FORD 2013 F-550 v.3 - Manual (Page 223)

Parking
WARNING: If the parking brake is fully released, but the brake
warning lamp remains illuminated, the brakes may not be
working properly. See your authorized dealer.
WARNING: Always set the parking brake fully and make sure
the gearshift is latched in P (Park). Turn the ignition to the off
position and remove the key whenever you leave your vehicle.
On some 4WD vehicles, when the transfer case is in the N (Neutral)
position, the engine and transmission are disconnected from the rest of
the driveline. Therefore, the vehicle is free to roll even if the automatic
transmission is in P (Park) or the manual transmission is in gear. Do not
leave the vehicle unattended with the transfer case in the N (Neutral)
position. Always set the parking brake fully and turn off the ignition
when leaving the vehicle.
Maintenance and modifications
The suspension and steering systems on your vehicle have been designed
and tested to provide predictable performance whether loaded or empty
and durable load carrying capability. For this reason, Ford Motor Company
strongly recommends that you do not make modifications such as adding or
removing parts (such as lift kits or stabilizer bars) or by using replacement
parts not equivalent to the original factory equipment.
Any modifications to a vehicle that raise the center of gravity can make
it more likely the vehicle will roll over as a result of a loss of control.
Ford Motor Company recommends that caution be used with any vehicle
equipped with a high load or device (such as ladder racks or pickup box
cover).
Failure to maintain your vehicle properly may void the warranty, increase
your repair cost, reduce vehicle performance and operational capabilities
and adversely affect driver and passenger safety. Frequent inspection of
vehicle chassis components is recommended if the vehicle is subjected to
heavy off-road usage.
222 Four-Wheel Drive (If Equipped)
2013 F-250/350/450/550 (f23)
Owners Guide gf, 3rd Printing, December 2012
USA (fus)