Transfer Case: Description and Operation

Four Wheel Drive (4WD) Systems

The transfer case is connected to the transmission output shaft and is responsible for transmitting power through the rear drive shaft to the rear axle, and through the front drive shaft to the front axle. There are 2 types of transfer cases: mechanical shift and electronic shift.

The mechanical-shift Four-Wheel Drive (4WD) system consists of the following:

- Transfer case
- Transfer case shift lever
- Manual locking hubs (hublocks)
- 4WD indicators
- Shift linkage

The electronic-shift 4WD system consists of the following:

- Transfer case
- 4X4 control module
- Mode Select Switch (MSS)
- Gearmotor encoder assembly
- Automatic locking hubs (hublocks)
- Pulse Vacuum Hublock (PVH) solenoid and vacuum lines