I have a little shimmy/wandering and a general slightly loose feeling in the front end of my Unlimited Rubi. Not bad, but have hit some bumps and gotten a little wobble and the front end just seems a little looser than it should. I have checked the basics, track bar and drag link and tie rod ends and bushings. The only thing that seems to have any play are the ball joints. I have read that it's normal to have some up and down play in the upper ball joint but not the lower. I do not have any lateral play with the front off the ground.
My biggest question is how can the top have vertical play and not the bottom? They are pressed into a solid piece so how can one move without the other?
I am getting new tires and wheels this week and have a 2000 mile trip planned in 2 weeks. I plan on getting an alignment done but would like to address any issues prior to that so as to not have to get a second alignment.
Yes, it's possible for 1 ball joint to go bad. However, ball joints are covered under warranty. I had my dealer replace mine before I hit 36k miles. Only one balljoint was bad and they replaced all four. I had a 2.5" coil lift and 35s at the time, but they still honored the warranty.
If you are out of warranty, I recommend getting re-buildable after-market ones like Dynatrac's Prosteer. They're pricey, but worth it. I would try to do it before your 2,000 mile trip. If the ball joints are very loose, you may damage your wheel bearings and can be dangerous driving long distances.
2018 JL Rubicon Unlimited, 6-speed, White
1985 CJ-7, 4-speed, 258 I-6, 3" Springs, 33" BFG AT, Gunmental Gray