Missing pilot bushing?
 

Thought I would cross-post this here to see if any of the heavyweights could chime in:

I had the 923 trans in my 912 rebuilt by a shop.
In the process, while they were in there, I had the flywheel lightened.
Ever since they put the drivetrain back together, the trans has been very noisy.
I have replaced the coupler bushings.
I have also replaced the shifter tower and guts several times, going from factory, and aftermarket short shifters, and finally to a stock configuration.
I even replaced the throttle rod bushings in the tunnel, thinking the rattling was the throttle rod hitting the tunnel walls. They were toast, but it only reduced some of the noise.

The shop thought it sounded like a ring and pinion problem, so they pulled it the last time I had a corner balance. They found zero metal shavings, bits, dust, or ugly wear patterns, and pronounced it healthy and buttoned it up.


Still a lot of gear whine.

Other than the noise, the car drives great. This weekend, I drove to non-stop to Watkins Glen and back, (5 hours each way) with zero problems.

My question, could all the noise be from not installing the pilot bushing in the flywheel before mating to the engine?

Thanks for your insight.

Bill K