I have read all of the posts about this but I can not figure out what is wrong here with mine.

Everything looks exactly the same and measures what basically was in there. I had a 6 cylinder motor in the car and am switching to a 350. I measured the flywheel/clutch assembly from the rear of the 6 cylinder motor and it is the same as the 350, I compared the clutch forks and they are exactly the same, the lakewood scatter shield is the same measurements as the original, but still when I bolt everything up, the clutch fork hits the firewall...Has anyone had to beat the firewall in to make this work? Any ideas of what could be wrong would be greatly appriciated.

You shouldn't have to beat the firewall.
An adjustable pivot ball may help.
With all of the issues you've run into lately (motor mounts don't fit right, headers fouling the power steering, and now this) I think I'm gonna hafta continue to insist that your motor's in the wrong place due to a bad combination of motor mounts and frame stands!

I have the adjustable piviot ball and put in in per the lakewood recommendations of 4.75" from the engine block. I have tried two sets of motor stands or pearches, and three different motor mounts. I normally dont cuss but this morning after having to pull the motor and trands and all those bolts for the scatter shield out, the neighbors 3 streets down were wondering if I was killing someone!!!! I dont think that I am going to be able to get that much adjustment out of the piviot ball. When the motor is in, the free play of the clutch fork was hitting the firewall, maybe just touching the clutch...I dont know how much movement there has to be from when the fork hits the clutch...

Interesting situation and I am waiting to hear the solution. I have a buddy that bought a 68 Z28 (now with a 350) and he is having the same issue. I can tell you beating in the firewall will not cure the problem. That is the fix the previous owner attempted. My buddy brought the car over because he felt it wasn't running like it should. I had him push the pedal to the floor as I looked at the throttle blades (Holley DP). I saw he was only getting about half throttle. Long story short the problem was/is caused by the floor being dented to clear the clutch fork. The gas pedal will no longer go down far enough to actuate the carb to full throttle. As a bandaid fix I modified the pedal, it would have been a much better idea to have the proper mounts in the first place. I am 99% sure the problem is the engine/frame mounts. His distributor is flush against the fire wall, so tight it actually cracked the cap. I think Jim is right there has to be a mount issue of some sort.

I made this conversion and it worked perfect. I think you've got the wrong frame mounts. You need a C794 and C795 to make this work. The 6-cyl stands won't cut it.
http://www.stevescamaroparts.com/sitebuildercontent/sitebuilderfiles/engine.pdf
or rick's sells them in the pair EP-4 on page 215
http://www.firstgen.com/catalog/Ricks-202-233.pdf

I have plenty of room between the cap, motor and firewall...I got the frame mounts from classic, part number 3955184. I guess I will try a different mount and motor mounts again...

I have plenty of room between the cap, motor and firewall...I got the frame mounts from classic, part number 3955184. I guess I will try a different mount and motor mounts again...
can you post a pic? I'll take a pic of mine tomorrow and post.

What pressure plate are you using? Some plates (like Macleod) require a tall throwout bearing because the plate has a lower profile than the stock plate.

I can take pics but I am not sure what to take it of...I had the motor in the car and all bolted up...now it is out and everything is back apart in peices because I wanted to check everything. This is the 6th time I had this thing in and out. Let me know which part you want me to take a pic of and I can post it.

I got the centerforce clutch kit and throwout bearing from Jegs.

I have about $14000 into this thing and I am ready to sell it. If anyone wants to buy it as it sits I would take 10000 for it.

Don't do that you will figure it out. Sometimes it is madding tho. LOL

Clutch fork geometry is off,if yo got the right fork. no two ways about it. Been there , done that.

It's not your motor mounts since you have alot of space between the distributor and the firewall. I'd be willing to bet you have the wrong throwout bearing. I had the same issue in my 68 years ago when I went to a Macleod 3 finger clutch. Ended up using a 6 cylinder throw out bearing in it because it was about an inch taller than the V-8 bearing. The taller throwout bearing moved the outer end of the clutch fork forward away from the firewall.

