FORD 2010 F-550 v.2 - Manual (Page 290)

WARNING: 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.
Using the Electronic Shift On the Fly (ESOF) 4x4 system
(if equipped)
Positions of the electronic shift system
Note: Some noise may be heard as the 4WD system shifts or engages.
This is normal.
2WD – For general on-road driving. Sends power to the rear wheels only.
4x4 HIGH – For winter and off-road conditions. Sends power to front
and rear wheels. This mode is not intended for use on dry
pavement.
4x4 LOW – For low-speed off-road applications that require extra power
such as steep grades, deep sand or pulling a boat out of the water. Sends
power to front and rear wheels. This mode is not intended for use on
dry pavement.
Shifting from 2WD to 4x4 HIGH
Rotate the 4x4 control to the 4x4
HIGH position at speeds up to
55 mph (88 km/h).
• The electronic shift 4x4
system is designed to engage
4x4 HIGH when the vehicle is
moving. If shifted to 4x4
HIGH while at complete stop,
4x4 may not engage and the
4x4 indicator may flash
continuously until the vehicle
is allowed to move at a speed above 1 mph (1.6 km/h).
• Do not shift into 4x4 HIGH with the rear wheels slipping.
Driving
290
2010 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)