Air Ride 5th Wheel Trailer Replacement Pin Box for a Lippert 1621HD Pin Box

Question:

Re: 35-946229 UltraFab Trail Air Kingpin Box - TriGlide - L05 Questions: 1 Is this pin box compatible with Lippert 1621HD? 2 Could the distance between first hole center to king pin be shortened by 1 1/2inch to 16 1/4? This will permit to accomodate a truck bed box equiped with a Pace Edwards Roll Up Cover without touching the sides when fully turned side to side distance between rails is 59 3 Is it CSA approved? 4 Detailed dimension sheet available? Thanks for replying

asked by: Florent V

Expert Reply:

Ultra-Fab does not make an air ride coupler for a Lippert 1621HD model pin box, just the 1621. However, 5th Airborne does have a unit that will fit. It is the 5th Airborne Premium Fifth Wheel Air Ride Coupler, # RP78FR.

You cannot modify the pin box because doing so will not only void the warranty but it will also compromise the structural integrity of the unit, make the capacity, unknown, and it would not be safe for use.

The 5th Airborne unit is CSA approved. There is an instructions sheet available which I have linked for you and I will be happy to provide the key measurements for you.

On center, the side to side distance between bolt holes is 7-7/8 inches.
On center, the distance between holes up and down is 2 inches.
The bolt holes have a 5/8 inch diameter.
From the center of the front row of bolt holes to the king pin center is 17-3/4 inches.
From the center of the back row of bolt holes to the king pin center is 25-5/8 inches.
The pin box width is 12 inches.