1996 Ford F350 Owner's Manual - Page 196

Operating in 2H with the hubs in the LOCK position increases fuel consumption, noise, vibration, and wear. For prolonged 2H operation on dry pavement, set the manual locking hubs to the FREE position. To shift between 4H and 4L: Stop the vehicle and place the automatic transmission into NEUTRAL or depress the clutch on manual transmission vehicles. Push the transfer case shift knob down (toward the ground) and at the same time pull or push the lever straight forward or rearward (depending on the desired position 4H or 4L) in order to shift the transfer case. This shift should be with one continuous motion without pausing in the N (neutral) position. Pausing in the neutral position can result in gear clash and difficult shifting. If, while shifting between 4H and 4L, the transfer case gets stuck in the N (neutral) position or is difficult to shift into either 4H or 4L, it may be necessary to let the vehicle roll slightly and/or turn off the engine (particularly on vehicles equipped with automatic transmission). To shift to N (neutral) from either 4H or 4L To shift into N (neutral), stop the vehicle and engage the parking brake. Place the automatic transmission into NEUTRAL or depress the clutch on manual transmission vehicles. From either the 4H or 4L position, push the transfer case shift knob down (toward the ground) and at the same time move the transfer case shift lever to the N (neutral) position. The N (neutral) position should only be used for vehicle towing or transfer case mounted PTO use (transfer case PTO opening available on F-350 only). 194