Why is my Clutch Trying To Explode?

**Vyperion** · 08-11-2012, 12:25 AM

Hey, so I undertook a slave cylinder/clutch replacement this last week, and once it was all back together it's trying to explode.

I took everything down to the pilot bearing apart, and installed a new: Pilot Bearing, (Resurfaced) Flywheel, CCI Stage 2 Clutch Disc and Pressure Plate. It took me a while to get the transmission lined up (several days). Once the car was sewn back together, I started it up and gave it a test 'go' in the driveway to ensure proper operation and shim size.

I revved it, and it shook a bit past 2000 RPM. I tried to engage the clutch, and it began to engage about 50% of the way up. About 75% of the way up, the car started shaking like it was going to destroy itself or blow something out the bottom. I never put it all the way to 100%.

So I'm terrified that I have messed something up royally. The obvious problems with such shaking is a) effed up the pilot bearing (shaking in 'gear'), or b) flywheel bad (shaking in neutral).

After total disassembly, the flywheel seems fine, except for a tiny 'chunk' missing (In the 1st photo, around the middle of the 9 o'clock area), which may have been before the refinishing, not sure. The pilot bearing seems fine. The clutch and clutch mating surfaces (pressure plate surface, flywheel surface) all share a small (1/4") contact patch around the area which doesn't exist across the rest of the surface. I know it won't be perfectly even as it wears in, but this thing seems like I'm going to explode my car!

So can anyone tell me what's wrong, or at least where to look? I've included photos of the Tranny spline for 'grease level' reference. Too little? Could too little grease be causing problem with the Pilot Bearing/Etc? Could my Pressure plate have been on unevenly? How important is it that all of the Plate's spring 'teeth' are even? Is that one small piece missing from the Flywheel a big deal? Should I be worried about the small (1/4") contact patch across the assembly? On the clutch disc, the non-flat part (in this case, shiny coppery side) should be facing towards the transmission, right? Might something else be wrong?

**Vyperion** · 08-12-2012, 09:45 PM

Something that I have seen come up a few times is reference to proper 'indexing' for flywheel and pressure plate...can anyone inform me as to what this means/how to do it, and if it would matter for vibration?

**35th-ANV-SS** · 08-12-2012, 09:54 PM

Copy and paste the IMG code here. Your pics are not showing.

**SuperSSguy** · 08-12-2012, 11:05 PM

I had my clutch done a while back with a Centerforce II and after i picked it up i had a terrible shake at around 2000-2200-ish rpms my passenger seat and shift knob were doin a dance..needless to say i was pissed of..anyway the shop gave me the run around and i mistakenly didnt fight them on it/took it to another shop were the guy told me he didnt like Centerforce clutches because of that problem-he pulled it for me and had the assembly balanced? It worked fine -no shakes anymore? I learned later on that if the installer doesnt line up the ''pins''? ( not sure if it was pins or whatever but..),,,basically all the parts have to be aligned correctly as shipped. So i dont know to this day if 1/ ...the first shop did a shitty job.... 2/if the second shop really balanced the flywheel etc or did they just re-assemble it correctly (and ripped me off) 3/If Centerforce clutches have that problem? ..I do know that next time ill go with a different brand Spec maybe?......anyway im guessing its not aligned properly.

**Vyperion** · 08-12-2012, 11:30 PM

My new clutch is a competition Stage 2.5, so I'm afraid I can't speak for Centerforce. Seems like at least the index hole was off, so that may be contributing. Also, I reused the bolts (didn't know the nature of TTY bolts), so I'll be replacing those.

Is it necessary to have the whole assembly (flywheel, clutch disc, pressure plate) balanced? Or is that overkill?

https://www.dropbox.com/s/6x8e1tbsqpeu6hn/P1020337.JPG
https://www.dropbox.com/s/2vw7ukizabcdix5/P1020346.jpg
https://www.dropbox.com/s/cno3u7ug5tfs0u1/P1020348.JPG
https://www.dropbox.com/s/vwme3k6b8ovwwni/P1020358.JPG
https://www.dropbox.com/s/g5galf5jceuw69u/P1020359.JPG

**SuperSSguy** · 08-14-2012, 12:11 AM

^As far as i know from past clutch jobs(on past non f-body cars i had) i dont remember any of them needing what the last one on my SS did....so? Other members should be able to answer that? Like i said as far as i know the whole assembly has to be put on a certain way...i think?

