To install a fifth-wheel hitch, find the appropriate mounting location, install the brackets to the frame, mount and wire the hitch and adjust the height. Exact mounting methods vary based on the manufacturer, so follow the provided instructions carefully if using a new hitch.
If possible, find a fifth-wheel hitch installation kit designed specifically for the vehicle for easy installation. If using a second-hand kit, ensure all pieces are present. Begin by mounting the kit's brackets to the frame of the truck so that a trailer pin would rest about an inch above the rear axle's center point. The brackets may be welded or bolted to the frame, but welding should be completed by a certified welder. If the truck has a plastic bed liner, remove the area of liner where the truck bed meets the rails. Never install the brackets directly to the truck bed as it is not built to hold the weight of a trailer and may disintegrate over time.
Mount and wire the hitch according to the kit's instructions, and lubricate the moving parts before use. If the hitch is adjustable for height, adjust the pin box up or down by replacing the bolts so that the hitch is level with the trailer. Keep an adequate amount of clearance between the trailer and the truck bed.