How to make a wheel spin around 360 degrees seamless motion?

[COLOR=Blue]jan 7 2004
how to make a wheel spin 360 degrees in a seamless motion?

my purpose is to give realism to a car wheel which will spin in a seamless motion;
I´ve tried to to it with tweening but the wheel mc jerks at every rotation;
a couple of years ago I saw a very simple code which did exactly this , to make
a wheel spin around smoothly;
would you please suggest me how to do it ?
cheers[/COLOR]**