In this four-wheel drive vehicle, the engine and transmission are mounted longitudinally at the front. Propeller shafts transfer the drive from a transfer case on the rear of the transmission, to final drive units at front and rear.
The beam type axle housings enclose the crownwheel and pinion and the differential gears and the offset propeller shafts mean the drive is transmitted through the short and long axle shafts to the driving wheels.
A third differential is in the transfer case, between the front and rear output shafts to the final drive units.
This allows for any difference in speed between the front and rear output shafts when the vehicle drives in high range. In addition, a viscous coupling limits the third differential action if any of the drive wheels spin. Torque is automatically transferred to wheels that are not spinning.
In extremely slippery conditions, engaging low range automatically activates a differential lock to prevent third differential operation.
Source: CDX Global
