Steering Box or Steering Shaft?
 

I've been battling a steering issue for a while and it's been getting progressively worse as time goes on. Over time, I've replaced most everything up front to address other issues. Wheel bearings, ball joints, tie rods, idler arm, pitman arm, etc. Multiple alignments with print outs that were what they should be. New tires, equal tire pressure, etc.

The best way I can describe it is an unequal resistance from left to right. There is no binding, but the resistance is not equal. It is most noticeable on highways or straight roads to the point that it feels unsafe. It likes to "dive" to the right with little steering input. But, if you turn the wheel to the left at the same force, it behaves normally. It's only directional and only affects the right. It's not a road crown issue. I have used the adjustment on the steering box to tighten things up, and it does. But, it also makes this particular issue even more extreme/noticeable.

I'm at the point of thinking it has to be either in the lower steering shaft u joint close to the gear box or is weird gear box wear. There's a lot of clunk in the lower shaft when the steering wheel is slightly moved back and forth, but I don't know if that is directly related. If I reach down under the hood and try turning the shaft with my hand (with vehicle on the ground), I get a lot of resistance/hard to move to the left, but very easy to move to the right...the exact issue I'm having out on the road.

Opinions?

could be a bad box. I wouldn’t expect the shaft. Also it doesn’t hurt to double check the work you or someone else has done. Drop the front skid plate and verify everything is tight. It almost felt like this when my pitman arm was loose on the output splines of the box. Have someone inside the truck shake the wheel back and fourth and see if you see any looseness or splines moving inside the pitman arm.

this can even happen if a new pitman arm is installed and not torqued properly.