Transfer case (VG) function - GF28.10-P-0002B

MODEL 163 

Design 

The transmission housing (20) and transmission cover (21) are made of a metal alloy and are screwed together.

The input shaft (1) functions directly as a sun gear for the single planetary gear set (15) and is connected to the output shaft of the manual or automatic transmission. The ring gear (16) of the single planetary gearset is fixed to the transmission housing.

Input shaft (1), intermediate shaft (2) and output shaft/rear-wheel drive (3) are slotted into one another, are carried in ball bearings and lie in a single plane in the housing.

The single planetary gearset shifts a long ratio (road ratio) or short ratio (off-road ratio).

A double planetary gearset (8) and a sprocket (9) are positioned on the output shaft/rear-wheel drive (3).

The output shaft here is also designed as a sun gear for the double planetary gearset.

The sprockets (9) and link chain (5) drive the output shaft/front-wheel drive (4) which is carried in ball bearings in the housing. The output shaft and output flange/front-wheel drive are one-piece components. The range selector motor (6) screwed onto the outside of the transmission cover shifts a road ratio or off-road ratio. The oil pump (7) is driven by the intermediate shaft.

Function 

When driving straight ahead, the engine torque is distributed between the front and rear axles in the ratio 50:50.

The double planetary gearset (8) functions as a differential ( Central differential ) between the front and rear axles.

The engine torque is transferred via the single planetary gearset (15) to the intermediate shaft (2). Either a step-up ratio (1:1) or a step-down ratio (2.64:1) is selected on the intermediate shaft according to the position of the reduction hub (11). A spring (14) on the shift shaft (12) holds the shift fork (13) is the position for the road ratio 1:1.

If the off-road reduction gear is activated, the range selection motor (6) moves the shift fork against the force of the spring which in turn, moves the reduction hub axially on the intermediate shaft.

Power flow road ratio 1:1 

The reduction hub (11) is in the left position. The torque from the input shaft (1) is therefore transferred directly to the intermediate shaft (2).

Power flow off-road reduction gear ratio 2.64:1 

The reduction hub (11) is in the right position. The torque from the input shaft (1) is therefore transferred to the intermediate shaft (2) via the planet gears (18) and planet carrier (19).

The fixed ring gear (16) creates a step-down ratio to slow speeds.

	Task	To distribute the power flow permanently to the front and rear axles in a certain ratio.
	Transfer case oil supply, function	Model 163
	Transfer case control module, location		GF28.19-P-3100-01A
	Transfer case range selection motor, location		GF28.19-P-3400-01A
	"Low Range" switch, location		GF28.19-P-1003-01A
	Transfer case "Low Range" indicator lamp, location		GF28.19-P-3300-01A