The service manager is our nephew and he makes sure our cars are done correctly.

But I'll be sure to mention it to him. He's a car nut as well so I'm pretty sure he'll know what needs to be done.

 

.... I've got them !

 

I am willing to bet you a dozen do-nuts he will not be familiar with the balance issue. But since he is your nephew, you stand a better chance of him not looking at you like you are crazy

Do yourself a favor; if he doesn't think you should be "concerned" with that, please KEEP your stock FW and PP after the job is done until after you have determined that you don't have new vibrations. If you end up tearing into everything again to try to "rebalance" something, your factory FW/PP combo will serve as the CORRECTLY balanced/weighted assembly for YOUR engine.

Also, if you take him for a ride to let both of you establish that your car is vibration free and smooth before you get this work done, ALSO have him sit with you in the car, with the car at rest, with the gear shift in NEUTRAL, and with the clutch pedal depressed (disengaged). Rev the car in the 3000 to 4000 range and NOTE how you (hopefully) have NO vibrations currently. This test isolates the engine/clutch assy alone and excludes any driveline parts contributing to any vibrations you may or may not have.

I am REALLY interested to hear what he says when you mention this to him. With your year car, it is actually in the service manual though, but I won't comment further on that

Good luck, and.... good luck!

 

Hey Bill,
I have confirmation the hot balance is actually still being done on the current Gen C7's. As well as the LS7s going into the Z28's. This issue won't be "going away" anytime soon. Go figure

 

SEE!!! Someone else who has been around the block and had to deal with this issue.

You would be absoluty AMAZED at how many WORLD CLASS GM CERTIFIED TECHNICIANS have ZERO CLUE on the proper GM procedure for replacing a C5 /C6 Clutch. SAD! VERY SAD!!

The advice that you are receiving is or has been written in pain and anguish. When you have a NEW vibration or your transmission will not shift without grinding after the install and your Nephew says, Its NOTHING I DID,,,,,, what recourse do you have????

Were just trying to ARM you with knowledge so that you wont have issues...

You might also ask him about taking the critical measuements between the throw out bearing and the Torque Tube and the clutch pressure plate fingers to the bell housing face to see if you need to add a SHIM between the slave and Torque tube..

Anytime that you install other than GM parts, you could change the stack up height clearance between the throw out bearing and the pressure plate fingers (AIR GAP) resulting in not being able to fully disengage the clutch and cause the car to CREEP FORWARD when your in gear and clutch fully depressed and you rev the engine to about 5000 rpm. It will also cause grinding between shifting gears.

Recovering from either one of these issues is DOING IT ALL OVER AGAIN!

PLEASE,, Let us know how you make out and if you SCHOOL the Nephew!!

 

Will do..... I'll be sure to point all these items out to him so he can put on the work order for the mechanic to see.

 

This is an AWESOME thread... who knew? well, Bill and thbwlz did...
That tech is either going to say oh yeah.. I got this. Or
Holy Crap I didn't know that!!! Should be interesting for you and the nephew... would be cool if they would let you video the process. The dealership videoed the install of the supercharger on our FJ Cruiser just because it was the first one done in our entire region and they wanted a CD for other techs... just a thought, they might educate other dealerships techs with what is proper procedure...

 

Sorry guys, I'm not burning a vacation day to hang around the dealership to video tape a clutch swap.

Our nephew (the service manager) is in his mid to late 30's and has been at the dealership for many a year. I'm pretty sure he knows what to look out for when it comes to my FRC.

AND I'm pretty sure my FRC isn't the ONLY Vette to have been there for a clutch swap.

