I have a 93 f-150, 4x4. Recently when turning either right or left, it will not come back to center, you have to turn it back manually, not too much force, but if you don't you'll keep tuning in that direction. Has power steering, auto. Wondering what it could be, ball joints, tie rods etc.?

 

How big are the tires you have on it, and what are they inflated to?

 

10.50's, 40-45#s
These tires ahve been on for over a year, problem just started. Thanks