How to Measure Installation Height for a 5th Wheel Hitch on a Custom Made Bed

Question:

how high should the fifth wheel plate be from ground to where king pin hooks? fifth wheel is going on a custom made bed and need to know about how high to mount. thank-you

asked by: Gary A

Expert Reply:

To measure the height that the fifth wheel head will need to be, on your custom made bed, you will need to park the vehicle and trailer on a fairly level surface and do some measuring.

Back your vehicle under the fifth-wheel trailer stopping when the center of the king pin is directly above the center of the fifth-wheel attachment jaws. Measure from the top of the bed on the truck to the base of the pin box on the trailer. This will give you the measurement needed to select a mounting height for the fifth-wheel hitch.

Most fifth-wheel hitches are height adjustable. If you are considering the Reese 20K M5 Fifth-Wheel Hitch, item # RP30928, the adjustment range is between 14 and 18 inches. You can then install the fifth-wheel accordingly. You will need to be sure that you have at least 6 inches of clearance between the underside of the trailer and any bedsides or rails on your custom bed for pitch and roll of the trailer when maneuvering.

Another thing you may want to consider is the distance from the center of the fifth-wheel and the rear of the custom bed. If the bed is going to be longer than 8 feet there may be issues with contact between the bed corners and the underside of the fifth-wheel trailer.

If you would like to send me the year, make and model of the truck you are using, I would be glad to send instructions which will provide installation location dimensions for your vehicle.

expert reply by: Robert G