Saturday, when I went to back out of my driveway, I went straight back to the end of my driveway, stopped and turned the steering wheel all the way to the left to pull out and the truck suddenly would not move. The back tires actually started to turn and squeal while the front wheels did not move. I straightened the wheel out and the truck moved both forward and backward just fine. So I turned the wheel all the way to the right to head down the street and it did the same thing. But when I turn the wheel toward center again the truck moves. If you have the steering wheel centered and start moving at idle speed, as you turn the wheel either way you can feel it getting tighter and tighter until it locks up when the wheel is turned all the way either right or left. I had to go somewhere so all I could do was try to make wide turns to avoid turning the steering wheel fully to the left or the right. Yesterday, I jacked the front of the truck up and had my wife get in and start it. She then turned the wheel all the way left and then right while I tried rotating the wheels by hand. The passenger wheel would not turn at all. The driver wheel would turn a little but I had to exert some effort to get it to do so. When she centered the wheels, the wheels turned freely. Has anyone else had this happen and if so, what was the cause? My truck is a 2004 Dakota 4x4 with a V-8.