I've been lurking for some time on here and really appreciate the tips I pick up by reading through this stuff. I've never posted anything and this may come across as nuts, but I had a similar issue with my 08 JKU Saharah. It took a little while to manifest itself did but it was right about the same mileage you are showing and, like you, I was still running stock wheels and tires and had installed a 2.5" BB. It started mild at first but then got very bad very fast. I double checked all my track bar bolts and so on... finally took it to the dealer and they replaced ball joints even though they were technically within tolerance. Still bad wobble on freeway bumps. They kept it for two days checking things and re-test driving. I finally get a call from service advisor, they found the problem, 'tires'. He can't explain why tires that appear perfectly good, albiet somewhat worn, would cause the problem. He says that they have a tech who just happened to have run into this before. They checked them for balance and rotated them several different ways still wobble. They borrowed new wheels and tires from an identical new vehicle and problem goes away with no other changes whatsoever. I went down and drove it and sure as heck problem solved. Much to the wifes chagrin this meant it was time for new tires and I'm really not the type to replace tires without upgrading and that meant new XD Addicts in 17x9 with 33's, to be upped to 35's when other upgrades can be afforded. No problems since.