2009 Ford F450 Super Duty Crew Cab Owner's Manual - Page 302

Driving 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. Shifting from 4x4 HIGH to 2WD Rotate the 4x4 control to 2WD at any forward speed. Disengagement of the transfer case and front hubs may be delayed due to torque bind which is caused by driving on dry hard surfaces or performing tight turns while using the 4x4 system. • You do not need to operate the vehicle in R (Reverse) to disengage your front hubs, but it will eliminate any torque bind and allow the system to immediately disengage. Shifting from 4x4 HIGH to 4x4 LOW • If the range shift requirements are not met, the 4x4 Low indicator will flash continuously. 1. Bring the vehicle to a complete stop. 2. Place the gearshift in N (Neutral). If the vehicle is equipped with a manual transmission, also depress the clutch pedal. 302 2009 F-250/350/450/550 (f23) Owners Guide, 3rd Printing USA (fus)