Principles of Operation

The AWD system may be referred to as a 4WD system in other service information and owner literature or messages located on the message center.

The power transfer unit is a gearbox that is attached to the transmission. The RH intermediate shaft passes through the power transfer unit and engages the differential side gear as in normal FWD applications. The power transfer unit directs power to the rear driveshaft through a helical gear spline coupled to the transmission differential case, hypoid/helical ring gear assembly and pinion set. The power transfer unit is sealed from the transmission and has its own oil sump.

Serviceable components of the power transfer unit are limited to the output shaft seal and output flange deflector, intermediate shaft seal, input shaft seal, cover seal and the power transfer unit-transmission compression seal. The internal components are not serviced. If any of the geared components, bearings, case cover or internal shafts are worn or damaged, a new power transfer unit must be installed.

Heat Protection Power Transfer Unit 

During off-road operation or heavy trailer towing the AWD system may implement a heat protection mode to protect the power transfer unit from damage. The AWD system will reduce commanded torque to half as the temperature approaches its limit. Once the temperature limit is reached, then 2WD only is commanded.

For concerns with the AWD system or ATC, REFER to: Four-Wheel Drive Systems .