 

The issue of bad vibrations after clutch installs is a recurrent theme around here for the obvious reason that many, I would argue most, shops either don't know or don't follow the proper match balancing procedure that will guarantee you will have the same properly balanced driveline after your install. How many dealerships or high end speed shops don't know how versus don't care? Who knows, but I'll tell you that my own experience at a VERY high end (everything from new and old classic Vettes to uber exotics like an F40), most of them haven't a clue that match balancing is the only way to assure a vibration free install. Could you gamble and probably be ok? Sure, that's your call here, of course. That said, I've seen a number of stock flywheels from C5's and C6's and almost all of them have had SOME balancing done at the factory to neutralize bad harmonics. This is not the same as "zero balancing" done by a clutch manufacturer. Zero balance is a neutral, zero balance done to the clutch assembly. That's good, fine. But it's not done to address the need in a C5/6/7 to neutralize harmonics in the drive SYSTEM. It's done as a neutral starting point for a clutch. Match balancing, considering the relatively large time and money invested in a proper clutch install, is time and money well spent. Quite a few people here, not including myself, know more than 99.99% of "certified techs" out there. Even detail oriented, conscientious techs like your relative may not know what we are dealing with here and to dismiss the advice of some of the people who've been dealing with this issue in detail for years now would be foolish. Just my opinion, of course. No harm in asking him, right? If he says it's not needed, he is wrong, period. He might be correct that YOU in your case, after the fact, don't notice the vibes or won't get bad vibes, but he can't predict that beforehand.

 

As I mentioned above.... I'll make sure to point all this out to him so he can put in the work order for the mechanic.

AND "IF" by chance there is vibration after the work is done, the car goes back in for them to fix the problem !

Simple as that !

 

His standard protocol for a clutch replacement will be to just install a new clutch assembly, FW/PP, straight out of the box. Match balancing the assembly to your stock pieces is NOT something he is going to be familiar with. That is a very strong prediction.

 

Everything you said is 100% accurate and correct

 

I gotta ask...

What PROPSHAFT couplers are you using to replace your stock pieces? OEM stock replacements? Or some aftermarket couplers? Stiffer? Solid?

 

After too much research, I came to the conclusion that unless you have insane power output, like 1,000 HP, go with OEM. Don't get "OEM equivalents" that look like OEM. They're usually just rubber, unlike the OEM which are a bonded fiber and rubber and far stronger. Poly don't hold up as well and solid aluminum is too rigid. OEM all the way.

 

This is not something you can just ask him to "put on the work order" so his techs "do the right thing". The match balance issue is something that takes a good detailed conversation. We are recommending that you MATCH BALANCE the clutch assembly. Which means having your FW/PP COMBO assy MATCH BALANCED to your stock FW/PP COMBO assy. I am 99.9% certain he won't be familiar with this. I am 99.9% certain they do not have the equipment at the dealership to do it either. They don't build engines there and they aren't a machine shop supporting engine builds. I am 99.9% certain they do not have the means to balance rotating assemblies. (NOT a tire balancer )

IF they were familiar with this issue, they might be familiar with just transferring balance weights from your stock flywheel to the new one. Well, I am also 99.99999% sure that your aftermarket Spec flywheel DOES NOT even have the 12 circumferential holes in the perimeter of the flywheel that act as receptacles for the balance weights. So you couldn't transfer weights anyway. Which isn't so bad anyway, because transferring weights is a poor way to attempt an assembly balance.
1. It doesn't take into account the variances in beginning flywheel imbalance, due to balance tolerances.
2. It completely ignores the pressure plate and their variances due to as delivered balance tolerances.

The ONLY way to ensure you have the same state of balance of your entire clutch assembly as that of your stock clutch assembly is to MATCH BALANCE the new assembly to the stock assembly. That means FW/PP together matched to original FW/PP together. That is not something that he is likely able to do at the dealership. You would need to have that done at a good machine shop that can balance rotating components (like crankshafts). And then you would need to find a shop that knows how to MATCH instead of just zeroing everything. You'd be surprised how difficult that seems to be.

Your nephew is MOST LIKELY going to recommend just installing your new clutch assy straight out of the box. And that may turn out to be JUST FINE. There is a good chance that will be fine. There is also a good chance you feel new vibrations you did not feel before. I'm sure your nephew is a very talented and awesome mechanic, but this is something almost no one is familiar with.

I sincerely hope it turns out great for you, because chasing vibrations SUCKS.

