I have a very slight vibration that appears in the shift lever of my 90 535i 5 speed. Here's my observations:
1) only happens in 3rd and 4th gear
2) only happens during MODERATE acceleration / deceleration. Goes away when you go to either extreme.
3) stops immediately when you put in the clutch
4) does not vibrate the car at all, only the shift lever vibrates
5) appeared recently, maybe after I installed a new transmission rubber dustboot (?)
6) vibration speed changes as the road speed changes
Any thoughts? An archive search talks about transmission mounts, u-joints, center bearing...