There's a fairly easy straight-forward way to determine what is causing that kind of issue. Get a friend to turn the steering wheel back & forth while you watch the steering system from the front and look for things that are moving that should not be. Certain things like the tie rod and drag link ends will have a bit of rotational play but there should be absolutely zero side-to-side play anywhere.
This will show any loose bushings, wallowed out mounting bolt holes, etc. pretty quickly. The engine should be running so the guy at the steering wheel can turn the wheel long enough to let you see what's going on down there. Have him do short side-to-side turns much of the time which should allow you to spot the problem more quickly.