Ford F-150 4x4 with power steering (gear box-not rack and pinion) Hard turn in either direction binds and jerks stirring until it gets back in place. There is also a lot of play in wheel. Changed ball joints upper and lower - both sides, tie rod ends good, power steering pump checked, surpentine belt good and greased what needed to be greased. What next? Very puzzled.
On the steering box there is a screw with a locking nut around it. With engine off check for play at the box. If neccessary loosen up the nut just a little so the screw can be moved. Notice where the screw and nut are before proceeding. Turn the screw clockwise a little at a time. Check the play in the steering wheel each time so you don't over tighten. Once play is removed hold screw with screwdriver when tightening nut. If you don't the screw will tighten with the nut making the steering too tight.