My 1993 Ford Explorer axle problem.

Get a second person to move the tire back and forth watch to see where the movement is once you identify the part go to the local parts store that have pictures of the front axle and show them where it's loose. and you will need to replace the part and get an alignment. It could be any of the following connecting rod, tie rod end, stabilizer arm or drag ling joint bad. if it was up and down then it would be king pins or wheel bearing loose.