Another dumb flywheel balance question...
Thread Starter
Pro
Joined: Mar 2005
Posts: 666
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From: Walton KY
Another dumb flywheel balance question...
I have a 94 LT1 6 speed. Over the summer I had a shop (now out of business) install a clutch for me. The idiot turned my DM and reinstalled it. In addition to engagement problems, I now have the dreaded out of balance vibrations that starts about 3200 RPMs and rattles the whole car. I have some dumb, yet simple questions.
If all he did was turn and reinstall, assuming it took a uniform amount off all the way around, it should not have been out of balance, right?
If so, does it vibrate because he did not put the FW back on in the same position it came off? How do I know how the wieghts line up with the crank?
When (not IF) I replace the DM, can I use the locations of the wieghts on the old DM in the same as the new DM?
How does one (or a shop) balance a FW if new? I know there was a thread for this somewhere and I cannot find it.
Thanks ahead of time, guys.
If all he did was turn and reinstall, assuming it took a uniform amount off all the way around, it should not have been out of balance, right?
If so, does it vibrate because he did not put the FW back on in the same position it came off? How do I know how the wieghts line up with the crank?
When (not IF) I replace the DM, can I use the locations of the wieghts on the old DM in the same as the new DM?
How does one (or a shop) balance a FW if new? I know there was a thread for this somewhere and I cannot find it.
Thanks ahead of time, guys.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
How the DM works, and why you have this problem:
Problem: By cutting the flywheel, the prior shop more then likely destroyed whatever was left of the rubber membrain. So the masses are no longer in balance.
Facts:
1) If you buy a new DM (which I recommend for street driven vettes), get an assortment of weights and match them to the fitments on the old flywheel.
2) The flywheel only goes on one way.
3) The new flywheel requires no further balancing.
I hope this clarifies the problem!
Problem: By cutting the flywheel, the prior shop more then likely destroyed whatever was left of the rubber membrain. So the masses are no longer in balance.
Facts:
1) If you buy a new DM (which I recommend for street driven vettes), get an assortment of weights and match them to the fitments on the old flywheel.
2) The flywheel only goes on one way.
3) The new flywheel requires no further balancing.
I hope this clarifies the problem!
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by bogus
1) If you buy a new DM (which I recommend for street driven vettes), get an assortment of weights and match them to the fitments on the old flywheel.
RACE ON!!!
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
You might not, but that's the GM spec. You see, the DMs are all pre-balanced to a set level, the weights are used to fine tune the balance to the engine.
It's kinda wacky, I know, but thems are da rules. I have NEVER heard of anyone having a balance problem doing it this way.
It's kinda wacky, I know, but thems are da rules. I have NEVER heard of anyone having a balance problem doing it this way.
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
you should get a set of weights that come in the box with the purchase of the new Luk OE dual mass flywheel. They are round, about 1/8" diameter and about 1/2 long. They press into the available holes at various points that are patterned on the inside diameter of the flywheel. Just put 'em in the same configuration as your original dual mass.
why do i know this? cuz i was all over it when the GAWD DAMNED FIDANZA WAS RIPPED OUT LOCK, STOCK & BARREL
why do i know this? cuz i was all over it when the GAWD DAMNED FIDANZA WAS RIPPED OUT LOCK, STOCK & BARREL
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
There is NO rubber membrane in DM flywheels. I know, I took one apart 
It's a thin metal flange to keep the coil spring in place.
Do you have this vibration when you are driving down the street, but push the clutch pedal in and keep the RPM's above 2K?
It's a thin metal flange to keep the coil spring in place. Do you have this vibration when you are driving down the street, but push the clutch pedal in and keep the RPM's above 2K?
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Thread Starter
Pro
Joined: Mar 2005
Posts: 666
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From: Walton KY
Originally Posted by 89 Paul in Cal
There is NO rubber membrane in DM flywheels. I know, I took one apart It's a thin metal flange to keep the coil spring in place.
Do you have this vibration when you are driving down the street, but push the clutch pedal in and keep the RPM's above 2K?
It's a thin metal flange to keep the coil spring in place. Do you have this vibration when you are driving down the street, but push the clutch pedal in and keep the RPM's above 2K?
I get it ANYTIME the motor is over 3200....revving in neutral, acceleration, clutch in or out. When the top is on it the vibrations rumble thru the whole chasis. Feels like the car is gonna come apart.
