fifth wheel hitch

Take some time to consider how both the hitch and the trailer pin box system work together. I say this based on my experience with a Ram OEM hitch actually manufactured by Curt on my 2016 Ram 3500 and a Trailair pin box on my 2006 Mobile Suites 36TK3. The Trailair pin box has a pinned lower jaw that is free to rotate. A pneumatic spring and shock absorber control the vertical motion of the Trailair's lower jaw. This design is supposed to reduce rough road shock from being transmitted from the hitch to the trailer. However, as the jaw pivots like a scissor opening and closing, it also causes the hitch head to follow. The motion is a pitching back and forth of the hitch head. On my hitch the pivot point for the hitch head is six inches below the top surface. The Trailair jaw with hitch pin is 8.5 inches forward of the pivot point for the lower jaw and 2.5 inches above hitch surface. When hitched together the two pivot points are separated by a vertical distance of 8.5 inches and a horizontal distance of 8.5 inches. The pivot point for the pin box is mostly free to move vertically up and down. This can be observed from inside the truck as the shock compresses and extends on the Trailair pin box. When the Trailair is moving the truck experiences chucking back and forth. The pivot point for the hitch head does not move very much vertically,so the vertical motion of the Trailair causes horizontal motion of the hitch due to the rigid contact between the hitch head and the Trailair lower jaw pivoting together.

This motion would not be as pronounced on a hitch with a pivot point close to the hitch head. It also would be less with a pin box that did not pivot. I intend to keep the hitch and get a MORryde rubber pin box. Several members of my camping club have that combination with good towing results.

I will update after the changeover.