I have searched around, but no definite answers have came up. At speeds above 80 kph, there is a somewhat loud but very annoying whine that comes from the shifter itself, you can feel it if you rest your hand on it. Putting pressure up or right when in the 5th shift gate will make the noise go away. When I had the engine out earlier for other reasons, I replaced the clutch along with the pilot bearing and machined the flywheel - the noise didnt begin happening for roughly 4000km after that. Shifting into 5th itself is no issue, no grinding or drama. The shifter itself looks to be a B&M copy, the previous owner never said exactly. The bushing is in great shape and has zero play when I pulled it apart to see if it was something obvious. Its rather annoying to have that noise constantly ringing through the interior, has anyone encountered and fixed this? Diagnosing or testing may be a bit hard as the engine is apart at the moment.

 

I have heard of some short shifters being noisy in certain gears. That could be a possibility.

Dale

 

The shift lever could be ringing like a tuning fork, and if that is the case, then a little bit of damping could eliminate it. Is there room to attach some low-rebound rubber to the shift lever below the boot?

 

I too have what sounds like this exact same issue. Put it in fifth and the shift **** vibrates with any engine power applied. Push the **** up slightly and the vibration goes away. I recently had the trans refreshed and mentioned this to the shop. They said however that they didn't see any obvious problems.
Haven't used the trans yet, as it is still waiting for the engine to be finished.
Sorry I didn't exactly add any helpful info, but at least you know you're not alone!
Sub'd for updates.

 

Motor mounts (too hard/soft)?
Shifter bushes? https://www.rx7club.com/3rd-generati...build-1072268/

 

At the time this was going on (the last ~1000km) I had no shifter panel or boot, but I did had one of the dampening rubbers on the shifter, as well as a piece of silicone radiator hose on the bottom to take up the difference in diameter of a stock shifter vs mine. Also, there was a decently heavy shift **** on the shifter - removing it made no difference to the sound. Like I mentioned earlier, placing your hand on the shifter while it was making the noise allowed you to feel the high pitched vibration, kind of like when the dentist uses an ultrasonic scaling tool on your teeth.