I have a 2012 F250 4x4 6.7L Diesel with around 114k miles on it. Jut in the past couple weeks it has produced the following issue:
At start-up/during warm-up it when I make a turn (left or right) and hit at least 40mph the steering feels heavy and pulling to the right, all of a sudden it seems to release and dart a little to the left. It does this for about 10 miles then it is fine. Steering is a little loose, 114k miles and previous owner had a plow on it but once it straightens out it is fine for the rest of the 45 mile treck. Tires are new Goodrich All Terrains, no visible signs of a belt being broke. Anyone else had this issue? Any suggestions?

 

Check the fluid in your power steering and also check your steering stabilizer to see if somehow it has a slight bend in the shaft. First impression tells me it is going to be your power steering pump going out, but always check fluid first.

Also, might want to jack up the front end and see if you have play in the ball joints.

 

Possible brakes dragging? On my 7.3 stuck caliper slide pin resulted in pull during braking that I didn't notice till I was naturally doing counter steer and wife pointed it out. Could they be sticking until it heats up?