Operating Principle

The transfer case delivers engine torque to the rear wheels and to the front wheels, when requested. The transfer case is mounted on the rear of the transmission assembly. The transfer case has an integrated low range gear reduction using the planetary gear set.

The transfer case has five different operating modes;

• Two Wheel Drive
• Four Wheel Drive - High Range
• Four Wheel Drive - Low Range
• Four Wheel Drive Auto
• Neutral (for recreational towing)

The transfer case is commanded via the mode select switch and the AWD module. The transfer case is electronically shifted via a shift motor mounted on the front of the transfer case housing. The transfer case is filled with lubricating oil which is circulated using a mechanical oil pump. The oil pump is fitted with a strainer to filter any debris.

In four wheel drive mode there is no speed differential between the front and rear axles. This can cause driveline windup when cornering on sealed surfaces.

The Advanced 4x4 with 4A Mode Transfer case is the center of the AWD system. It is a gearbox that attaches to the output of the transmission through a splined input at the transfer case. Torque from the transmission is transferred to the front and rear driveshaft depending on AWD mode.

The transfer case is equipped with an electronically controlled high torque capacity clutch which is located inside the case. This clutch is used to synchronize the speed of the front driveline with the rear driveline during 2WD to 4WD high (4H) or 4WD AUTO (4A) shifts. The clutch also provides torque to the front driveline in all 4WD modes. The transfer case is lubricated by a positive displacement fluid pump that channels fluid flow through holes in the rear output shaft.