the gear box adjustment is adjusted in all the way

 

Then I'd say it's no good. Have some one in the truck move the steering wheel left to right, (gently and without the truck running)while you look at the pitman arm. If the wheel is moving alot and the pitman isn't, then the prob is gear box and/or from there back to the column, like the intermediate shaft slip joint or the small u-joints.

 

I tightened my steering box up also and it got rid of all the slop but I wander all over the road because when u adjust it in so tight it makes the steering wheel hard to turn. I am just gonna buy a brand new steering box...... get her to drive like a cadilac

 

where is the best place to buy a new gear box and how much do they usually cost

 

I have replaced everything under this pig except the steering shaft. Still drives like a boat. What gives?

 

Do you have the T steering, or the inverted Y? Have you replaced the steering box? If so, what brand?

 

Not sure about the T or Y. Steering box from Auto zone.

 

That's likely the problem..... a fair few of the 'rebuilt' boxes are worse than what you are replacing. Grab a friend, and check the steering, see what moves, that shouldn't, and what doesn't move, that should.

 

Like mentioned, the reman boxes from autozone etc can be just as bad (if not worse) than the box you are pulling. A good way to check the box is to have someone slowly steer the wheel back and forth a few inches each direction (engine off), while you check the movement of the steering shaft going INTO the box. Notice if the slight moment of the input shaft is equal to the movement of the pitman arm. My guess that this is where your problem lies. Especially if you have replaced everything down stream of the pitman arm.
Here in AZ we have a good shop called Benchworks that rebuilds the boxes to better then new.
Another route for a box could be Redhead. Though, they seem to be hit or miss too.

 

I'm extremely satisfied with my Blue Top steering box. Much cheaper than Red Head, and a very good result. I tried three different Autozone steering boxes (all were terrible) before dropping another hundred on the Blue Top. That box has been on the truck for over 9,000 miles.