Ever since I've had the car, it's vibrated like crazy starting at around 3000rpm and pretty much getting worse with RPM.

I marked the crank damper with white paint on both the inner and outer ring and sure enough, it slips (I guess they all do at some point). Does this seem like the likely candidate for the vibration?

If so, are any of the cheap aftermarket ones ok, like Dorman, Pioneer, Napa or even GM stock?

 

the flywheel and motor internals are stock? I dont think a harmonic balancer should cause a vibration that bad.

 

is it just RPM sensative or speed sensative to?

Try turning the drive shaft 180 deg.

 

The balancer is "0" balanced if it moved, it NO LONGER is "0" balanced,so change it before it shakes your engine to pieces.Or comes in two pieces and tears up the front of the engine.
If that isn't it take the drive shaft loose and turn it 180* at the rear end.

 

Thanks for the replies guys.

med_reject: I didn't think so either, but I can't figure what else it would be.

97formula1234: I do have a separate, speed-related driveshaft issue (starts around 80 or 85) which, when combined with high RPMs in 4th, is really quite horrendous. But what I was describing can be induced while parked, revving in neutral.

1racerdude: Yeah I recently read that the damper was zero balanced with a pellet weight, so since it has slipped, it's not any longer. Even so, I would be surprised (and happy) if the balancer would cause it to vibrate this badly.

Any comments on which of the above are ok to run? Cheapest?

 

Pioneer makes an SFI approved one that is not real expensive.

 

I just got back from Napa. I ordered theirs for like $70 or something.

 

When you rev it in nutral does it viberate? If no it means its not the driveline IE: driveshaft etc I would look towards the flywheel and balencer

 

Yes it does it in neutral. I hope it's the balancer. I pick it up today. If it doesn't change then it's probably the flywheel. And that would **** me off.