Leveling 5th Wheel

Question:

Hi, I currently have a 41 ft KZ venom 16k gvwr that came with a lippert 1621 pin box. I had that changed to a flex air 21k box 369535. I am also using a pullrite 20k ISR for RAM oem pucks. The new pin box cannot adjust enough to level the trailer, I am 4-5 inches nose high at this point. I’m assuming I need a different pin box but really like the way the flex air tows. It looks like the rota flex may lower the nose compared to the original 1621hd in the same mount position? Not excited about buying another new pin box but that seems like my best option. Any suggestions on the right pin box or other ideas would be greatly appreciated. Thanks!

asked by: Geoff W

Expert Reply:

I contacted Lippert for measurement comparison. The Trailair Flex Air 5th Wheel Pin Box, # LC369535, has a distance from bottom of king pin to top of box measuring 19.56" (king pin length approx. 4"). The Trailair Rota-Flex 5th Wheel Pin Box, Lippert 1621, # LC328329 drawing shows measurement of 13.54" from top of kingpin to top of box (king pin length approx. 4") 13.54 plus 4" being 17.54" will provide you an approximate drop of only 2". I don't think this gets you where you want to go. I assume you do have the pin box set in the best option of bolt holes and the head height on your 5th wheel hitch set to the lowest possible setting without contacting the bed rails.

There is also the option of raising the suspension on the RV with something such as the Dexter Trailer Springs Over-Under Conversion Kit, # K71-384-00.

expert reply by: Michael R