I have a '11 Limited and the right grip has a split in the rubber. Can just the rubber be replaced?

 

Unless there's some kind of warranty, I don't know if it can be replaced without buying a set of grips. But have you considered super glue? I think it'd be an easy fix. Just a thought.

 

Without seeing the tear/rip, I'm not sure. But unlike after market heated grips that mostly use a strip under the grip and allow most any grip to be used... in HD heated grips the element is a part of the grip itself.