I have a similar issue to OP on mine where the screws go in half way even after clearing things out with a smaller drill bit. The screws still need to travel about half an inch before they secure the bar. Did you ever resolve this issue?
Update on my "wandering" feeling. I knew it wasn't there when I got it! I had taken the JT in to the dealer to install a tonneau cover and they had filled up the tires to 44 PSI. I brought them back down to the 38 recommended in the car door and there is a significant improvement. Problem...
My stock Overland with 3.73 does this "wandering" thing a little bit. I have the rear Trac-Lok differential option. My general feeling is the issue is with my reaction to feeling a bump and how I would react driving any other vehicle. I notice it most when I glance away for a moment and I'm...