Ford 2003 Explorer Owner's Manual page 120

Driving
Do not exceed the GVWR or the GAWR specified on the
certification label.
Towing trailers beyond the maximum recommended gross trailer
weight exceeds the limit of the vehicle and could result in
engine damage, transmission damage, structural damage, loss of vehicle
control, vehicle rollover and personal injury.
Preparing to tow
Use the proper equipment for towing a trailer and make sure it is
properly attached to your vehicle. See your dealer or a reliable trailer
dealer if you require assistance.
Hitches
Do not use hitches that clamp onto the vehicle bumper. Use a load
carrying hitch. You must distribute the load in your trailer so that 10% of
the total weight of the trailer is on the tongue.
Use a frame-mounted weight distributing hitch for trailers over
1,588 kg (3,500 lb).
Safety chains
Always connect the trailer's safety chains to the frame or hook retainers
of the vehicle hitch. To connect the trailer's safety chains, cross the
chains under the trailer tongue and allow slack for turning corners. Do
not attach safety chains to the bumper.
Trailer brakes
Electric brakes and manual, automatic or surge-type trailer brakes are
safe if installed properly and adjusted to the manufacturer's
specifications.
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.
The braking system of the towing vehicle is rated for operation at the
GVWR not GCWR.
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