With the steering wheel locked and front end raised up off the ground, there should not be hardly ANY free play in the wheels when they are moved up and down or side to side. Most likely cause if you get free play in all directions in one wheel is the bearings. If it were only side to side I would say look at the tie rod ends, but it sounds to me more like bearings. 1.5 inches sounds like an excessive amount of play, and is definitely enough to create that wobble you describe.
