2023 Ford Expedition Owner’s Manual — How Does Four-Wheel Drive Work

Using the 1-Speed Automatic Four-Wheel Drive System

The 1-speed automatic four-wheel drive system utilizes an electronically controlled on-demand 1-speed transfer case. This system monitors various vehicle sensory inputs to provide an increased level of performance. This system offers the driver two-wheel drive high, four-wheel drive auto and four-wheel drive high as available modes of operation via the selectable drive mode switch. When you select four-wheel drive auto the system continuously varies power to the front wheels for optimum performance for all on-road conditions. When you select four-wheel drive high the system provides power to the front and rear wheels for use in off-road or slippery conditions such as deep snow, sand or mud. There is further information on driving in unique driving conditions.   See   Driving Hints. 

Using the 2-Speed Automatic Four-Wheel Drive System (If Equipped)

The 2-speed automatic four-wheel drive system utilizes an electronically controlled on-demand 2-speed transfer case. This system monitors various vehicle sensory inputs to provide an increased level of performance. This system offers the driver two-wheel drive high, four-wheel drive auto, four-wheel drive high, and four-wheel drive low as available modes of operation. When you select four-wheel drive auto the system continuously varies power to the front wheels for optimum performance for all on-road conditions. When you select either four-wheel drive high or four-wheel drive low with the appropriate drive modes, the four-wheel drive system provides electronically locked power to the front and rear wheels for use in off-road or slippery conditions such as deep snow, sand or mud. Selecting four-wheel drive low also provides additional gearing for increased torque multiplication for conditions like deep sand, snow, steep slopes, or pulling heavy objects.   See   Selecting a Four-Wheel Drive Mode.  Additionally, the system is capable of recreational flat towing by putting the transfer case into neutral (N).
  See   Recreationally Towing Your Vehicle - 4x4. 

There is further information on driving in unique driving conditions.  See   Driving Hints.