Reply To: How would I rig an engine motor belt to go round and round (and round and round)?

You don’t necessarily need to animate the belt, only loop the texture to give the illusion of the belt rotating.

You could use a noise modifier in the graph editor if you want to add some wobble, you only need add a duplicate keyframe at the start and end of the timeline to add the modifier. You may want to consider wobble on the engine itself.