For those recommending replacement of the pin box, I should have mentioned it in this post, but I replaced the pin box a few weeks back with a fifth airborne, 21k hitch. Interestingly, if you measure the thickness of the steel in the base plate it's exactly the same. With my calipers, and without removing paint they both come in at .23 to .24 inches of mild steel. Width of the base plate 12 inches. I replaced the pin box because I had another longer road trip coming up, and had concerns to where I felt it better to replace it that risk complete failure. At the same time, I bought a new hitch.
Regarding bed flex, no that issue isn't resolved with the Andersen Ultimate. If you watch the hitch base while backing up in soft sand/gravel, or other situations where it takes a fair amount of power to get things moving you get some bed deflection. I'm not sure if it's enough to cause problems though. The part where I was asking about the bed deflection/denting, indents in the bed or spray in bed liner were things I was looking into while trying to identify an occasional pop I would sometimes get out of the hitch. By the time of the above response, I had already been able to duplicate the pop while watching the hitch and it was cause by a 1/8 inch of so slip of the base on the truck bed that would happen with a pop, or jump if you will. Probably a result of the spray in bedliner being worn smooth, and having hardened where the hitch mounts. To secure the Utlimate base you install the hitch, put the weight of the trailer on it and tighten the top tube bolt down to 50ft lbs.
Finally, as to how the ball adapter works for those who don't have this hitch, you slide two mount bolts through the side of the adapter, then tighten 4 set screws to push the adapter away from pin box base plate until the two mount bolts are preventing further downward travel because of the lip at the bottom of the narrow portion of the kingpin (Using a torque wrench again). The 4 set screws surround the pin with the two set screws between the pin and the hitch ball forming a leverage point to where all of the pin weight is carried on the ends of these two set screws. The pin box of course was designed to carry the pin weight over a much wider areas, in this case the area of approximately that of a 10 inch disk.
As for the comments about the pin box being ****, I would have to agree it's minimal at best, designed to be as light and Cheap as possible. Couple that with a minimally designed and built hitch and things are likely to go wrong, which they unfortunately did in my case. Fortunately, I think the replacement components will work out better for me long term as the hitch in particular appears way over built if anything, and the suspension in the pin box should help soak up road shock and possibly help in extending the life of my equipment.
