Search "death wobble". It could be the ends of your front track bar are worn out. Which causes something else to wear, which messes something else up.
The bolt on the front passenger side trackbar on mine was significally undersized (smooth part was smaller diameter than threads) and I think it's a problem on many TJ's. Credit here to Unlimited for one of his threads.
It had started to wallow out the factory trackbar hole, or the factory hole was never round in the first place. I never had a wobble (even over 100), but I can see how it would originate from here.
I replaced the bolt when I put in the new JKS bar and the interface was much tighter.