Some wander comes from worn steering shaft, worn tie rod ends, worn ball joints, and worn-out track bar. The remainder is split almost evenly between (1) worn-out sector shaft bearings in the steering gear and (2) worn out suspension bushings. On a 4WD, you probably cannot manually test the bushings. But you can be assured that if you have over 100k miles on them, they're well worn; over 200k miles, they're worn out.
Years ago, I installed an SSI stabilizer on the steering gear on my '98. (The stabilizer removes all the stress from the little bearing on the sector shaft.) That removed a lot of wander. More years passed and the wander returned. I finally had the 8 front suspension bushings replaced in 2011 or so. That pretty much eliminated the wander. Replacing the track bar and the steering shaft at the same time eliminated the slop in the steering.