I know, I know, there are a lot of people here running centerforce clutches and love them. I was one of them. I ran this clutch (centerforce 2) in my old engine/tranny without any problems what so ever. But when I put in the 383 and the TKO it just stopped working right. I had to put the pedal all the way to the floor to get a clean shift and that was with pretty much zero clearance on the throwout bearing. I pulled it out a while back and carefully measured everything. Centerforce tech support gave me a measurement for 'uninstalled' height I exceeded by .5" and so they said send it back. They checked it out (for free) and assured me everything was ok - but never clarified the discrepency in the uninstalled height. I very carefully reassembled everything and it was just as bad. Centerforce kept insisting my linkage was wrong, etc, etc. But come on, clutches are not that tricky, and my linkage has nearly 0 slop. So I finally got sick of missing shifts and ordered a Stage 2 clutch from Spec. Put it in last weekend and ALL of my problems have disappeared. Not only can I shift with the pedal only 1/3 down, but the engagement is much more positive. And now the TKO shifts like it should - I suspect the old clutch was never fully disengaging (and yes, I carefully aligned the bellhousing). And most importantly, a SEVERE vibration that I had not attributed to the clutch has gone completely away. This vibration actually rattled the transmission bolts loose - as well as a dozen other bolts! The wear marks on the clutch do not appear to be off center so I have no obvious explanation as to what was causing the vibration, I am just happy it is gone. The vibration really put a damper on my enjoyment of the new engine/tranny and now it is smooth as glass! Hopefully this will move me up a notch at the next autocross.

I can't fault Centerforce for their service and the clutch did run 5000 miles trouble free and I can't explain what exactly caused the problems, but I can say I changed the clutch and 3 major problems disappeared.

 

I had a centerforce in my 93 z. It never disegaged fully once you got it nice and warm. They charge so much and the darn thing didn't even work right. In the end it lasted a decent length of time but it took the transmission with it. I had to rebuild the tranmssion because so many of the syncros were destroyed, mostly 1st and reverse. Centerforce won't even talk to a guy calling about an fbody clutch last I checked. They claim its everything from the hydraulic system to operator error, but with so many people having issues I just can't see that there could be that many people that can't get one successful install working.

After the clutch went out I rebuilt the transmission and installed a Mcloed clutch disc with an SLP pressure plate, and all has worked beautifully. Cost was about half of the centerforce dual friction clutch too.

 

McLeod

 

It's been a while but doesn't this installation require a taller / Adjustable pivot ball in the bellhousing to correct this problem?

I believe it was .5 taller than standard to allow proper alignment. jim

 

correct---

 

I am about to install a centerforce dual friction in a 1969 427. We someone detail exactly what i need to do to prevent this problem from repeating itself in my car? I am unclear where you would get this taller pivot ball.

Scott

 

http://store.summitracing.com/defaul...=egnsearch.asp

The proper dimensions and lots of warnings are included in the paperwork that accompanies the clutch.



My Centerforce works fine.

 

I had similar problems and it turned out my motor mounts were shot and once they were replaced the shift linkage could then be reset. If your motor mounts are old, try replacing them and then double check your linkage.

 

I'm running a Center Force Dual friction clutch in my 69 behind a 509 cubc inch big block and love it. Very smooth and a nice feel to the pedal. I'm also running a Lakewood scatter shield with and adjustable pivot ball. I just followed the instructions for indexing the bell housing and setting the pivot ball hieght correctly and have not a single problem.

 

I wish I had a scanner to scan in the sheet from my CenterForce II clutch set. It gives the dimensions etc. for set-up. It does say aftermarket bellhousings on Chevrolet engines must use the taller pivot ball.

I think Centerforce could have been a little better at explaining the procedure and that it would be good insurance to check and align all belhousings and adjust the setting of the pivot ball to spec. Jim

 

Centerforce has lots of "issues" in their instructions on installation of their clutches. I use the "short" GM fork pivot and STAY ON TOP of my pedal freeplay for the 1st 1500-3000 miles. After about 3K miles disc wear seems to "calm down" and adjustment is required at fewer intervals. The Centerforce clutches need MORE freeplay than a std clutch because the centrifugal weights will cause the pressure plat fingers to bend rearward at high RPMs and if you unload the disc you'll quickly burn it up. I really DON'T like the Dual Friction discs and have been running McCleod Kevlar discs in my last few clutch replacements with better success than the CFII set-up. I like the pressure plate but not the discs! and they have the WORST installation instructions and customer service!

