See also:

Shifting Into Four-Wheel Drive Low
When Four-Wheel Drive Low is engaged, vehicle speed should be kept below 72 km/h (45 mph). Extended high-speed operation in Four-Wheel Drive Low may damage or shorten the life of the drivetrain. To ...

Range Selection Mode (Allison® Transmission or Hydra-Matic® 6-Speed Transmission)
The vehicle may have a Range Selection Mode. The Range Selection Mode helps control the vehicle's transmission and vehicle speed while driving down hill or towing a trailer by letting you select a d ...

If the Vehicle Is Stuck
Slowly and cautiously spin the wheels to free the vehicle when stuck in sand, mud, ice, or snow. If stuck too severely for the traction system to free the vehicle, turn the traction system off an ...