The NV231 and 241 are part time transfer cases with a low-range gear system. They have three operating ranges plus a Neutral position. The low range (4L) position provides a gear reduction ratio of 2.72:1 for increased low speed torque capability. NV241 operating ranges are: 2-high, 4-high, and 4-low. Transfer case operating ranges are selected with a floor-mounted shift lever. The shift lever is connected to the transfer case range lever by an adjustable linkage rod. A straight line shift pattern is used.
On the NV transfer case, the gear cases, retainer, and extension are all of aluminum. Drive sprockets and an interconnecting chain are used to transmit engine torque to the front and rear propeller shafts. The mainshaft, input gear, and front output shaft are supported by ball and needle bearings.
A synchro mechanism consists of a brass stop ring, synchro hub with three struts and two retaining springs, and the sliding clutch. The synchro components allow the transfer case to be shifted between 2H and 4H ranges while the vehicle is in motion. However the vehicle must be stopped or moving very slowly to shift into 4L range. Four wheel high and low ranges are undifferentiated. The transfer case is not designed for continuous operation in 4WD range on hard or paved roads. 4WD ranges are recommended for off road operation, or on snow covered or similar low traction surfaces.
EDIT: [Info courtesy of Dodgeram.org]