Good luck and please let us know how this turns out. Please let us know how the discussion, if there is one, goes.

 

I TOTALLY agree

The only reason I asked is because if he is not replacing with stock OEM couplings, then that will ALSO be a possible contributor of any new vibrations. People don't seem to understand that components are engineered and designed with the ENTIRE system in mind. Damping characteristics are considered along with torque carrying capability, shock damping, angular misalignment capability, etc....

So many people get aftermarket stiff or even solid couplers for their stock or near stock level HP cars and then complain about vibrations. go figure!!

 

My brother has a Pontiac Trans Am Ram Air and it needed a clutch. He is NOT able to do the repairs himself and asked me what he should do. Take it to the STEALERSHIP OR OUTSIDE SHOP?? I told him I would find a competent performance shop in Baltimore.

Well,,,,,, ,,, He took it to the GM dealer and they said they would use a better aftermarket clutch. They used a Centerforce clutch/pressure plate. Guess what?
It had significant engagement issues but, it still worked. My brother is NOT mechanically smart enough to know what they did wrong and complained to the service manager about the feel and very low peddle engagement.

He had to press the peddle all the way down to the floor to get it to disengage and it engaged just off the floor..

The service manager stated, "That was NORMAL for a high performance clutch." My brother called me and asked me what he should do?
\
So, I had to do the detailed "How the clutch was suppose to work" and explained exactly what they did wrong.
LIKE I STATED EARLIER; I armed him with knowledge to defend his complaints and argue what they need to check and explain what was causing the issue.

Long story short, the Air Gap between the throw out bearing and the pressure plate fingers was significantly incorrect due to the slight difference between the stack up height difference of the Centerforce pressure plate fingers compared to the OEM GM pressure plate finger height.

They removed the entire Centerforce clutch and pressure plate and installed all new GM Parts.
Problem solved! He is still thanking me.

They could have just shimmed his throw out bearing but, at this point they just wanted to fix it.

Bill

 

thbwlZ

SPOT ON BROTHER!! I can wait to see what the NEPHEW says about shimming the throwout bearing!

Some cars need it,,,, some don't. I installed a SPEC Duel Disk clutch. The directions and everyone stated..... INSTALL the supplied SHIM behind the throwout bearing!

So, I used the TICK procedure and actually MEASURED the air gap using their procedure and I DID NOT need the shim.

The closer I got to doing my clutch job, the more I read about the balance issues people had after installing aftermarket clutch parts.

So,, I found a hole in the wall race shop that built dirt circle track race cars and discussed the MATCH BALANCE procedure I needed with the owner. THAT WAS INTERESTING!!

As he spit the tobacco juice from his chew, he said " I was match balancing parts when you were a wet dream. LMFAO!!

He knew exactly what I needed and how to do it. The new flywheel even had the clocking marks on it.

SO,, I had a perfectly matched balanced new SPEC Flywheel. ZERO vibration issues!

Here is a crappy video I took at 11PM with just the flywheel installed and open headers to see if I was in the ball park vibration wise.
In real life, the noise was ear bleeding loud!

Yea Baby!!! The neighbors LOVED ME! NOT!!

Please click on the picture to play the VID. I wish I had a better camera...



Man it was LOUD and assume!!

Bill

NO VIBES!!!!!!!!

 

This thread just keeps getting better and better... great story Bill

 

So, I bought a 2004 Z06 and the clutch and brake fluid were pitch black. Ive flushed the brake fluid and used a syringe to replace fluid in the clutch master. My car still has issues shifting into 3rd when accelerating hard. Clutch pedal goes hard. im assuming this is because the clutch fluid is garbage in the rest of the system. Im going to have Able Chevrolet replace the clutch/fw/master/slave/tob and add a remote bleeder.

My question is. I dont know if the previous owner ever put a different clutch in the car to begine with. So, what if there is an aftermarket clutch in the car already and it doesnt have the "match balance" marks on the flywheel? Im not currently getting any driveline vibration so thats not a current problem.