you have the correct throw-out bearing, and clutch linkage is working properly, then it may be here that an adjustment needs to be made if you are still not getting a clean shift. Finally, I purchased an aftermarket clutch fork for my '68 Lemans. Original was badly worn. The fork was similar, but not exact. It work, so I used it. What happened was the cut out which creates the fork arms was too deep and there was nothing to hold it in place other than the spring clip over the pivot ball. The fork slipped off the ball, positioned the fork deep over the throw out bearing, and when I pressed it in, it busted the edge off the throw-out bearing collar and it went into the pressure plate taking out 2 of the small hub springs on the clutch disc and sending one into the pressure plate which took out a couple of those springs. $400 out the window. Found an original clutch fork, new clutch set-up, and no problems since.


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## jtwoods4 (Dec 22, 2011)

I hope my pivot ball is tall enough because it is tack welded in place to the scatter shield bellhousing. Shifts fine while engine is cranked and sitting at idle. Going on maiden voyage tomorrow.


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