Did you read this post? Noy using a lakewood clutch fork are you?

http://www.camaros.net/forums/showthread.php?t=22119&highlight=fork+firewall

Or this one:

http://www.camaros.net/forums/showthread.php?t=51397&highlight=fork+firewall

Here are pics of the fork...They are almost identical...

http://i16.photobucket.com/albums/b22/Liveinaz/clutchfork/MVC-003F.jpg

http://i16.photobucket.com/albums/b22/Liveinaz/clutchfork/MVC-002F.jpg

http://i16.photobucket.com/albums/b22/Liveinaz/clutchfork/MVC-001F.jpg

Mark,

I think you are on to something. Here is the difference between the two throw out bearings...

http://i16.photobucket.com/albums/b22/Liveinaz/clutchfork/MVC-004F.jpg

can you get us a pic of the pressure plate fingers?

The part numbers on your clutch fork is the one for the 11" clutchplate. The 10.4" one (Part # 3892632) might work better, but the throwout bearing is cheaper.

Is this what you mean by the fingers Jim?

http://i16.photobucket.com/albums/b22/Liveinaz/clutchfork/MVC-005F.jpg

Yes, that's exactly what I mean. I think we need to hear from someone who has used one, I'm only used stock type clutches, but it seems to me that the bend near the end of the fingers would put the height of the unit lower than a stock type clutch and it might need a different arrangement of parts to get the linkage right. It's not as low as a borg and beck tho, so I'm not real sure...

I am thinking it is the throw out bearing...there is about an inch difference. Is it okay to use a throw out bearing from a 6 cylinder, or do they make a taller bearing that anyone knows of?

The part numbers on your clutch fork is the one for the 11" clutchplate. The 10.4" one (Part # 3892632) might work better, but the throwout bearing is cheaper.

I have the Centerforce DF setup and the 10.4" clutch fork mentioned here with no problem using a stock throwout bearing. When I bought the car it was hitting the firewall with a fork that looked identical.

I am pretty sure I have the 11" clutch plate...should I use the fork for the 10.4" plate? to me the only differences I can see are the throw out bearing heights...

I bought the heavy duty GM clutch fork from Jegs...I do see that they have an "oversize" throwout bearing listed, so I wonder if that is the one I need....

I bought the heavy duty GM clutch fork from Jegs...I do see that they have an "oversize" throwout bearing listed, so I wonder if that is the one I need....
I know you're working on this now, but you might want to give a call to Centerforce to ask about which t/o bearing to use. I don't think it's the frame mounts now that I know you have room at the distributor.
Good Luck! Don't sell the car.

PS I just read some of the previous posts on this issue. Which t/o did you have in it? I remember having discussions about this issue when I did mine. The longer t/o is probably what you need.

Yeah, I will give them a call on tuesday. there is plenty of room between the firewall and the motor...I have about two inches behind the distributor with the bigger HEI cap on it and I can probably take out most of the bolts from the scatter shield with enough clearance there...

I tell you, this is my first time doing something like this and it gets frustrating to say the least. I dont really have anyone I can talk to about this except for the people here which have been a great help. I wanted this done by the first of the year, but I can tell that isnt going to happen. I will most likely keep the car but that could change at the next problem I encounter...LOL.

I am using a Centerforce II like the one pictured. I am using the stock GM fork for my 69 Camaro. I am using the BCA 1705 CC throw out bearing ... You can also get this from Autozone under Part # 614018 Timken . Its a sealed bearing.

I believe Centerforce calls it N 1716 bearing but if you read numbers off the bearing itself, you may find it changes over to Timken or BCA

That's your problem right there. I had this same problem in my 67 Firebird when I changed it over. I used the throw out bearing that came with the clutch kit and had no use of the clutch, The arm hit the firewall and the clutch wasn't even close to being released. I called Zoom and they recommended the taller throwout bearing. Once I changed it my alignment and clutch operation was perfect. Call Summit/Jegs and tell them you need a GM tall throwout bearing. It'll run you around $50, but will fix all the problems.

zdld17,

I just ran up there and checked it out...it is basically the same size as the shorter one that I have. I need to find one that is like an inch taller simalar to the one in the picture...

I only mentioned this because of the picture of the Centerforce clutch .There are only 3 bearings that can be used. You eliminated one. This can't be all that complicated . I had the same problem with forks hitting firewall , until I changed to adjustable ball stud. It works for me . I think I am running the same 11" plate as you but I seem to notice in the picture you posted,,, your bent fingers are more bent than mine. So that makes sense if you need a taller bearing. Problem here is that Centerforce shows only one bearing (the one I am using) as the correct bearing for all of their II plates.. Why yours is differant? Chemosabe.

the box is from centerforce and the part number on it is N1716...as far as the other taller bearing in the picture, that is from the 6 cylinder motor with a 3 speed transmission that was in the car originally. It is crazy...you would think they would have a taller one available and based on what 69x11 says, Jegs or Summit has them available...I guess that is what I am going to have to search for, along with calling centerforce.

