FORD 2010 F-550 v.2 - Manual (Page 285)

• For proper operation, make sure that each hub is fully engaged
and that both hub locks are set to the same position (both set
to LOCK or both set to FREE). To engage LOCK, turn the hub
locks completely clockwise; to disengage the hubs (FREE),
turn the hub locks completely counterclockwise.
• The vehicle should not be driven in 4X4 High or 4X4 Low
modes with the hub locks set to FREE as this condition may
damage driveline system components.
• Some vehicles may be equipped with wheel ornaments that cover the
4x4 manual hub lock. These ornaments must be removed to access
the manual hub locks.
Electronic Shift On the Fly (ESOF) 4x4 system (if equipped)
If equipped with the electronic shift 4WD System, and the
instrument panel control is moved to 4X4 LOW while the vehicle
is moving above 5 mph (8 km/h), the system will not engage and
no damage will occur to the 4WD system. Before 4X4 LOW can be
engaged, the vehicle speed must be below 5 mph (8 km/h) with
the transmission in N (Neutral). If your vehicle is equipped with
a manual transmission, the clutch pedal also must be depressed.
The 4x4 Low indicator will flash continuously until these actions
are performed by the user. This vehicle is equipped with a
non-synchronous low range gearset which will not allow the
transfer case to shift into 4X4 LOW if vehicle speed is above
5 mph (8 km/h). It is recommended that a shift to 4X4 LOW is
performed while the vehicle is rolling at a speed below 5 mph
(8 km/h).
The 4WD system:
• provides 4x4 High engagement and disengagement while the vehicle is
moving.
• is operated by a rotary control located on the instrument panel that
allows you select 2WD, 4x4 High or 4x4 Low operation.
• uses auto-manual hub locks that can be engaged and disengaged
automatically based on the 4x4 mode selected.
Driving
285
2010 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)