Transfer Case

WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Cutaway View Of Transfer Case

Courtesy of GENERAL MOTORS CORP.

The transfer case assembly consists of a four-piece aluminum housing, an input helical gear assembly (carrier) (1), an idler helical gear (2), and a hypoid bevel gear set which consists of two shaft assemblies supported by tapered roller bearings (4). The design of this component changes power output from transverse to longitudinal and also positions the propeller shaft assembly near the centerline of the vehicle. The propeller shaft assembly (mated to the output flange of the transfer case) is constantly rotating and spins at a rate equal to an average of the two front wheels.

The transfer case is mated to the right side of the 4T65-E automatic transmission. Two types of lubricant are used within the transfer case: automatic transmission fluid for the three helical gear set and a unique hypoid gear oil for the bevel gears. Two oil seals, internal to the case (3) separate the two types of fluid.