Wait for stores to open up on Monday,, go down and get them to take out all release bearings for gm applications and lay them on counter. Autozone is gonna be tough as they cant find anything without going to computer.. If all else is correct , then its gotta be the bearing but I keep going back to geometery.

Merry Christmas!

Now that I am thinking about it,, The 6 cly uses the bellville type pplate and that would call for a tall bearing but I think the bearing flats ( mating surface ) is wrong? Sorta rounded. ?

The wrong bearing does affect the geometry. My 69 Camaro is a factory V-8 car with either the 327 or 307 and it uses the same 'tall' bearing as the one your pictures show for the 6 cylinder application. Maybe get a throwout bearing for a 69 Camaro with a 307 3 speed, it should be the right one.My car had the stock diaphram clutch in it when I tore it down.

Linenaz, Check this # out when possible,,614037 , According to Timken applications, this is for bent diaphram plates. 614018 of for Flat plates... You said you already have a N1716 and thats the 614018, so try the other part #... Good luck..

http://www.timken.com/industries/automotive/autoaftermarket/timkencatalog/PartCatalog.aspx

I bought the heavy duty GM clutch fork from Jegs...I do see that they have an "oversize" throwout bearing listed, so I wonder if that is the one I need....

I tried that fork and it was solidly into the firewall. I think it's for a 2nd gen although advertised as HD. It definately will not work. Get the correct GM one and persevere.

I tried that fork and it was solidly into the firewall. I think it's for a 2nd gen although advertised as HD. It definately will not work. Get the correct GM one and persevere.
Rick,You are 100% correct, I tried to use that Jeg's clutch fork and it hit the firewall, had to use my original. Now the jeg's fork is collecting dust on the side of my tool box.
I am running 11 in. CFII, Billet CF flywheel, Lakewood bellhousing, short throwout bearing with the stock clutch fork works great.

Kind of strange because the exact same numbers are stampped on each of the forks...the new one from Jegs and the original one...also in comparing them side by side, the geometry is almost identical, withing less than 1/4" max...as indicated in another post on here, I am now looking at the possibility of a piviot ball adjustment...I do notice in the Classic catalog, there is a different fork listed for a 67 Camaro which is a reproduction of the forks used on 1967 models...jcdubs, maybe since you have a 67 Camaro, yours required a different fork than the 68 models...

The part number for the fork's you have now 14066235 will not work properly with first gen Camaro's. This is a direct quote from Jeg's:

GM Clutch Forks
Fits most intermediate applications such as 1973-79 Camaro/Firebird, Nova, Malibu and some trucks. Replacement for GM part numbers 340278 and 14066235.

Here is another quote from Lakewood's knowledgebase about their clutch fork with the same 14066235 part number:

The 15500 is the GM universal clutch fork. You need the OEM fork for a camaro.The 15500 will not work in a camaro. You can get it from year one or camaro restoration companies. Thanks


You should try the original GM fork part number 3892632, which in my parts book shows for all clutch sizes.

MIke

Okay, I will order one tomorrow and try that along with the pivot adjustment...

You should try the original GM fork part number 3892632, which in my parts book shows for all clutch sizes.

MIke

Yup that is the fork you need #3892632.

Use an original V8 fork and the short throw-out bearing. You will also need to set your pivot ball height to the correct demension. Flywheel thickness, block saver plate play a major role in the set-up height. GMJim has an excellent .pdf file on what the 5-7 degrees forward fork tilt should look like.

If you measure your flywheel and blocksaver thickness I will figure out your total pivotball height to get your 5-7 degrees forward tilt.

Jody,

The flywheel thickness is 1-1/4"
There is a 3/8" space between the flywheel and the block plate
Just under 1/8" for the block plate (lakewood)
Total from the block to the face of the flywheel is 1-3/4 to 1-7/8"

Rick,You are 100% correct, I tried to use that Jeg's clutch fork and it hit the firewall, had to use my original. Now the jeg's fork is collecting dust on the side of my tool box.
I am running 11 in. CFII, Billet CF flywheel, Lakewood bellhousing, short throwout bearing with the stock clutch fork works great.

