Dodge 2007 DR Ram Owner's Manual page 322

322 STARTING AND OPERATING
When additional traction is required, the transfer case
4WD HI and 4WD LO positions can be used to lock the
front and rear driveshafts together and force the front
and rear wheels to rotate at the same speed. This is
accomplished by rotating the 4WD Control Switch to the
desired position - see Shifting Procedure section for
specific shifting instructions. The 4WD HI and 4WD LO
positions are designed for loose, slippery road surfaces
only. Driving in the 4WD HI and 4WD LO positions on
dry hard surfaced roads may cause increased tire wear
and damage to the driveline components.
Neutral Button