Yes, the way to check for ball joint or steering linkage slop is with wheel jacked off the ground

To pinpoint the slop, lie on the ground watching the steering linkage. Reach up through the open door and turn the steering wheel to and fro
* If the steering linkage moves up and down even a little bit, that's bad slop. If it is the idler arm moving up/down, new bushings are about $10 and can be replaced with hand tools
* if the tyre moves up/down but the steering linkage does not then it's either bad ball joints or loose wheel bearings. Try adjusting the bearings. If the wheel doesn't spin smoothly pop of the grease cap and see if the bearings are dry