Yup.. ive done that one too.. That jegs fork wouldnt fit my car either after switched to a Centerforce DF and centerforce bearing. I ended up using my older 6 cyl fork over again. I think the centerforce clutch moves it a bit closer to the firewall. At least it seemed like it to me. That longer throw out bearing my correct that problem though..

Also...... I ont know what your body mounts look like.... but if the body mounts are crap.. the car sags on the frame resulting in less clearance in that shi fork area..(another one of my problems.).. might want to look into that as well..

Yeah, I am sure I had the wrong fork. I found the correct fork at my local Chevy Dealer here in town. The fork that was originally on the 6 cylinder must have been the wrong one too since the one from Jegs and the old one from the 6 cylinder have the exact same numbers stampped on them...The new one I got today is the 3892632 part and is like a good 1/2" shorter. They must have redid the original 6 cylinder clutch and used the wrong fork...

Now, my situation is making sure I get the pivot ball in the correct location. I posted the numbers above, so I am hoping to hear back on what the pivot ball should be set at....

Jody,

The flywheel thickness is 1-1/4"
There is a 3/8" space between the flywheel and the block plate
Just under 1/8" for the block plate (lakewood)
Total from the block to the face of the flywheel is 1-3/4 to 1-7/8"

Lets take this one step at a time:

Place your flywheel on a flat and smooth table with the pressure plate surface side down. Measure through one of the crankshaft mounting bolt holes for the proper flywheel thickness. I would think you are measuring from the outer edge to get 1-1/4".

Yes, I was...actually I think I have it figured out. I subtracted the block plate from the 4.75 dimension recommended which gave me a hair over 4.5". So I went with that dimension and connected the bellhousing and it looks like I am within the 5 to 7 degrees. I had the clutch and flywheel on the motor when I gave the measurements earlier. I now have the motor in the car and everything seems pretty good. I think what I will do is try it out and see how it feels and if I have any problems, I can take it in and get some minor adjustmens if needed. I am sure the clutch linkage will need to be adjusted some. I did have and still have a bit of a problem with the spring connection since I dont have the original spring and wire rod. I will need to look into maybe getting that at some point too...

Yes, I was...actually I think I have it figured out. I subtracted the block plate from the 4.75 dimension recommended which gave me a hair over 4.5". So I went with that dimension and connected the bellhousing and it looks like I am within the 5 to 7 degrees. I had the clutch and flywheel on the motor when I gave the measurements earlier. I now have the motor in the car and everything seems pretty good. I think what I will do is try it out and see how it feels and if I have any problems, I can take it in and get some minor adjustmens if needed. I am sure the clutch linkage will need to be adjusted some. I did have and still have a bit of a problem with the spring connection since I dont have the original spring and wire rod. I will need to look into maybe getting that at some point too...

By the math numbers, your pivotball height might be too high. I would guess by your replies you are measuring your items with a ruler or something like it? You should use some precision measuring tools for this job.

If your pivotball height is too high, you can over depress/release the diaphram fingers. What does this symtom feel like? You won't have any engagement of your clutch and this usually will happen at high RPMs.The diaphram fingers can get reversed.

With normal operation, you will have a high pedal release feel and it will seem as if you cannot get enough pedal freeplay.

This is at an extreme condition, but it can happen.

In looking at the diagram, and into the bell housing, I am pretty sure I am close to the 5 to 7 degrees...I am thinking that at this point, since I have the motor back in, once I get to the point of being able to drive it, I am planning on taking it in to a transmission shop and have them do an inspection and adjustment. This is the first time for me on this and with all the problems i have had, I am probably better off letting someone adjust it the rest of the way...What do you think the height should be about on the piviot ball? From the lakewood pages, it shows 4.75" and taking into consideration of the block plate, I figured just over 4.50"...but I guess taking into consideration of the clutch and flywheel is necessary to get that 5 to 7 degree geometry...I am hoping that it is close and I dont have problems...thank you very much for all of your help Jody...

when you get right down to it, it's just some simple geometry. Since the headers and distributor fit now, the motor must be close to the right place... you have not changed the length of any of the levers, so... when it feels right, it will be right. Once it's all together, rough adjust the linkage for an inch of freeplay at the pedal. Once you can start it and make it move, fine adjust for engagement to start (car starts to roll) with the pedal 3-4 inches off the floor. Then check that you have some clearance between the fork and the firewall with the clutch on the floor.

