Flywheel balance weights
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Joined: Jun 2000
Posts: 66
Likes: 3
From: Camp Hill PA
Flywheel balance weights
I had the clutch and flywheel in my 02 Z06 replaced under warranty a couple of months ago. The installation took a day longer than expected because the dealer was getting conflicting information from GM technical support about whether or not to move the flywheel weights from the old to the new flywheel. He was finally told to move them.
I have read reports on the forum about the necessity of making sure the flywheel is indexed properly to the crankshaft and that the balance weights were moved to the new flywheel. I also have a GM Service Manual and that tells you to move the weights.
I get the car back and notice a vibrations at 2500 rpm and also between 3500-4500 rpm in any gear when the engine is under load. It wasn't horrible but very annoying.
After a few weeks I took the car back to the dealer and he checks it out and ends up scheduling a GM field engineer to look at it. The next week the engineer shows up with instrumentation and balances the engine in the car.
All that was done to fix the situation was to remove the balance weights from the flywheel - so there are now no weights. Didn't need to remove the trans and driveshaft to do this. I didn't speak directly to the engineer but the service manager told me that he was given bad instructions from GM during the clutch install and that they should not have moved the weights to the new flywheel and that the service manual is wrong.
My car is great now.
So I'm really confused as to why what was done to my car is the opposite of what some of you have experienced and what the service manual says.
I'm wondering if GM actually changed their design and balancing process because it was so confusing to the dealers.
Does anybody have more information?
I have read reports on the forum about the necessity of making sure the flywheel is indexed properly to the crankshaft and that the balance weights were moved to the new flywheel. I also have a GM Service Manual and that tells you to move the weights.
I get the car back and notice a vibrations at 2500 rpm and also between 3500-4500 rpm in any gear when the engine is under load. It wasn't horrible but very annoying.
After a few weeks I took the car back to the dealer and he checks it out and ends up scheduling a GM field engineer to look at it. The next week the engineer shows up with instrumentation and balances the engine in the car.
All that was done to fix the situation was to remove the balance weights from the flywheel - so there are now no weights. Didn't need to remove the trans and driveshaft to do this. I didn't speak directly to the engineer but the service manager told me that he was given bad instructions from GM during the clutch install and that they should not have moved the weights to the new flywheel and that the service manual is wrong.
My car is great now.
So I'm really confused as to why what was done to my car is the opposite of what some of you have experienced and what the service manual says.
I'm wondering if GM actually changed their design and balancing process because it was so confusing to the dealers.
Does anybody have more information?
Drifting
Joined: Jul 2002
Posts: 1,320
Likes: 0
From: Duncanville Texas
Re: Flywheel balance weights (jeclarke)
I did not think there were actual weights! Normally they drill holes to remove weight and that balances it....
Someone chime in and let me know if I am wrong.
Someone chime in and let me know if I am wrong.
Safety Car
Joined: Jan 2000
Posts: 4,965
Likes: 0
From: Midlothian, VA
Re: Flywheel balance weights (jeclarke)
I didn't speak directly to the engineer but the service manager told me that he was given bad instructions from GM during the clutch install and that they should not have moved the weights to the new flywheel and that the service manual is wrong.
Melting Slicks
Joined: Aug 2000
Posts: 2,248
Likes: 1
From: Newland US
Re: Flywheel balance weights (jeclarke)
Sounds like a case of CYA with respect to the service manager. :nono:
Maybe if the flywheel wasn't properly indexed to the crank, THEN removing the weights might have brought it within tolerances. But that scenario is pretty far fetched in my mind. A case of two wrongs making a right through coincidence.
Glad ya got her fixed.
Mark
Maybe if the flywheel wasn't properly indexed to the crank, THEN removing the weights might have brought it within tolerances. But that scenario is pretty far fetched in my mind. A case of two wrongs making a right through coincidence.
Glad ya got her fixed.
Mark
