Kevin in Atlanta

1993 GTS. Twin plate clutch.

I replaced the stroked engine with another low mileage version - from the burnt GTS. Has ATI harmonic balancer up front.

I have a couple of problems I think.

Above 4500RPM in gear the shifter vibrates something awful. Out of gear the vibration abates.

Sitting out of gear - engine vibrates at around 1500RPM.

I think I need to balance the flywheel and clutch.

And then replace the TT.

Kevin

Kevin in Atlanta

I think I'll start with the easy stuff. Replace the transmission mounts.

This car was purpose built to do AX and there's no telling the abuse the mounts took.

After that I'll retest driving and if necessary move on to a rebuilt TT from Constantine I have in my storage unit.

Michael Benno

Hey Kevin

I also went through a little driveline vibration troubleshooting in my 5-spd conversion. Part of the vibration was from the rear transmission mounts so replacing them is probably a good idea. The other part of the vibration was mitigated by balancing the clutch. My new clutch discs didnt come with paint marks indicating the heavy sides so I had to determine that using a jig. When installing, make sure you have the heavy spots set up opposite each other. I'm not sure if the vibration would be caused by the torque tube bearings, but check with @Constantine he would know best with his experience.

Are you using the factory shifter assembly? Or are you using an aftermarket short shifter? If the vibration is limited to the shifter, it could just need some bushings or shims. I have the Hans shifter setup and I had some vibration in the shifter until I added some machine washers and a spring washer to take up lateral slack.

Hope this feedback is useful in your journey.

Mike

Kevin in Atlanta

Today I measured the distance from the front of the TT to the the bearing.

It measured 25". Clearly the bearing has migrated.