Just got a 2009 jk, still has 36k warranty. FIrst time offroading I notice a bumping feeling (side to side) coming through the steering wheel. Almost as if everytime you hit a small bump it is being sent through the wheel. If you wiggle the steering back and forth quickly you can feel it quite a bit. I plan to take it in to be look at. Didn't know if there is a common problem, ie.. bushing, steering stabilizer, etc.. that I could tell the mechanic.

 

Do a search for steering clunk. Lots of threads on what you describe.