On mine, I couldn't tell if the power steering was working or not with the wheels off the ground...... Sure could tell with weight on 'em though.

 

It’s like almost impossible to turn left to full lock if I turn it all the way right then try to turn in left it’s still incredibly hard

 

Even off the ground? If that's the case, then it's time for a new box.

 

Off the ground it’s perfect

 

I’ll send a video 1 minute

 

 

It’s not a video of the turning but it’s a video of all the steering components I know of maybe somethings off?
also does the gearbox look new to you the guy said he put a new one in

 

Ball joint?

 

Box does look new, fluid looks a little low. The problem is I went through 3 boxes through the parts store before one finally held up. I have the same problem as you with my 2500. Haven't looked into it.

If you want to check the ball joints just the tire up and grab at the 12 and 6 o'clock positions while pushing on one and pulling on the other, then reverse it. Also stick something long under the tire and push down. Any movement is bad. See what is moving.

If you plan on keeping the truck for a while and have the money buy a really good box, replace the power steering lines.

 

I’d like to try and do it as cheap as possible but as good as possible I want to keep the truck I’ll check the ball joints tomorrow is there a way maybe one ball joint went bad and it causing hard turning on one side?