LiveinAZ - I'm having the exact same problem as you - putting a ST-10 in my small block with a Lakewood scattershield and have fork 14066235 and I have only an 1/8 of an inch between fork and flywheel. I got this fork from a Camaro resto company (D&R Classic) - is this the one that didn't work for you, but a GM one did? Please let me know. I'm losing my mind on this after all of the z-bar hassle.

Nevin

You definetly have the wrong fork. The part number for the correct fork is 3892632. It is about 1" shorter in length from the pivot ball to the end that the push rod rides on.

I got the correct on from my local Chevy dealer who had them in stock. I would call around to the parts department at your local Chevy dealers and see if they have the 3892632 fork available. When I went in I had them check the other 140 number and it is from like a 73 to 79 Camaro...I paid $50 for mine, but I saw someone else that paid around $30 something...

Also, as Jody mentioned, the pivot ball height is important too...I am going to take mine to a trans shop and have final adjustments made after I get everything else on and the car running. I am sure Jody can give you the pivot ball height dimension if you contact him or he reads this...also there is a great picture of the 5 - 7 degree angle for the fork somewhere in this post...If you are like me, depending on the extent of what you are doing you will be taking those 25+ bolts out of the scatter shield more than a few times...

You can get that here for $38.79 shipped from here: http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=3892632

Mike

How much throw does the fork require? Based on Lakewood's recommendations I bought Hays throwout bearing 70-104 which is 1/4" taller, but I still only have about 5/8" of fork swing before it hits the sheet metal. My pivot ball is 1.5" tall, right in the middle of the 1-5/16 to 1-11/16 adjustable ball that the Lakewood guys suggested.
Here are my earlier notes http://www.camaros.net/forums/showthread.php?t=70441 (I figured I should keep the topic on this thread)
What's my next step? A longer pivot ball? This issue is seriously delaying my progress.

What exactly was in there originally and what have you done to this point? Did you do an engine swap, transmissions swap, or just changed over to the lakewood bell housing and new clutch? Have you done anything like remove the subframe?

I am building a rolling body that was purchased without a drive train. The car being an X33 coded Z28 has always been a 4-speed.
I then found and purchased a running drive train from a guy located in the northern region of the country. The drive train includes a DZ coded engine, Lakewood bell housing, M21 transmission, Hays clutch, etc. When I ask the guy about problems like this, he always responds "well it worked in my car". I really believe that he must have substituted some parts, and/or his car had been modified with a ballpein hammer.
I have checked the subframe by hanging a plumb bob from the center of the alignment holes and found it to be positioned correctly.
From another post I learned that the fork should be at a 5 to 7 degree angle toward the engine. I should be able to get that with an extended length pivot ball.
I am annoyed because I planned to work on the car this weekend, but I now must wait on the purchase of another part. Considering the amount of chatter on this topic this seems to be a common problem, and the Lakewood scattershield is almost always involved.

You should make sure you have the correct motor mount stands and they are installed correctly...they should hang off the back of the frame just a bit...do you have any pics you can post to get an idea of what may be happening? Is there clearance behind the motor and the firewall? you should be able to get to the upper bolts on the bell housing with at least a wrench...the thing I keep going back to is the clutch fork being wrong....

In the instructions from lakewood, it shows that from the engine block to the pivot ball it should be 4.75"...what I did was put a straight edge across the bell housing, and measured from the top of the pivot ball to the straight edge and subtracted a little over an 1/8" for the block saver plate. This got me real close to the correct height of the pivot ball...

The motor mount stands are correct and also installed correctly. I can take photos, but have no way to post them. I have sufficient clearance behind motor and firewall and can reach the bell housing bolts. I am sure that the subframe and engine are correctly placed.
I don't have the 5 to 7 degree angle that GMJim details in this thread: http://www.camaros.net/forums/showthread.php?t=69712&highlight=clutch+fork+hitting A taller (mid 80's Chevy 1/2 ton truck (per another thread)) pivot ball might get me that desired angle.
As much as I hate to perhaps today I can remove the bell housing and check that 4.75" measurement.
Many thanks to you, Liveinaz, for the assistance.

Kind of weird...I had the same situation but when I got the correct fork it solved my problem. Are you sure your fork is correct? Also that the fork is correctly installed onto the throwout bearing? The adjustable pivot ball from lakewood is part number 15501 and from Mr Gasket is part number 3855 and according to their instructions adjusts from 1.55" to 1.30"...if you are not getting that 5 to 7 degree angle, that seems wierd...maybe the throw out bearing is backwards or is the wrong one...kind of running out of ideas. maybe check that 4.75"...something isnt right...

