Internal Components

Fig 1: Power Transfer Unit Case Internal Components

Courtesy of GENERAL MOTORS COMPANY

The OD splines of the input shaft (4) are mated to the ID splines of the transmission output shaft. Power and torque are transferred from the input shaft (2) to the idler shaft (6) via a helical gear set. A second gear set, the hypoid gear set transfers power and torque from the idler shaft to the rear output shaft (1). The propeller shaft is mated to the rear output shaft providing power and torque to the rear drive axle. The OD splines of the intermediate drive shaft (3) mate to the ID splines of the transmission carrier assembly and provide power and torque to the right front axle shaft and wheel.

Gear tooth clearances and bearing preloads are maintained by shims located behind the bearing races. The housings, internal gears, and bearings are not serviceable components. If housing, gear set, or bearing damage occurs, the assembly must be replaced.

1. Power Transfer Unit Rear Output Shaft
2. Power Transfer Unit Input Shaft
3. Power Transfer Unit Intermediate Drive Shaft-to-Transmission Splines
4. OD Splines of the Input Shaft
5. Power Transfer Unit Input Shaft Seal- Front
6. Power Transfer Unit Idler Shaft
7. Power Transfer Unit Input Shaft Seal- Rear
8. Power Transfer Unit Shift Actuator Gear
9. Power Transfer Unit Shift Actuator Locker
10. Power Transfer Unit Cover-to-Intermediate Drive Shaft Seal-at-Extension Housing
11. Power Transfer Unit Intermediate Drive Shaft