X2 on the alignment. I had a problem simular to that and mine was the track bar not adjusted properly. When you have the alignment done have a thrust angle alignment done. Who ever does your alignment will say no because you can't make any adjustments to the rear axle but the point is to make sure your four wheels are tracking correctly. When mine was out of wack it felt like I was driving in strong winds all the time. But it was only evident at highway speeds. Another item is make sure your steering wheel is centered then do your alignment.
"It's just not enough, I need more, nothing seems to satisfy. I said, I don't want it, I just need it. To breathe, to feel, to know I'm alive"....Tool
06 Jeep Rubicon, 34k
95 Mercedes E320A, 80k
90 Mercedes 300D, 428k