Redlinez

iTrader: (5)

Ever since my Spec clutch was installed we've had an engine vibration and have once removed flywheel,pressure plate, and clutch disc and had it supposedly rebalanced only to still have vibration. I'm being told that GM had a factory imbalance issue and not all flywheels were "neutral" balanced. I was told that the old flywheel had to have had a weight in it that needed to be transferred to new GM flywheel. Both are which are steel. My only argument to this statement is that no two flywheels are the same and how would the weight (if there was one) on one balance the next flywheel the same way. We also wondered if we clocked the flywheel wrong, but I believe it is keyed. I really need to resolve this even if I've already damaged the bottom end. Any help would be greatly appreciated.

Reboot

iTrader: (5)

When my clutch was replaced with a McLeod single disk, my mechanic had the new clutch and flywheel match balanced to match the setup that came off the car.

Scalpel

iTrader: (4)

This is exactly correct, especially on the C5s. Not only does the weight have to be transferred from the old flywheel to the new one it also MUST be transferred to the EXACT same position on the new flywheel. Once you do that, you MUST re-install the flywheel in the EXACT same orientation the original flywheel is installed. This is well versed in the GM service manuals, especially the Corvettes. The issue with the F-bodys isn't as big a deal b/c they aren't balanced like the C5s are. After a C5 is assembled they spin the motors up to a certain RPM range and measure the harmonics of the engine. They'll then add/remove weight to the flywheel to eliminate the harmonics = smoother engine operation.

The F-bodys don't get this treatment yet the procedure should still be followed to the "T". The only way to get rid of the vibration on the C5s was to get a GM engineer to come to the dealership with the harmonics tester and re-do the balancing procedure.

JMBLOWNWS6

iTrader: (17)

Mine does the same thing after they installed a new tranny.I dont know about you but it is really bad when cold.And around 55-65 mph. I am going to take it in a bitch about this because it was not doing this with the lemon tranny. Oh yea dI have a spec 3 carbon with spec flywheel.

Redlinez

iTrader: (5)

Thanks for the input. I guess it just didn't make since to me to transfer weight from one to the other since the flywheels wouldn't be the same you would think. I guess if they are factory neutral balanced then the weight is put on after it's a rotating assembly to counter any imbalance in the engine it does make sense.

Redlinez

iTrader: (5)

I wonder if my ASP pulley would throw it all off anyway. Can it be done in the car? I mean, if the engine has to come out, there wouldn't be a stock crank left in anyway I'm sure it can be done, but I gotta wonder how much they would charge me.

Scalpel

iTrader: (4)

They don't have to pull the motor to do the balancing procedure. They do it with the motor in the car. The ASP pulley hasn't been shown to cause any vibrations, etc with the C5s that I know of. I had one on my C5 and when I did my Ram Clutch (402/6130) I followed the procedure above and never had any issues.

Phil99vette

iTrader: (11)

I had an engine guy look(check balance) at the factory internals when I built my forged SB. The factory engine appears like it is 0 balanced, so the flywheel should be 0 balanced also.
Phillip