Has any one experienced steering problems or steering box problems on F- series 250's?

What symptoms did you have when the steering box went bad? I have a 99 F-250 that has a bad vibration at very slow speeds when making sharp turns in either direction. I havn't yet taken it to get it checked out yet.

I have a '93 F-250, 4wd, extended cab with the 7.3 liter diesel and 5 speed gearbox. After making sharp turns, the steering would go into a very severe "shimmey". The steering wheel felt like a tie rod end had broken. After some basic troubleshooting, nothing obvious turned up. Upon checking the power steering resivour I discovered that I had mistakenly over filled it. I removed the excess fluid to the hot level and the problem went away.