GM Service Manual Online
For 1990-2009 cars only

Transfer Case


Object Number: 166989  Size: LF
(1)Front Drive Clutch
(2)Drive Sprocket
(3)Four-Wheel Drive Switch
(4)Gearshift Control Lever
(5)Rear Output Shaft
(6)Speedometer Driven Gear
(7)Drive Chain
(8)Front Output Shaft
(9)Counter Gear
(10)Countershaft
(11)Input Gear
(12)Reduction Clutch Sleeve
(13)Low Output Gear

In four wheel drive models, the transfer case, located at the rear of the transmission, is responsible for transferring engine torque to the front and rear wheels on vehicles equipped with four-wheel drive. The transfer case contains an input gear, countershaft and counter gear, rear output shaft, low output gear and a front output shaft (for front drive) connected and driven by a drive chain.

The transfer case gearshift control lever can be placed in four positions: 4H (direct connection with the input gear, counter gear and low output gear), N (by way of the reduction clutch sleeve located between the input gear and the low output gear) and 2H (high speed to the rear wheels only). The front drive shift fork mechanism also has an auxiliary spring to ensure a smooth shift from 4H to 2H.

In two-wheel drive models (4-speed automatic transmission only) the transfer case, located at the rear of the transmission, is responsible for transferring engine torque to the rear wheels. The transfer case contains an input gear, countershaft and counter gear, rear output shaft and low output gear. This transfer case is different from that of the four-wheel drive models, it is not equipped with a gearshift control lever for 4H, 4L, 2H and N positions.