 

Yes, I am aware of the installation instructions and very carefully followed them. The problem with those instructions is that they spec from the back of the block, not the surface of the flywheel. So different thickness flywheels really change the setup. I was running a hays billet and went to a factory flywheel (3/16" installed difference) in the 383. I also tried many settings on my adjustable pivot ball. I just could not make it work. And I was using the centerforce throwout bearing, but there really is no difference between theirs and factory. I just gave up and my problems went away.

About the adjustable pivot ball, I highly recommend replacing the skinny jam nut with a regular sized nut. My original jam nut cracked after very little use. Also, I slotted the end of the stud so that I could loosen the jam nut and adjust the height with everything installed. Had to 'clearance' the tranny case just a bit to be able to get a skinny screwdriver in there. Beats pulling everything out to make minor adjustments to the jam nut. Lastly, loktite the heck out of that thing, especially the part that screws into the bellhousing.

One thing on the lakewood scattersheild - I did not like that flange hanging down so I cut off the bottom part of the flange. It doesn't affect the safety aspect and I gives me peace of mind that the bell housing is not going to bottom out and rip the entire car to pieces.

Chris

 

Try to communicate to Centerforce that the most "critical dimension" is not on their instructions. I tried to talk with them several times on the dimension from the Flywheel to the pivot ball being so screwed up in their instructions that Einstein couldn't figure it out. Centerforce's reply was that I didn't know what I was talking about (I have a College degree in Design Drafting and used to work for the US Department of Energy drafting Thermo-Nuclear devices so, I think I am qualified to critque a missing critical dimension on a drawing.) I have a "love-hate" relationship with this product but, the centrifugal weights are their unique product and I do like the technology.

 

Why not measure the thickness that the flywheel protrudes beyond the mounting flange on the block? I did. Seemed like the ONLY way to get the proper setup on the pivot...

 

Chris, I was in no way implying that you were lacking in skill,(* I know better) just that you either didn't have or they did not supply the correct information about the setting of the pivot ball to accommodate clutch fork travel.

And after your last reply I'm not sure if the statement I made above is even true. Did you set this up to all of Centerforces specifications? and if so are there other issues? Now I'm worried about putting mine in. Are the issues all about the linkage adjustment and pivot ball or the Clutch & Pressure Plate itself? Jim

 

I tried the adjustable pivot ball with my Dual Friction, and it screwed everything up. I then recalculated the surface of the flywheel to the pivot ball, and accommodated by using a short style GM pivot ball with a 0.990" Hays Billet Steel fly wheel. Clutch works fine, with the stock linkage, however; I am getting an adjustable clutch rod for the fork to give me better adjustments now that the clutch is fully broken in. With that said, yes they are a PITA, and I probably would not install one again.

 

Ditto somewhat. I used the adjustable with the JB weld install. Fixed the problems I had, but I wouldn't ever get a Centerforce DF clutch again....too much in and out and no go time!

 

With the new clutch I did not change the linkage or the pivot ball height. My feeling is that the diaghram somehow became 'soft'. I tried this setup with the linkage setup the way centerforce said to (making adjustments for flywheel thickness) and half a dozen other ways, including with the pivot ball extended as far as possible which allows for the absolute maximum swing at the end of the clutch fork. When I first pulled it and tried to figure out the problem, Centerforce kept insinuating that I was not measuring the installed [correction to my earlier statement of uninstalled]height correctly and maybe I wasn't, but the directions for measuring were pretty clear. Bolt it to a flywheel and measure the height of the diaghram from the flywheel surface. And none of this explains why the vibration went away. For me that was the far more problematic issue.

I mainly posted because I am so d**m happy
the problems went away and to warn others about the POTENTIAL for problems. As I said, this clutch worked great for 1-2 years. But the vibration, the difficulty to shift, and having to mash the clutch into the floor were really dampening my enjoyment of the car and especially the new motor/tranny [$$$] combo.

And I certainly agree that Centerforce can do a much better job with their directions. I, like many here, am an engineer and spend much of my time writing technical documents. Their directions seem intended to me, in my paranoia, to allow them wiggle room to blame the installer if there are mysterious problems such as mine.

Chris.

 

How do you measure the uninstalled height and what should it be? I will be installing a CFII this weekend or early next week.

Thanks,