On my stock not lifted 99 xj 4.0l with 245,000, what would a wore out steering stabilizer be showing signs of? How do I know if it's bad? Could it be the reason why my wheels won't return to strait when they are turned completely one way or th other? Or the way my steering wheel rattles back and forth when I go over bumpy road surfaces?

 

Steering stabilizers don't do much except make your steering wheel feel a little smoother. Based on your symptoms, something else is needed. You tie rod ends could be worn, your steering box may be worn, your PS pump may be old and need to be replaced, etc etc the list goes on. Check all components

 

You may need new balljoints if the steering is not self centering after a turn.