I have a 2004 Nissan Frontier Crew Cab 4 wheel drive with the standard V6 engine. When cold it is very hard to turn the steering wheel to the right. If front end of truck is jacked up the power steering seems fine. Lower the truck back to the ground and the wheel becomes very hard to turn to the right. All of the steering components appear to be in good shape & nothing is hitting the frame or other parts under the truck. Power steering resevior is full & the fluid does not appear dirty. Power steering pump belt also appears to be in good shape. Truck turns to the left just fine, only turning right does the wheel become very stiff.
Try changing the PS fluid.
Not too expensive and it might help.
Otherwise, it might be a problem in the control box on the steering rack.
No steering rack - this has the ‘old’ style steering components, Steering box, idler arm, centerlink, & tie rods. If it was the power steering fluid, shouldn’t it be stiff turning in box directions?
“shouldn’t it be stiff turning in box directions?”
Not necessarily if it’s a sticking control valve etc.