Ray is right,
YOu do not have that functionality in 2000. 2001+ has physical dynamics but I would attempt to do a simulation like that with it... its very math intensive and would bog most processors and not show much at all for you. Better way would be to use Cosmos Motion, and use your assembly file, define a rotary motion on one gear, and create a coupler between the two that says for every degree of rotation on gear1, rotate gear2 by so many degrees (based on the gear ratio).
Wish I had better news for you...
Regards,
Jon
jgbena@yahoo.com