My fork compared identically to the one at the GM dealer and it is installed correctly in the T/O bearing. I did replace the Hays T/O bearing with one 1/4" taller, which gave me 1/2" more swing, but not enough. My next plan of attack will be to check on the longer pivot ball stud at the GM dealer Monday morning.

Well the troubles continue. After much struggling trying to get the tranny in, I figured that I must have let the clutch disc drop when I cycled the clutch without the transmission in place.
To realign the clutch disc I have now removed the scatter shield which gave me the chance to determine the extended length ball-stud gives me a distance of 4.50". Considering that I am using a block plate I am looking for a distance of 4.625". How might that extra 1/8" affect my clutch action? The arm has a little slack toward the headers, and plenty of space to disengage the clutch, so I think things will work OK.
Also, there must be a good way to remove the scatter shield bolts. Do you guys use swivel sockets or something like that? Breaking the 3/8-16 bolts loose that had been torque wrench tightened was tough with a wrench, then just removing them was also very difficult.

Well the troubles continue. After much struggling trying to get the tranny in, I figured that I must have let the clutch disc drop when I cycled the clutch without the transmission in place.
To realign the clutch disc I have now removed the scatter shield which gave me the chance to determine the extended length ball-stud gives me a distance of 4.50". Considering that I am using a block plate I am looking for a distance of 4.625". How might that extra 1/8" affect my clutch action? The arm has a little slack toward the headers, and plenty of space to disengage the clutch, so I think things will work OK.
Also, there must be a good way to remove the scatter shield bolts. Do you guys use swivel sockets or something like that? Breaking the 3/8-16 bolts loose that had been torque wrench tightened was tough with a wrench, then just removing them was also very difficult.

You need to know your flywheel thickness to set your pivot ball height. The baseline of a 4.750" pivot ball height only works if you have a flywheel thickness of .950"

Is the ball stud an adjustable one? If not, you may want to look into getting an ajustable one. What I did was get it close, and plan on taking it in to a transmission shop to fine tune it, and the adjustable ball stud may be easier to fine tune it.

What was the distance with the original ball stud you had in there? I am just curious to see how far or what the difference was between them. I would double check that clutch fork too, just to make sure while you have it all apart.

I have not had to remove my bolts to the scatter shield with the motor in the car...I think that if I have to do that, I may as well pull the motor out a bit to get at them better.

My flywheel measures 1.100" at the gear-teeth outer diameter area. Is that the proper place to measure it? That is one part that is still firmly attached and I don't want to take it off too.
The ball stud is not adjustable, is GM part number 3790556, and measures 1.780" compared to the stud that I removed that measures 1.480".
The Hays clutch is .300 thick, and the pressure plate is a borg & beck design.
I am looking at buying one of the ratchet extensions that have the pivot end. Perhaps that will allow me to reach the bolts from below.
I don't believe you can adjust a ball stud once the transmission is back in.
If I had an engine hoist I would consider pulling the engine to finish this job, but that would mean removing the headers among other things. The hoist is one more tool on my wish list.

My flywheel measures 1.100" at the gear-teeth outer diameter area. Is that the proper place to measure it? That is one part that is still firmly attached and I don't want to take it off too.


Place your flywheel on a flat and smooth table with the pressure plate surface side down. Measure through one of the crankshaft mounting bolt holes for the proper flywheel thickness.

How important is this to know? I really don't want to also remove the flywheel, if it is not necessary, but I could.
Jody, thank you for jumping in here.

How important is this to know? I really don't want to also remove the flywheel, if it is not necessary, but I could.
Jody, thank you for jumping in here.

It is VERY important! I can't give you your exact pivot ball height without it.

OK, will do, but it may take me a few days to get back under the car.
One question though: I am going to replace the pilot bearing. Should I use the bronze bearing, or the needle bearing?

Again, thanks for your help.

This evening, after eating a bowl of my wife's veggie soup, I crawled back under the car. The flywheel measures .897" thick from the face to the mounting flange. Considering this, what length of pivot ball should I have?
Also, another debate: Bronze or roller bearing for the pilot bearing?

