I'm having trouble getting the steering wheel to slide onto the shaft far enough so that I can start threading the nut onto the end of the shaft. Part of the problem is that you have to do it at the same time that you're installing the cup that supports the horn button. It seems like the bearing assembly is not far enough down the column tube or the sleeve that fits into the bearing isn't inserted far enough.
Right now the bearing assembly is flush with the top of the column. Should it be further in or should the sleeve be pressed down more into the bearing?

 

Maybe your truck (an F-1?) is different than my '53 f-100. But, I had sort of the same problem. I had to loosen up the clamp that tightens the column to the steering box and slide the column down a bit more onto the box to get the shaft to extend up far enough to mount the wheel.

 

I never would have thought of that. Thanks for the tip, I'll give it a try.

 

Turns out my column is already all the way down onto the steering box so I'm not able to move it and expose more of the shaft like JVMCC suggested. The only other solution is to move bearing assembly deeper into the column. I removed the column from the truck and moved the bearing assembly so that it's about 1/4" below the top of the column. That solved the problem.