Transfer Case - Power Transfer Unit (PTU)

Transfer Case - Power Transfer Unit (PTU)

System Operation

The PTU (Power Transfer Unit) is a gearbox attached to the transaxle. The RH (Right Hand) intermediate shaft passes through the PTU (Power Transfer Unit) and engages the differential side gear, similar to FWD (Front Wheel Drive) applications. The PTU (Power Transfer Unit) directs power to the rear driveshaft through a helical gear spline coupled to the transaxle differential case, a helical gear drop (idler gear) and hypoid/helical ring gear assembly and pinion set. The PTU (Power Transfer Unit) is sealed from the transaxle and has its own oil sump.

The internal components are not serviceable. Do not remove the cover of the PTU (Power Transfer Unit). If any of the geared components, bearings, case cover or internal shafts are worn or damaged, a new PTU (Power Transfer Unit) must be installed.

The following components of the PTU (Power Transfer Unit) are serviceable:
- Compression seal
- Cover seal
- Intermediate shaft seal and deflector
- Output shaft seal and flange
- Input shaft seals

Heat Protection Mode

During very extreme off-road operation, the AWD (All-Wheel Drive) system utilizes a heat protection mode to protect the ATC (Active Torque Coupling) solenoid (part of rear axle) from damage. If the system detects an overheat condition, it enters a locked mode. If the heat in the system continues to rise once in the locked mode, the 4X4 control module disables the ATC (Active Torque Coupling) solenoid. Before continuing with normal operation, allow the system to cool down at least 10 minutes with the ignition switch in the ON position.