Ford F series Owner's Manual page 210

Hitches
Do not install a single or multi-clamp type
bumper hitch, or a hitch which attaches to the
axle. Underbody mounted hitches are acceptable
if installed properly. Follow towing instructions
of a reputable rental agency.
Whenever a trailer hitch and hardware are
removed, make sure all mounting holes in the
underbody are properly sealed to prevent
noxious gases or water from entering.
Step bumper (If equipped)
The optional step bumpers have a built-in hitch
and only requires a ball with a one inch shank
diameter. This step bumper has a Class III
capability (5000 lb/2,270 kg trailer weight and
500 lb/680 kg tongue weight).
Safety chains
Always use safety chains between your vehicle
and trailer. Cross chains under the trailer tongue
and allow slack for turning corners. Connect
safety chains to the vehicle frame or hook
retainers. Never attach chains to the bumper.
Trailer Brakes
Separate trailer brakes are required on most
towed vehicles weighing over 1,500 lb (680 kg).
Do not connect a trailer's hydraulic brake
system directly to your vehicle's brake
system. Your vehicle may not have
enough braking power and your chances
of having a collision greatly increase.
210
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