Bob,
I know you and others are correct, I also came to the same conclusion. I also am in discussion with Heartland. In fairness to HL and because of the cost in correcting my problem, I am giving them an opportunity to fix the problem in a manner that is best for all. At first glance it looks like a simple fix, undo 10 bolts and put the new one on, 1 hour tops. I wish..., in my desire to not type a diatribe here I am keeping it simple and omitting "the rest of the story" (al la Paul Harvey)... I really would like any forum reader that has a Trailair kingpin box to let me know what model number is on their unit, it may help in my discussions with HL. At this point I am opimistic it will be taken care of by HL.
Tom