The knob itself is probably not the problem. The buzzing you describe is more likely to come from the "5" or "OD" switch--or the wires leading to it--which rests in the middle of the shift knob. You may be surprised how much racket that little switch can make.

The switch rests loosely between a recess in the top of the knob and the plastic, circular cover showing the shift pattern. You can gently pry out with a small screwdriver at the edge of the plastic cover and it will pop out of the recess without too much trouble. Don't pull the switch up very far or you may have to puzzle out how to reconnect the wires. Use some tape or a tiny piece of soft foam to build up under the tabs or wings on either side of the switch to hold it in place a little better. Don't use glue or anything difficult to adjust or remove. If you have a little more tension between the switch and the cover than when you started, you may find that noise is gone.

Good luck with it!

It should just pull off, don't bust yourself in the mouth when you do it though.

Mark