05CTSV

iTrader: (16)

Who has a vibration at 2200 rpm in their 04-05 LS6? If so, what mounts, clutch, etc to do you have? What have you done to fix it?

NIKDSC5

iTrader: (10)

I have zero. Stock suspension (still ) 8.8 w/cf drive shaft. CS trans mount, UMI MM monster clutch with 18lbs flywheel.

05CTSV

iTrader: (16)

Awesome, about the same setup as me. My vibrations got worse when I put in the UMI, so it's good to know yours has zero. I'm just trying to rule obvious things out before I pull the transmission and look for trouble. My monster clutch has about 20k miles on it, I have the 28lb flywheel.

serik21

I had none with last setup. Havnt ran the car with the current setup

Last setup
Stock balancer
Ls9r clutch with light aluminum flywheel
8.8 diff two pieces dss drive shaft
I had a slight vibe around 45 mph but it was speed specific not rpm specific
And was due to how my diff was setup.
Cs mounts all around.

BudRacing

iTrader: (3)

When exactly is the vibration happening?

While Driving and/or standing still?
Clutch in/out?
Only at 2200? or 2200 and above?

05CTSV

iTrader: (16)

I also have a Fluidampr 740121, just installed. That was one of the first things I replaced when the vibrations started.

BudRacing

iTrader: (3)

My only guess would be flywheel balance.

Was the vibration there before the fluidampr and did that help at all if so?

05CTSV

iTrader: (16)

I also noticed that when it vibrates if I lightly push on the clutch, I can feel the pulses in the clutch pedal. Still seems to engage/disengage and shift OK. I have noticed some difficulty downshifting from 6th to 5th. I have to wait what seems like 2-3 seconds before it will move from 6th o 5th. Up shifting is fine in all gears.

DMM

Every LS6 will have this vibration at 2200 RPM if the balancer is bad or has been removed and not reinstalled clocked in the same position.

All the LS6's were spun up on a balance machine and the balancer was drilled before being crated for shipment. Once you **** with the balancer, that OE balance from the factory is gone.

05CTSV

iTrader: (16)

How would you clock an aftermarket balancer? How would you ever replace a balancer? I thought the LS motor was internally balanced and the pulley is really just a damper, nothing to do with balance and would cause vibration if it's bad since it would wobble. Are there any pictures noting the orientation if you had to replace a bad balancer?

76Y82

Moderate (definitely noticeable)

-Stock clutch
-Stock balancer
-Revshift 80A motors mounts

2004 LS6 with 44k miles. Haven't done anything to fix it yet.

DMM

"As for LS6 engines, which boast a higher redline and some different reciprocating components than the LS1, they're sent to a separate station for a more specialized balance check. There, each LS6 is fired on natural gas and run for about two minutes on a transducer. If an imbalance is detected, weight is modified at either the harmonic balancer or flywheel. It's an additional step that ensures the LS6 is one of the smoothest engines in the world."

Read more: http://www.superchevy.com/features/vemp-0205-chevy-corvette-ls1-ls6/engine-redline.html#ixzz3Y4dPIlY7
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And that's what I'm saying...once you remove the LS6 balancer you're fucked bc there is no way to get it orientated the way it was from the factory without a keyway, or being very careful and marking, which nobody does.

rand49er

None whatsoever.

Current setup: Pinned front pulley, Katech LS9 twin-disk clutch kit.

Former setups: Never had any vibration when OEM nor when I had UUC lightweight FW with stock clutch.

05CTSV

iTrader: (16)

Very interesting. So really it's a roll of the dice, some get luck and end up with no vibration and others, like me, get hosed. Special LS6
Edit: Now I have proof to show my wife that the motor is fucked, need to replace it, hmmm LSX454!

DMM

Don't worry... She'll only make you regret it until you file for divorce.

ls1247

iTrader: (2)

So basically your ls6 could be externally balanced if it needed this additional step at the factory.

Mine had it before and after the ati damper install and balanced clutch assembly install.

It isn't bad but if you look for it, it's there.

05CTSV

iTrader: (16)

Definitely don't have to look for it with mine. It's very noticeable.

Becker

iTrader: (4)

thats good to know DMM on the balancing...

05CTSV

iTrader: (16)

I might go back to the blue revshift mounts, even when the bolt came loose on the old set they still had less vibes than what I have now with the umi mounts. Revshift sent me a new set under warranty, but I had already put the umi mounts in.

jttopper1

Mine was flywheel ,at 2100 ...always no matter gear or speed . replaced with ls7 clutch kit , no more vibration