Sounds like either the p/s pump is going out or the joints in the steering shaft have seized. My Durango pump went out all at once. No assist whatsoever and I could barely turn the steering wheel. I had read about the steering shaft joints getting stiff or seizing but mine had already been replaced.
Ball joints would prematurely wear out and come apart. I happened to be standing in the driveway one day when my son stopped by in his Dakota. I heard the clunk and saw the tire jerk as he turned in. Needless to say, he went home with new ball joints.


Tim