Description of 4WD Control System Operation

Description of 4WD Control System Operation

Instead of the transfer shift lever assembly, the transfer position (4H, 4H-lock, N and 4L-lock) is shifted automatically by operating the transfer switch.

The 4WD control module operates the transfer shift actuator according to the transfer switch operation.

4H (4WD High) Position

The driving force from the transmission is transmitted to the transfer input gear. As the center differential assembly and transfer input gear are engaged via the reduction shift sleeve at this time, the driving force transmitted from the transfer input gear to the rear output shaft rotates them at the same speed.

Also, driving force from the center differential assembly is transmitted to the front drive sprocket through differential side gear No.2 and front drive clutch hub. Then, the front drive sprocket rotates the front output shaft via the drive chain.










4H-lock (4WD High Center Differential Lock) Position

When 4H-lock position is selected from 4H position by turning the transfer switch, the transfer shift control actuator motor runs and shift cam rotates in the arrow direction "A". The shift cam shifts the differential lock shift fork in the arrow direction "B", and the differential lock clutch sleeve also moves in the arrow direction "B".

The driving force from the transmission is transmitted from the transfer input gear to the rear output shaft, as in the case of 4H position. Also, as the front drive clutch hub and front differential lock clutch hub are engaged via differential lock clutch sleeve, the driving force from the input gear is locked and transmitted to the rear output shaft.










N (Neutral) Position

When N position is selected from 4H position by turning the transfer switch, the transfer shift control actuator motor runs and shift cam rotates in the arrow direction "A". The shift cam shifts the High / Low shift fork in the arrow direction "B", and the reduction shift sleeve moves in the arrow direction "B". Also, the shift cam shifts the differential lock shift fork in the arrow direction "C", and the differential lock clutch sleeve also moves in the arrow direction "C".

The driving force from the transmission is transmitted to the transfer input gear. However, as the reduction shift sleeve is not engaged with the transfer input gear and low gear, the driving force is not transmitted to the rear output shaft and front output shaft.










4L-lock (4WD Low Center Differential Lock) Position

When 4L-lock position is selected from 4H-lock position by turning the transfer switch, the transfer shift control actuator motor runs and shift cam rotates in the arrow direction "A". The shift cam shifts the High/Low shift fork in the arrow direction "B", and the reduction shift sleeve moves in the arrow direction "B". Also, the shift cam shifts the differential lock shift fork in the arrow direction "C", and the differential lock clutch sleeve also moves in the arrow direction "C".

The driving force from the transmission is transmitted from the transfer low gear, through the transfer input gear and transfer counter gear with the speed reduced. At this time, as the center differential assembly case and transfer low gear are engaged via reduction shift sleeve, the driving force is transmitted to the rear output shaft.

The driving force of the rear output shaft makes the front output shaft rotate via the differential lock clutch sleeve as in the case of 4H-lock position.