Graziano-F46 - Transfer Case

Transfer Case Description and Operation

Transfer Case Identification





The build variation of transfer case can be identified by the assembly part number (1) located on the rear output shaft housing of the transfer case. Refer to the table below for additional Build Variation information.

Transfer Case Build Variations

For 2010 model year the Cadillac SRX was built with multiple versions of the transfer case. Early 2010 model year vehicles were built with either first or second design Graziano supplied assemblies. First design Graziano transfer cases have a pressed into the housing vent assembly. Second design Graziano transfer cases have a bolt-in remote vent hose assembly. Vehicles built later in 2010 model year were produced with one of two versions of the American Axle Manufacturing (AAM) supplied transfer case based on engine and transmission configuration. Both the AAM transfer cases have a press-on clamp-retained remote vent hose assembly. The table below will help you to understand the brand of transfer case and content within. It is important to understand which variation is being serviced because of the different internal and external components and service parts for each. The AAM assembly can be used to replace an earlier design Graziano assembly providing the correct ventilation components are also used.





General Transfer Case Identification





The transfer case (1) is positioned in the right side of the vehicle and bolted to the transmission. Its primary function is to receive power from the transmission and transfer it using helical and hypoid gear sets to the rear differential via the propeller shaft. The internal intermediate shaft transfers power to the right-side front wheel.





The transfer case (1) is fully mechanical and is designed to transfer torque to the rear wheels. The transfer case contains four shafts for torque transfer. The input shaft transfers torque to the secondary or idler shaft. The idler shaft transfers torque and change in rotational direction to the pinion or rear output shaft. The intermediate shaft transfers torque to the right front wheel. The transfer case is sealed and the gears operate in hypoid lube.





During manufacture the transfer case (1) is filled with oil, which then does not require service interval replacement. The correct type of oil must be used without exception when filling. The incorrect type of oil could lead to transfer case damage. Refer to Adhesives, Fluids, Lubricants, and Sealers (Specifications).

Housing and Cover





The transfer case oil drain plug (1) is located at the front of the assembly.





The transfer case housing (1) and rear extension housing (2) are produced from a high-pressure cast aluminum alloy. A number of reinforcement ribs are fitted in suitable locations to strengthen the components. These reinforcement ribs constitute a vital part of the cooling for the transfer case. The transfer case rear extension housing is retained to the transfer case housing with bolts (3). Two dowel pins locate the rear extension housing to the transfer case housing. The mating surfaces of transfer case housing and rear extension housing are sealed by RTV type sealant.





The transfer case assembly is bolted to the transmission with four transfer case bolts. A locating bushing (2) on the transfer case housing ensures correct installation position. The sealing area between the transfer case housing and the transmission is sealed with serviceable O-ring (1). Two opposite radial seals seal the input shaft, and there is a weep hole in the transfer case housing between the radial seals.





A transfer case vent (2) is located on the top area of the transfer case housing. First design Graziano transfer cases have a pressed into the housing vent assembly. Second design Graziano transfer cases have a bolt-in remote vent hose assembly. Second design vent hose assemblies are routed to vent into the engine compartment. The oil drain plug (1) is magnetic. A mounting bracket retains the output end of the rear extension housing to the engine assembly.





The input and idler shafts are supported by tapered bearings (1). The bearing races are located in the transfer case housing and rear extension housing (2). Behind the bearing races are shims to provide the correct bearing preload.

The intermediate shaft is supported within the rear extension housing by a single-row sealed ball type bearing (3). The bearing is retained to the intermediate shaft via retaining rings.

The rear extension housing serves partly as a holder for the intermediate shaft bearing (3) and also as an attachment point for the transfer case to the engine.





A single lip type radial seal (1) is fitted in the rear extension housing at the input shaft to ensure oil from the transfer case does not seep out of the rear extension housing. The intermediate shaft seal (2) is located in the end of the input shaft.

Input Shaft





The function of the input shaft (3) is to transfer power from the transfer case. In one end the shaft is equipped with splines which are inserted into the transmission differential housing. The rotational speed of the input shaft is the same as the transmission output. Fitted in the transfer case housing are two opposite radial seals (5). The two input shaft seals are designed to restrict transmission oil from entering the transfer case as well as restrict transfer case oil from entering the transmission.

The opposite end of the input shaft is sealed by a single-lip seal that is installed into the rear extension housing. A second seal, the intermediate shaft seal is installed into the rear end of the input shaft. The intermediate shaft seal is designed to keep transmission and transfer case oil from mixing together.

The helical gear teeth of the input shaft are engaged to the helical gear teeth of the idler shaft.

The input shaft is mounted in two tapered roller bearings (2, 4). The bearings are given the correct preload at manufacture by means of shims fitted behind the bearing races in the housing and cover.

Idler Shaft





The idler shaft is located under the input shaft and is driven by the helical gear (2) on the input shaft. The idler shaft has a relatively large diameter and is hollow.

The idler shaft consists of a helical gear (2) and a hypoid gear (3). The helical gear is driven by the helical gear of the input shaft. The idler shaft hypoid gear (3) mates to the hypoid gear on the rear output shaft.

The idler shaft is mounted in two tapered roller bearings (1, 4). The bearings are given the correct preload at manufacture by means of shims being fitted behind the bearing races in housing and cover.

Rear Output Shaft Flange





The rear output shaft housing (2) is bolted to the transfer case housing with 7 bolts (1) and is sealed to the transfer case housing with a serviceable O-ring (4) seal. A shim (3) adjusts the rear output shaft helical gear to the helical gear of the idler shaft. The rear output shaft flange is hollow and is equipped with internal splines. The splines of the propeller shaft are mated to the rear output shaft. The spline of the propeller shaft is equipped with a spring-loaded retaining ring which retains the propeller shaft in the rear output shaft flange.