The very first thing I would try is to go to an empty, level parking lot, aim at a point on the far end, and start the jeep rolling. Once you have stabilized the direction, let go the steering wheel and begin to accelerate slowly. Watch to see if the jeep shows any tendency to veer to one side. Then, if it remains stable, do the same thing, but brake gently and watch for a veer in direction. This will not tell you what is wrong exactly, but it should localize any problem to one side of jeep. There is also the potential that whatever you find is either indirectly related to, or not part of, the problem you are interested in. Get that addressed and see if it also fixed your first problem. After that look for play in the axle bearings and ball joints. You want to address potential problems starting with the wheels and working inward toward the steering gear. You might find a steering issue, and fixing it might mask a more serious issue where the wheels mount. Good luck.
