I would still check the CVJ... maybe he has an old model Sonicare or a generic unit

Yes. Changing the oil and checking for metal debris might help determine if the problem is inside the tranny.

Your toughts?

 

perhaps it's something much simpler...is your shift **** an aftermarket piece?

mine used to make the exact same noise you are describing because the tiny little screws used to hold the **** in place had loosened.

 

My thoughts are that there is a vibration , it could be a normal or abnormal vibration and its getting telegraphed up the shifter linkage parts , causing the shifter to buzz .
I think I would put the car in neutral and run the motor to see if I could get the shifter to buzz . If it will buzz when in neutral ...

 

The shifter is stock. No noise when I out the car in Neutral. I did replace some of the cv joints, I don't remember which one's (I'll need to check the work order) about a year ago.
Thanks all for the suggestions.

 

I had this on my second 993 -- it was the engine mounts