Will a Reese Sidewinder Replacement King Pin Offer More Clearance than a Fabex 663 Pin Box

Question:

I currently have a 28foot foot Cardinal fifth wheel with a FABEX 663 pin box. I need a longer pin for a short bed truck. Will a FABEX 665 pin or one of the aftermarket replacement pins for the FABEX 665 fit? Thanks

asked by: Todd W

Helpful Expert Reply:

You could use the Reese sidewinder fifth-wheel king pin # RP34FR on your Fabex 663 pin box, but the # ST400-5AS16K sidewinder you referenced will only fit Leland brand pin boxes. The # RP61420 fits both the Fabex 663 and the Fabex 665 pin boxes.

To determine whether replacing your pin box with a Sidewinder will give you more clearance, you will need to take some measurements. Use the formula below to ensure that there will be enough space between your truck cab and trailer when you are executing a 90-degree turn with the sidewinder installed.

(A + B) - C = Clearance
A = Distance from center of 5th-wheel hitch jaw to truck cab in inches
B = Length of Sidewinder arm in inches (22")
C = Width of trailer in inches divided by 2

I am including some links to additional information on sidewinder king pins for you to reference.

expert reply by: Sarah L