**35th-ANV-SS** · 08-14-2012, 08:21 PM

I would guess something wasn't aligned properly and while spinning the distribution of uneven weight is what is causing the horrible vibration. Not too sure on the missing piece and that throwing off the balance. I would think that would throw it off though.

Also, if your pedal is engaging that high, you need to install a thinner shim. The clutch pedal should engage right off the floor on a new install.

Here is some more install info: http://www.installuniversity.com./ls1/install-documents/mcleod-clutch-installation/mcleod-clutch-installation.html

**SuperSSguy** · 08-14-2012, 10:57 PM

^^ When i got my CF clutch from Summit i looked at it and i think i do remember that it said specifically that it had to remain and be installed in a particular order i think it had markings or arrows indicating which way was which so???? Thats why i said i didnt know if my first shop screwed up or what?...all i know is on the money end,,i got screwed royally!

**SuperSSguy** · 08-14-2012, 10:58 PM

Originally Posted by 35th-ANV-SS

I would guess something wasn't aligned properly and while spinning the distribution of uneven weight is what is causing the horrible vibration. Not too sure on the missing piece and that throwing off the balance. I would think that would throw it off though.

Also, if your pedal is engaging that high, you need to install a thinner shim. The clutch pedal should engage right off the floor on a new install.

Here is some more install info: InstallUniversity.com LSX, Lexus, Mercedes-Benz, and Apple

Jon, what clutch you runnin?......any issues like ours?

**pajeff02** · 08-15-2012, 02:34 AM

What Jon said. Plus a couple of things... almost all new clutches will have some degree of chatter until they work in a bit. The stock flywheels have a taper and the service manual strongly recommends against resurfacing them. Did you evenly tighten the clutch by working around the bolts in a crosswise fashion a bit at a time? If not, they can be warped during the installation process. How about centering the pressure plate? If you weren't lined up fairly well before sliding the transmission home, they can be bent. Did you degrease the flywheel good before installation? Not sure what style clutch that is, but the last one I installed (in an Olds) had plastic spacers in the fingers that had to be taken out before installation. You can dial in the center on your bell to ensure concentricity using a magnetic base and a dial indicator. Good luck!

**35th-ANV-SS** · 08-15-2012, 07:28 PM

I have been running a Spec Stage 3+ rated for 850 lb-ft of torque for about 4 years now. Zero issues. Clutch pedal after the install engaged right off the floor and after some miles and break-in it started engaging about 1/3 of the way up. Maybe a tad higher. I have about 15,000 HARD miles on that clutch now and it's solid.

**SuperSSguy** · 08-15-2012, 11:08 PM

^^ Maybe that will be my next clutch?...The CF-dual friction i have is good it doesnt chatter and grabs great but i had too much trouble with the balancing.

***SMWS6TA*** · 08-16-2012, 08:48 AM

Originally Posted by pajeff02

What Jon said. Plus a couple of things... almost all new clutches will have some degree of chatter until they work in a bit. The stock flywheels have a taper and the service manual strongly recommends against resurfacing them. Did you evenly tighten the clutch by working around the bolts in a crosswise fashion a bit at a time? If not, they can be warped during the installation process. How about centering the pressure plate? If you weren't lined up fairly well before sliding the transmission home, they can be bent. Did you degrease the flywheel good before installation? Not sure what style clutch that is, but the last one I installed (in an Olds) had plastic spacers in the fingers that had to be taken out before installation. You can dial in the center on your bell to ensure concentrically using a magnetic base and a dial indicator. Good luck!

In addition to this^^ there is 2 torque specs done in 2 passes. It's been a while so I won't miss quote the exact ft lbs. The clutch instructions should have them.