It most likely needs grease. If it hasnt been greased in awhile, you may have to remove the zerks, insert them into your grease gun and pump grease through them to get the 'hard' old grease out. Then take a small pick or toothpick and dig in the hole on the axle and remove as much hard grease as you can. Then, reinstall the zerks. Jack the front of the tractor up so the front wheels are off the ground. Spray WD40 around the spindles as you rotate the steering to loosen them up. Then, pump new grease into the axle while rotating the steering to work the grease around the spindles. The grease will come out the top and bottom of the spindles. This is ok! Just wipe it off. You want to flush that old gunk out of there. Then, make sure your front tires are 12-14psi. That should do it! Been using this procedure over 20 years. Works everytime! Just remember to regularly grease your axle from here and you'll be fine. Good luck! Disclaimer: If your center axle pivot is worn and sloppy, just get a good used axle and replace it.