Clutch recommendation needed for L88/454 10.5"

Before you get too crazy put the car in the air and take off the drive shaft. With it in gear have someone press the pedal. If you can turn the output shatf with the yoke you are home. If not you are stuck and need to get the bigger throw out bearing. When I converted to hydraulic I went through partial release hell. This was the only way to be sure. Do not leave everything connected and try to spin the tires. You have so much leverage that it can overcome a partial release. Easy check.
 
quick mini-update....

I took the clutch assembly to Horse Power Sales of Pompano (forum sponsor of the Corvette Drag Racing Challenge Series and widely known for producing many amazingly fast C4~C6 vettes). I wanted a totally independent opinion on what was going on since my knowledge of clutches is non-existent. The mechanic there explained to me some of the basics about how it works and then showed me the wear patterns on the pressure plate side of the disk vs. the fly wheel side. The clutch disk is almost totally worn down on the pressure plate side so he believe the clutch was always dragging on the pressure plate side and not the other side eliminating any problems with the flywheel. He thinks that either the pressure plate is defective not allowing for enough clearance or the pressure plate was not installed correctly but found it hard to believe due to the severe wear on the disk & uneven burn marks that it would be from an incorrect install like torquing down the pressure plate bolts wrong. He did not believe it was from an incorrectly installed TO bearing.

I am fast becoming a clutch expert. The mechanic that originally did the install will see it tomorrow morning and then I will be sending off the clutch assembly tomorrow afternoon to CF to get their final opinion.

Lastly...they told me of a brand new Z06 they had installed a Spec Stage 3 in and when the guy did a high rpm shift the clutch disk blew off and literally went right through the dash. They have had 3 newly installed Spec Stage 3 clutches fail this year and now will no longer install them. They said the guys insurance company (StateFarm) hired an indpendent expert to observe the damages as they were going after them since they installed it and also GM and Spec. When the expert guy saw that the clutch disk had literally spun off and ripped right through the dash there was no more question that it was a defective part. This all came about as I now have a Spec Stage 3 installed that I am now having different problems that I never had before I was explaining to them. I can't believe my luck...looks like I got two bad clutches back-to-back.
 
Another arguement for a scatter shield type bellhousing. Ask Big Daddy Don.
 
I got some great news from the guys at Centerforce today!!! I am getting a complete new clutch assembly from them. I sent them off all my parts, etc. for evaluation and possible warranty claim if it was due to defective parts.

They discovered some of the fingers on the pressure plate varied in height which could have resulted in the uneven wear. Also, the wear marks of the TO bearing are close to center, however, the geometery may be slightly off not allow full clutch release whcih could also have contributed to the problem.

I am a very happy person :D getting a new clutch assembly since the Spec stage 3 clutch that I replaced this with is slipping and giving me vibration problems. While it does suck to have this happen in the first place going through 2 different clutches and paying twice for a clutch install it is great to have a company that still stands behind the products they sell. They could have easily said it was some sort of installation problem and then I would have been screwed as there is not much I could do once it got to a finger pointing blame game between the mechanic and the parts especially since I supplied the parts.
 
At least they are supplying a new clutch. Unfortunately, you have to pay again to have it installed:bomb: Or is the shop going to cut you some kind of deal?
 
The mechanic that did the first install did say if it was not his fault he would cut me a deal on the labor. Hell...I have spent probably close to $8K with them over the past 4 years and always paid bill on time so hopefully they will cut me some slack.
 
I finally have Kaoss (Killer) back in my hands again. I picked it up this morning...ran 3 miles down the road to get tires balanced and alignment for good measures and then vroom vroom for about 40 mins down I-95 from Pompano to Miami this morning listening to the sweet sound of sidepipes and I almost forgot how much fun the car is to drive and fast too.

"Crossing fingers" and "knocking on wood" thus far all good. I can't hammer the throttle yet for another 450 miles to let the clutch break-in properly so that sucks but I did manage to stretch her legs up to 120mph running in 5th gear at about 80% throttle. There were no more weird driveline vibration issues like before with the Spec Stage 3 clutch as the stick shift was steady & smooth. It cost a pretty penny to have these guys do the install, Horse Power Sales, but in speaking with the mechanic he did blueprint the entire install with runout of the flywheel after it was bolted up, bellhousing, air-gap, etc. and had all solid "no BS" answers. He found a few interesting things not correctly installed like the new needle pilot bearing was installed backwards, the bellhousing apparently needed different dowel pins to better center it on the block, and he had to resend the flywheel back because after the first re-surfacing job it was something like 0.002" out of spec in one area from the machine shop. The clutch pedal now is a lot stiffer than the 3 clutches that I had in there before and also stiffer than my centerforce clutch that was in my previous red 69 vette. It also has a more consistent stiff feel all the way through depressing the clutch as before you would kind of feel an initial stiffness and then it would ease up as you pushed further but this one seems to be stiff throughout the operation. Ugghhh!!! I just hope it all holds together for at least the next 20K miles. If not then I am going with a 200R4 and be done with this clutch maddness. I must say that Centerforce was very professional and customer friendly testing out the clutch to see what/if anything was a manufacturer defect and then they sent me a complete new setup but before doing so they said they spec'd out the assembly to make sure all was perfect so I would not have any problems.

Also I had a drag racing modification done to the trans since we were at the "while I am at it" junction. I sent the trans to a guy named Bob @ Performance Transmission 217-935-5352 in Clinton, IL. The main reason I sent it to him was to make sure the trans was all healthy since I was having clutch problems I wanted to eliminate any other issues and inaddition to him finding a 5th gear spacer had broken free and started chewing up 4th gear where it got wedged in the casing he "lightened/drilled out" 2nd & 3rd gear taking out almost 2lbs of material between the two gears. The idea is that the gears have two much rotating mass for the synchro's to stop them and allow smooth high rpm shifts from 6,000+rpms. The trans feels a bith notchy due to the new parts installed and setup but Bob said it should break-in nicely resulting in very smooth operation and quicker high rpm shifts after several hundred miles. Thus far it feels great...but as with the clutch time will tell after everything is broken in properly, etc. He races what he builds and is passionate about his work and the cost and turnaround time was very reasonable. Taking out almost 2lbs is some serious weight reduction but he assured me that the gears would still hold the about 550 crank HP I am putting out.

I have a few misc items to address like installing a new tach (already got it) and a full detailing and then check everything over now that the car is in my hands to make sure every last nut & bolt are secured correctly, etc. But by this Sunday I think I will finally be able to say everything is working 100% correctly and be able to just drive and enjoy cruising around town and to dinner putting on another 450 miles as quickly as possible so I can get Kaoss to the drag strip for some 1/4 mile fun and also report back in about a month how everything is doing after the 500 mile break-in period.

btw...the mechanic could not find anything wrong with the spec clutch that was in there and why it would not hold the power even at only 80% throttle (it was slipping). It looks brand new (has about 700 miles on it) and he said there were not any unusual wear marks on the flywheel wheel. I am not sure what I am going to do with a $700 spec stage 3 clutch and the lightweight pressure plate. Maybe I will eBay it and if it sells for maybe $50 vs. $700 for a new setup somebody will have better luck with it than I did.
 
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