4HI and AWD Power Flow
In the 4 HI mode, the power flow to the rear propshaft is the same as it is in the 2 HI mode. To deliver power flow to the front propshaft during the 4 HI position, the transfer control module commands the encoder motor to apply the clutch to a calibrated torque. The encoder motor turns the control actuator lever shaft (8). A brake in the encoder motor holds the control actuator shaft (8) in the full clutch position. The control actuator lever shaft (8) is cam designed and the cam action moves the clutch lever (4). The clutch lever (4) pivots on the control lever pivot studs and moves toward the clutch apply plate, to engage the clutch. As more pressure is applied to the clutch apply plate, the clutch discs are compressed. Using inner clutch discs, which are engaged with the clutch hub (3), and the outer clutch discs, which are engaged with the clutch housing, the power flow is delivered to the clutch housing. The clutch hub (3) is splined to the rear output shaft (5), and the clutch housing rotates on a needle bearing on the rear output shaft (5). The chain drive sprocket is splined to the clutch housing. The power flows from the drive sprocket, through the chain, to the chain driven sprocket. The driven sprocket is splined to the front output shaft (9). The power flow is delivered to the front propshaft through the front output shaft (9).
During the Auto 4WD mode, the power flow is the same as it is in the 4 HI mode. Except, during the Auto 4WD mode, the encoder motor rotates the control actuator shaft lever to the learned adapt ready positions. Rotating the control actuator to the various positions changes the clutch torque level. When a difference of front propshaft to rear propshaft speed is recognized, the transfer case control modules commands for more, or less clutch torque.