On and off for about a month I have been having steering trouble with my 06' F250 Super Duty Crew Cab 4 X 4 Short Box Diesel. It started when I was making a left hand turn at about 10 mph, I didn't turn the wheel all the way, and after completing the turn it was hard to return to center. I returned the wheel to center and everything was fine. A week later the same thing, then a couple days later the same thing. This went on for about two weeks, but only when turning left. After two weeks I made a left turn and had trouble getting it back to center, and then the wheel was locking just left of center and corrected it and then it went just right of center and it kept doing that. I pulled over and turned the wheel to lockout left and right a few times and then it was fine, for a few seconds and made a right turn and it did the same thing, the wheel was whipping back and forth (driving @ about 25 mph). I continued for about 100 yards parked it for about 30 minutes, checked all of the front suspensions parts (tie rod ends, ball joints, etc.), solid as a rock. I got back in it and drove down the road making lefts and rights and nothing, I thought it might be the steering dampener. I bought one, dealer only part, which I didn't change for a few days and nothing happened. I changed the steering dampener and for a couple days nothing and then it happend again, wheel oscilation/whipping back and forth. I pulled over and did the same thing in a parking lot, turn the wheel back and forth and turned in circles left and right and it was gone. I just put on new tires today and now the wheel isn't as responsive, a little delay when you turn it. When turning the wheel slightly to the left its like there is a high spot, like trying to turn the wheel up a curb from a stop. Can anyone please give me some advice? I checked for a Recall or TSB and nothing. I really don't want to have to take it to the dealership if I don't have to!