Ford 2010 F-350 Owner's Manual page 255

WARNING: Towing trailers beyond the maximum tongue weight
exceeds the limit of the towing system and could result in
vehicle structural damage, loss of vehicle control and personal injury.
Weight-distributing hitch
When hooking-up a trailer using a load-equalizing hitch, always use the
following procedure:
1. Park the unloaded vehicle on a level surface. With the ignition on and
all doors closed, allow the vehicle to stand for several minutes so that it
can level.
2. Measure the height of a reference point on the front and rear bumpers
at the center of the vehicle.
3. Attach the trailer to the vehicle and adjust the hitch equalizers so that
the front bumper height is within
After proper adjustment, the rear bumper should be no higher than in
Step 2.
WARNING: Do not adjust a weight-distributing hitch to any
position where the rear bumper of the vehicle is higher than it
was before attaching the trailer. Doing so will defeat the function of
the weight-distributing hitch, which may cause unpredictable handling,
and could result in serious personal injury.
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.
If you use a rental trailer, follow the instructions that the rental agency
gives to you.
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. The trailer brakes must meet local and Federal
regulations.
2010 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)
Tires, Wheels and Loading
1 ⁄ " (13 mm) of the reference point.
2
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