All over the road...?

Hi everyone. I'm Misty. I'm new here and a new jeep owner. I recently purchased a 1999 Jeep Wrangler TJ. The frame had been reinforced in a couple areas and the rest looked good. The tires on it were 35's that were really worn (pretty evenly) when I bought it, so I bought a new set of 33's. I took it to my mechanic for a once over and he told me that all the front end parts are brand new, but it is desperately in need of a wheel alignment, but he does not have the equipment to do that. He suggested a local shop and they got it right in. Did the wheel alignment and realized that the rear "traction bar" (I think that's what he called it) was never replaced when the lift was installed, so it was too short and needed to be replaced because it will cause driveability issues. I said go ahead and do that, too please. Well, he called me today. Everything done, redid the wheel alignment, took it for a test drive expecting it to be much better. Instead, it's all over the road. What could be the problem?