Transfer Case: Description and Operation: Overview

Four-Wheel Drive Systems

OVERVIEW
The power transfer unit is located at the rear of the engine and is attached directly to the transmission casing. A bracket on the power transfer unit attaches the unit to the engine cylinder block.
Two unique power transfer units are used for the petrol and diesel engines and the units cannot be interchanged. The unit casings and the breather outlet location differ between the petrol and diesel derivatives due to engine block fitment requirements, however the internal components are the same in both units.
The unit transfers the output from the transmission and distributes it to the rear wheels via a drive shaft to the rear on-demand coupling and differential. The front half shafts are driven from the transmission differential, not the power transfer unit. The unit has an internal pre-load system. This allows the pinion output seal to be changed in-service without disturbing the bearing pre-load.
The power transfer unit has the following features:
- 1500 Nm torque capacity
- 2.58:1 output ratio to the drive shaft
- Oil filled for life
- Remote breather.