1997 Ford F250 Owner's Manual - Page 163

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. RWARNING 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. Four-Wheel Drive (4WD) System (If equipped) When you select the 4WD mode, your light truck uses all four wheels to power itself. This increases traction, enabling you to drive your 4x4 over terrain and road conditions two-wheel drive vehicles cannot. Power is supplied to all four wheels through a transfer case that allows you to select four-wheel drive when necessary. Methods for engaging and disengaging 4WD and low range will depend on which system your vehicle has. 163