After making my turn onto the short road into the parking lot at work, there was a loud 'clunk'. I felt it in the floor, too. The truck was steering funny. I went out and looked at it, and the upper ball joint on the driver's side has come 'unscrewed' out of the control arm. Yes, it's all oily from the steering box leaking. But why would it come out? The ball joint itself was not bad. (it's definately bad now, the boot is ruined)