Like mentioned before, You have to have 4.750 " adjustable ball height from the back of the block to that ball stud flat on the ball head. You have to begin there.. If you run a block saver plate , you have to factor that in also. My Lakewood plate is .145 so that could be a guideline but you need to be spot on on these things or you will be off.
Personal experiance,, I had too many problems with roller tip pilot bearings,, even the one from GM for diesel trucks. I use a new GM bronze everytime I have a chance to pull the old one. And don't drive it in all the way,, should have a lip hanging out.
And you are correct about not being able to adjust ball with trans in place but IF you have the room, some transmissions will allow you to rotate the transmission on bell housing face to reset adjustment , but thats IF you have the room and IF the trans shifter will allow you to do that,,, Its such a PIA to do it this way,, Just pull the trans and get the measurments correct once and for all.

The flywheel measures .897" thick from the face to the mounting flange. Considering this, what length of pivot ball should I have?
Also, another debate: Bronze or roller bearing for the pilot bearing?

What is the thickness of your block saver plate?

You will need to get a Mr. Gasket #3855 adjustable pivot ball.

I agree about using the bronze bushing in your set-up.

We are almost there!

My block saver plate measures .126". What does that calculate for the proper pivot ball length?

My block saver plate measures .126". What does that calculate for the proper pivot ball length?

With your flywheel thickness of .897" and your block saver plate thickness of .126", your pivot ball height will be 4.571"

Mcleod manufactures an adjustable height throw out bearing to do the same thing as the adjustable pivot ball.

With your flywheel thickness of .897" and your block saver plate thickness of .126", your pivot ball height will be 4.571"


Just so everyone knows how you came up with the number:

4.750 (Target height from top of pivot ball to block)
- .126 (Block plate thickness)
4.624
- .053 (Difference between stock flywheel thickness and yours)
4.571"

Mike

Excellent info. With the mid-80's GM pivot ball (GM part number 3790556, and measuring 1.780" long) plus .084" of spacers under the head, I am now measuring 4.557" from the face of the bellhousing to the pivot ball. The head is still slightly below the bellhousing surface so it won't interfere with the transmission fit. I don't know what the tolerance is, but I don't believe the difference of .014" warrants further delays while I wait on the delivery of an adjustable pivot ball.
This did give me the opportunity to change out the pilot bearing and I will use bronze bearing. I also checked the concentricity of the bellhousing and found it to be off center by only .0045.
With my new 9/16" swivel socket to tighten the bellhousing bolts I hope to get this thing assembled tomorrow morning. If the swivel socket works, it will be the best $7 that I ever spent.
This has been quite a learning experience for me and I thank everyone who has contributed.

So this lesson did not convince you to install an adjustable pivot ball?

So this lesson did not convince you to install an adjustable pivot ball?

My logic is that I am within .014 of the target dimension with a solid pivot ball that won’t come loose with a locknut backing off, or something like that. Also, later when I again resurface the flywheel, I should be even closer to target. The only damaging thing my pivot ball can do is slightly back out of the bell housing, and then it would quickly bump into the transmission.

My pivot ball measures 1.780, but subtract the .085 spacer, it gives me an effective length of 1.695. My current assembly measures 4.557 from the bellhousing face to the pivot ball, compared to the 4.571 target dimension.

The adjustable pivot ball has a length range of 1.437 to 1.687. Extended to the longest length, where it would be the weakest, I would then have the bellhousing face to the pivot ball distance of 4.568.

I believe I have a stronger assembly that is very likely within factory tolerances.

This morning I reassembled everything. I just need to tighten the crossmember bolts, adjust the clutch linkage, connect the drive shaft, and a few other things like that.

Again, thank you to everyone for the help.

I have fought this same problem on my 67 SS convert. for the past 3 years. I have cahnged TO bearings and parts and also used the adjustable pivot.
When I bought the car it had a stock clutch with a scattersheild,the clutch pedal had to be at the floor or all the way out to work, the geometry was way off.
I changed the engine out and installed a center force clutch with all there parts, and a Lakewood TO arm, same problem and the firewall was custom clearanced by a previous owner with some large hammer.
I finally put the longer TO bearing in it and it was better but not correct.
The next thing I did was take the scattersheild off and put a stock GM bellhousing on it and the long TO bearing, it still was not correct, clutch pedal had to travel too far to operate the clutch.
I was at a loss until I found this Forum and this topic, I went and looked at the part# on the lakewood and the TO arm that was in the car when I bought it, they were the same but not the correct "632 arm" that was suggested in this topic as correct.
I went to the local GM dealer and ordered a 632 arm and long pivot for a 85 truck,which was very close to the correct install height with my Hays flywheel and block saver plate, installed this with the short TO bearing and the scattersheild, reconstructed the firewall as factory and it fit and cleared just like it should.
The clutch finally feels like it should, I know now the geometry is correct and working right.
I have several corvetts with standards in them and have never had such a time with the clutch, I was almost at the piont of putting a auto in and cut my loss.

