I have a spare upper shaft -
I am not the a pro on this, but have worked with them- here is what I’m thinking- and there is a reason behind the method here-you disconnect so you do not over rotate the steering wheel and ruin the clock spring, and also this takes the bearings out of play in the shaft under the airbag.
I would set the wheels straight and anchor the steering wheel with the seatbelt and disconnect the shaft under the dash and at the steering gearbox and rotate it both ways- if it acts odd you need to first check the bearing (it runs in in the white collar nearly straight down from the brake fluid reservoir)
If it moves freely you can turn the steering wheel inside BUT NO MORE than when in use.
Now, all that aside, you can have drama going on in the gearbox or a linkage bind - when you have it disconnected you should be able to put it on jack stands up front, start it up and turn the wheels both ways by hand
You can also disconnect the drag link at the pitman at any point and just move the front linkage by the wheels -
So its-
- linkage bind
- gearbox drama
- shaft bearing/shaft u joints
- steering assembly above the shaft in the cab (unlikely unless it has been wrecked or someone got violent removing the steering wheel)
I would soak the bearing under the hood with WD40 or any good penetrant /lubricant first just to see if that improves it- if it does you need to start there- the bearing alone is said to be hard to find but one member was working on it through Kaman, a specialty bearing dealer - it likely can be found and we need to know if you do. Salt spray and manifold heat are the enemies of this bearing, and If I ever go back into one I’m adding a zerk or a spray grease port.
Good luck, keep us posted - when you learn and share , we learn.