Last Friday I retrieved my 02 Z06 (2500 miles) from the dealer having had a new transmission, clutch, and flywheel installed. This was done because I had complained about loud neutral gear rattle. I was pleased that GM was willing to do this and the dealer did a great job of protecting my car while they had it.

As I'm driving home I noticed a subtle vibration at 2500 rpm as I am accelerating. It caught my attention as something that had not been there before. Over the last few days I've been driving the car and hoping that I can forget about it - trying to convince myself that it isn't really there. But it is.

Its right at 2500 rpm when accelerating. It does it in all all forward gears. Doesn't happen while decelerating. When reving the engine in neutral I don't notice any extra vibrations around 2500.

The vibratrion is pretty subtle, but it feels like the whole car is shaking. I feel the same thing at higher rpms - like at 4K and above.

I just scanned my shop manual and read about needing to install flywheel weights in the new flywheel like were in the removed flywheel and also about indexing the pressure plate properly on the flywheel. I wonder if this was not done properly during my repair.

I'd appreciate hearing from you folks if your car has a similar vibration or if it is always smooth. Also, if in neutral you slowly increase the rpms, are there particlular engine speeds where things are vibrating more?

thanks

 

My 2002 Z06 had vibration at 1600 and 3200 that shook the whole car (driving or in neutral). Problem was caused by the exhaust resonating. Fixed with an X-pipe. Could also be an issue with the way the exhaust is mounted/hung.

SportsCars

 

jeclarke, This is a complicated subject that, unfortunately, I learned a lot about. Drop me an email with your phone number and I'll provide the details.

Here is a quote from an old post of mine:

"The engine is externally balanced by weight pins in certain holes on the flywheel. Failure to preserve the balance will result in vibration that's quite difficult to cure. This means you must scribe the position of the flywheel on the crank to mark their correct relative alignment.

The new flywheel must go on in the same exact orientation as the old (the scribe mark ensures this) and new weight pins of the correct size must be installed in the new flywheel in the same holes as on the old flywheel.

Finally, torque everything to spec and use the "three-step process" where called for in the shop manual.

If you don't follow the shop manual precisely, it is very likely that you will wind up with bad vibrations afterwards. And please note that the manual is poorly organized. You must seek out ALL the references to the clutch and the flywheel, particularly critical are the "flywheel removal" pages.

My dealer screwed up an unnecessary clutch install on my car. The tech failed to scribe the flywheel-crank alignment and didn't transfer the new balance pins to the correct holes on the new flywheel. The resulting vibration from my then unbalanced engine would knock your fillings out. The cure involved three additional clutch installs and finally a two day visit by two Corvette field engineers who used specialized equipment to rebalance the engine. It's fine now but this sidelined my car for about 60 days and was a most unpleasant experience."

Ranger