I thank all the posts on this, It has made it enjoyable to have a stick in the camaro again.

I thank all the posts on this, It has made it enjoyable to have a stick in the camaro again.

Woo hoo....another stick shift car saved! Welcome to the forum skid.

I thought I would post the results of my clutch fork problem after reading skid marks results A friend of mine recomended that I run a lakewood bellhousing on my 67.The car has the 435hp edelbrock crate motor and m-21 muncie and centerforce flywheel and clutch.After installing the bellhousing[jegs clutch fork also] my car had the same problem as skids.The only way the trans would shift was to floorboard the pedal.I changed the fork to the 623 gm brand and everything works great!The trans shifts like it should.This web site has been so helpful,so much great info.here.I wish I would have read the thread before I changed everything over.
Daryl

OK, well... add me to the list.. CF billet FW, CF Dual Friction, Lakewood, jegs heavy fork... It hit my freshly painted firewall.... Where can I grab a 632 fork at a bargain??... The local chevy guy said 56 bucks....

BBC, muncie, 9"

If you're not in a big hurry, here: http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=3892632

Mike

Wow, 28 bucks!.. Thanks Mike!...

OK, quick update... I used the P/N's that SkidMark recomended and the GM vendor that Mike68RS recomended. Everything worked out perfect, I yanked the motor/tranny (no front clip) and the 632 fork ( P/N 3892632) and the taller 1985 truck ( I'm sure others also) pivot stud (P/N 15592268) worked out great. This combo (67', BBC,CF billet FW, CF DF, scatter shield/block plate, Muncie, 632 fork, 85' truck pivot) cut my free play in half ( from the jegs heavy fork and lakewood adj. pivot) and the clutch feels perfect. The total including shipping door to door was only 47 bucks! This Camaros.net community really works great! Thanks to everyone for thier help!...

OK, time to rehash a subject that's already 6 pages long and counting. I've got the same problem some of you others had and I'm looking for some info. First some background - I've got a 67 coupe with a '69 small block engine in it. I've got a Lakewood blow-proof bell housing and a Center Force clutch (part #CFT 361675) along with the recommended N1716 throw-out bearing. I THINK I have a stock GM clutch fork in it (can't see or feel any numbers stamped on it, but it's kind of hard to access right now as everything is installed in the car.) I've got the appropriate amount of space between the back of the motor and the firewall, so I'm comfortable that the motor mounts are not the issue. I'm also using a GM pivot ball, although I have an adjustable one standing by just in case. I intend to order the 3892632 fork to make sure I have the right one. I know I'm going to have to pull the tranny to get at the fork, but I'm REALLY hoping I dont' have to remove the bellhousing, clutch etc. only to find the spacing I have now is correct.

A lot of what I have read talks about the distance needed between the back of the block and the tip of the pivot ball. I'm going to turn this around and ask the same question coming from a different angle. Is it not possible to also use the measurement from the inside face (or outside) of the bell housing to the tip of the pivot ball. I'm kind of assuming that GM small blocks being a standard size, and presuming the Lakewood bellhousings are also a uniform size, that no matter whether you are measuring from the back of the block to the tip of the ball or from the back of the bell housing to the tip of the ball, that tip has got to be in the same relative location. If this is true, does anyone know what the distance needs to be if measuring from the bellhousing forward? As always, thanks for any and all responses.

Yes, 4.750" is the measurment that the Mr Gasket adjustable recommends. But you have the factor in the block saver plate (--Minus) if you run one. This is the way I did mine. An you measure from the flat face on the ball stud, if it has one.

4.75" would be from the block face tho, right?
I think he's asking for a number to measure from the back of the bell.
I would imagine if you measure the total depth of the bell, including the block plate, and subtract 4.75" that would be it?

Yes, Jim. That is what I am asking. I was always terrible at math - obviously I still am. What you said makes sense. According to the Lakewood web site, the depth of the bellhousing I have, including the block plate is 6.45 inches. That means the tip of the pivot ball needs to fall 1.7 inches from the outside face of the transmission side of the bellhousing, correct?