Four Wheel Drive (4WD) Systems

Four Wheel Drive (4WD) Systems

The All-Wheel Drive (AWD) system consists of the following:

- Power Transfer Unit (PTU)

- Rear driveshaft

- AWD (All-Wheel Drive) relay module

- Rear axle with coupling device

Torque from the engine is transferred through the transaxle to the PTU (Power Transfer Unit). This torque is transferred from the driveshaft to the rear axle, which drives the rear halfshafts. The AWD (All-Wheel Drive) system, also referred to as an Active Torque Coupling (ATC) system, is always active and requires no driver input.

The AWD (All-Wheel Drive) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is delivered to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the AWD (All-Wheel Drive) system increases torque to the rear wheels to prevent or control wheel slip. When the AWD (All-Wheel Drive) system is functioning properly, there should be no perceived speed difference between the front and rear axles when launching or driving the vehicle on any uniform surface. Traction should be similar to a part time Four-Wheel Drive (4WD) system in 4H (4X4 HIGH), but have no binding in turns.

Serviceable components of the PTU (Power Transfer Unit) are limited to the output shaft seal and flange, intermediate shaft seal and deflector, and the PTU (Power Transfer Unit) transaxle compression seal. No internal components are serviced. There should be no need to remove the PTU (Power Transfer Unit) cover. If any of the internal geared components, bearings, case cover or shafts are worn or damaged, a new PTU (Power Transfer Unit) must be installed.