snb73

I remember reading a post that explained which pivot ball to use. ( long or short ) I think the stock one is the shorter of the two. I am replacing the clutch and now is the time to do it. Does anyone know the part number?

Thanks, Steve.

Fevre

I bought a Lakewood adj pivot stud and used JB weld to secure the head portion of the pivot stud to the base. Don't use it on the base or you will not be able to get it out of the bellhousing. Reason for the JB Weld is a few members have stated the nut comes undone after a while allowing the head portion to move in or out. I'll post a pic of the 3 peices to get you a better idea.


[Modified by Fevre, 10:52 AM 7/16/2003]

Fevre

As promised:



Link:

http://store.summitracing.com/partde...rt=LAK%2D15501


[Modified by Fevre, 10:54 AM 7/16/2003]

Marks69BB

I'm really interested in the dimension you set the adjustable ball at. Do you have or remember the measurement from the inside surface of the bellhousing to the top of the ball?

Fevre

I just did the old 'this should be good method'. It is great when cold but I keep getting binding/grinding problems when it gets warm/hot. It is much better since I switched to the adj pivot stud but it is still irratating as hell to be so smooth when cold and not when hot. Personally if I where going to try any type of measure I would look at the distance the fork travels from the time the throw out bearing touches the pp forks till the clutch fully releases then split the diff. I would think you would want the fork to be parallel to the flywheel/clutch half way threw its travel distance but I am a numbers guy not an eng. Of course an eng put the fuse panel where only a midget can reach it. :)

PRNDL

You definitely want the long GM stud as opposed to the short GM stud, but some have said the long is too long, so you are probably better off with the Lakewood adjustable. I have one of each! :D The GM part# is 3790556, but unfortunately I am not sure if that # is for the long or short stud.. All the dimensions are on the orange sheet that comes with the Centerforce clutch. I have a picture of it that another member sent me. Can retrieve it if you need it. (but it may take a while) MJ

Jughead

Here's a post from Steve a while back: http://forums.corvetteforum.com/zerothread?id=462630

Clink69

I just did this job two weeks ago. The measurement of the ball stud is not as important as the measurement of the ball stud tip to the far side of the engine plate. This should be exactly 4.75" and WILL require an adjustable Ball stud. (use JB weld on nut or Red loctite). The engine plate is 1/8" or .125 ". so if you eye up the edge of the bell housing (part that mount to engine) with a ruler sitting on the tip of the ball stud that distance should be 4.625". this is the imnportant distance. Do it wrong (as the guy that did mine last time did) and the geometry will be off allowing the TO to hit the PP fingers off even. the instructions included with the CF DF PP and clutch describe this in detail. Also all this takes into account that you are using the CF TO bearing, which is 1 3/8" I think. I can dig up the Part # if you don't have it.. Mine came out perfect, soo smooth shifting now, NO chatter...
this is all considering I used a Lakewood bell housing. If you are not then the 4.75" should be to the edge of the Bell housing itself...

Also The Clutch fork rod will now need to be longer. I got a longer one (1.5" ) and it worked perfectly. The last mechanic tried to make up this distance with a longer TO and pushing the Ball stub longer, Big Mistake.. Throws the geometry way off and the TO hits the PP fingers at an angle...
Got the longer Rod from Tony at Tony's corvette...

If you have any ?? drop me an IM and I be glad to advise...




[Modified by Clink69, 8:42 PM 7/16/2003]

71roadster

I used that adjustable thing and after just a few thousand miles the lock nut had cracked allowing the ball to move. I replace it with a full sized hardened nut and used lots of locktite when I put it back together.


Chris

snb73

What is the part number for the stock "longer" pivot ball?.

I also purchased a stock throw out bearing, will this work. Or should I just get a new CF throwout bearing, and an adjustable pivot ball?

Thank you all for the help, Steve.


[Modified by snb73, 8:04 AM 7/17/2003]


[Modified by snb73, 8:05 AM 7/17/2003]

Clink69

You do that and it will chatter and wearout prematurely. This is what was in mine from my prior CF DF... Use the CF TO and the Adj Ball stud. Order online from Summit or Jegs.

snb73

How long should the ball be? I have the stock trans with the stock bell housing. Steve.

Fevre

It is not the length of the stud but the distance between the throw out bearing face and flywheel that you need to be concerned with. There are variables such as flywheel thickness, fork wear, throw out bearing thickness etc that will factor into your measurement so the adj pivot stud is the best thing to get.


[Modified by Fevre, 1:23 PM 7/18/2003]