Sidewinder 5th Wheel Pin Boxes to Provide Turning Clearance

Question:

I have a solitude 310 with the trailair rota flex #1621. I am using an anderson 3220 hitch mounted in a 2017 gmc denali standard box 3500. This combination is damaging my inside rails of my pickup. I have read that this kingpin should not be used with the anderson hitch, this after the salesman sold me on the anderson. Can you help me with this?

asked by: Kevin M

Expert Reply:

Some 5th wheel adapters including the Andersen Ultimate # AM3200 and the similar Ultimate 2 aluminum version 3220 can only be used with fixed pin boxes. The reason you have seen damage to your truck's bed rails is that your setup allows two pivot points, one at the gooseneck ball on the Andersen adapter and one at the point where the king pin enters the adapter's coupler box.

Usually the best solution for a short bed is a standard fixed 5th wheel hitch like Reese M5 5th Wheel Trailer Hitch - Single Jaw - 20,000 lbs # RP30928 and a replacement 5th wheel pin box called a Sidewinder which provides one pivot point at the rear turret of the pin box only. This means the pin box itself remains wedged in a straight line behind the hitch (where it will not hit your bed rails) but allows the trailer to pivot at that rear turret. An example of a Sidewinder pivoting pin box is part # RP61422. This and all Sidewinders shift the pivot point to the rear by a full 22-inches.

You can refer to the linked articles for more on Sidewinders and 5th wheel adapters. Please feel free to tell me your cab style and bed length and I will be glad to recommend a hitch for your 310GK trailer.

expert reply by: Adam R