FORD 2013 F-550 v.1 - Manual (Page 212)

Using the Electronic Shift on the Fly 4WD system (If Equipped)
2H (2WD) - For general on-road
driving. Sends power to the rear
wheels only and should be used for
street and highway driving. Provides
optimal smoothness and fuel
economy at high speeds.
4H (4X4 HIGH) - Used for extra
traction such as in snow or icy
roads or in off road situations. This
mode is not intended for use on dry
pavement.
4L (4X4 LOW) - Uses extra gearing to provide maximum power to all
four wheels at reduced speeds. Intended only for off-road applications
such as deep sand, steep grades, or pulling heavy objects. 4L (4x4 low)
will not engage while the vehicle is moving above 3 mph (5 km/h); this is
normal and should be no reason for concern. Refer to Shifting to/from
4L (4x4 low) for proper operation.
Shifting between system modes
Note: Momentarily releasing the accelerator pedal while performing a
shift will improve engagement/disengagement times.
Note: Do not perform this operation if the rear wheels are slipping.
Note: Some noise may be heard as the system shifts or engages; this is
normal.
Note: 4X4 high mode is not intended for use on dry pavement.
You can move the control from 2H or 4H at a stop or while driving. The
information display may display a message indicating a 4X4 shift is in
progress. Once the shift is complete the message center will then display
the system mode selected.
If SHIFT DELAYED PULL FORWARD is displayed in the information
display during the mode shift, transfer case gear tooth blockage is
present. To alleviate this condition, place the transmission in a forward
gear and move the vehicle forward approximately 5 feet (2 meters) to
allow the transfer case to complete the mode shift.
2H
4H
4L
Four-Wheel Drive (If Equipped) 211
2013 F-250/350/450/550 (f23)
Owners Guide gf, 1st Printing
USA (fus)