This has been an interesting read. I tow 19,000 lbs with the Ultimate with zero problems. But I do have a rubber bed mat and a mor-ryde pin box. There seems to be some focus regarding a marginal pin box that has nothing to do with Andersen. I underestimated some RR tracks on an AZ highway last week and really bounced around my 5ver. Other than some broken stuff inside, furniture shifted, broken shelf with the DTV receiver, an MCD shade half off its brackets and a very angry DW, no other damage. Took a close look at the Andersen and all OK. So I can't help but believe that the OP's problems are not related to the Andersen.