Single mass flywheel = vibration in the shifter?

[Skant]

As a circumstance of having replaced the transmission (three times) and the flywheel and clutch (I describe the whole story in another thread titled something like $6500 and still whining on the freeway)...

I have a Centerforce single mass flywheel and a Center force dual friction clutch. Both new. Breakin was completed. These are mated to a transmission that came out of a 90-92 vette (older style ZF6)... so this stuff sits behind the LT4 in my 96 vette.

I have noticed vibration felt through the shifter. It's pretty smooth through most of the range, but particularly around maybe 4500-5500 the shifter feels like a vibrating massager. I don't seem to feel the vibrations in the seat of my pants very much... it's mostly in the stick.

This occurs regardless of gear. In fact, I can feel the vibrations (in the seat of my pants) with the clutch pushed in just reving the engine.

Is this normal for a single mass flywheel setup?

It seems sensible to me that the dual mass is there to dampen vibrations... therefore it would vibrate more without it.

Is this the case and it's just normal for this kind of setup? Or does it mean I have a new out of balance flywheel that had better be balanced before it wrecks something?

- Skant

[taegdh]

I wonder if when you changed the flywheel and clutch, if you should have also replaced the Harmonic Balancer.


As the reciprocating and rotating mass is balanced at the factory or when rebuilding, when you make a change on the back part of the engine, it might be beneficial to take a look at what's happening at the front part also.


Food for thought.

[Skant]

Well, I took it to a shop today that declared right away that it was not normal... it was pretty bad. And if it's left this way, it's likely to rattle loose or break something eventually.

They said the Centerforce flywheels/clutches are supposed to be prebalanced, but they're often out of balance. They're offering to try to balance it, but since it's an externally balanced system, they apparently can't balance the flywheel... only the 'cover'.. or something like that. So they can try, but if it's in the flywheel, they can't really do anything.

Is this all sensible? Or do I just need to talk to the right shop to be able to do the balancing?

They were saying that if they could get an LT1/LT4 crank shaft to run with the balancer, that would probably work. Obviously, getting the crank shaft out of my car would be cost prohibitive.

When will my luck change?

- Skant