One problem related to steering is loose has been reported for the 2006 Ford F-250. The most recently reported issues are listed below.
We were driving in a parking lot at a slow rate of speed when the steering let loose and we had no control of the truck. The truck crashed into a pole in the lot, and was unable to be moved due to loss of steering. It had to be towed away. Had this been a parking lot with cars and or people there would have been serious consequences. The impact from hitting the pole, caused my wife's neck to snap back and she has some strain in her neck. According to this link Ford has been having trouble with their steering and "death bump" action causing the trucks to shimmy out of control- we did not have any warning- just complete loss of steering> this needs to be addressed before someone is killed.