Patent ID: 8419577

Claim:
A torque transmitting system for an all-wheel drive motor vehicle, comprising: a front differential drivingly connected to a front set of wheels; a rear differential drivingly connected to a rear set of wheels; an interaxle differential actuated by a clutch, drivingly connected to said front and rear differentials; an auxiliary gear train drivingly interconnecting said interaxle differential and said clutch for producing a selected rotational speed difference in said clutch; a first clutch drivingly interconnecting a change speed gear of said vehicle and said front differential; a second clutch drivingly interconnecting said charge speed gear and said rear differential; an overriding drive comparable with said rear differential and selectively actuated by a set of clutches, operatively connected to said set of rear wheels, operable to vary the ratios of torque transmitted to said set of rear wheels; and an electronic control device programmed to determine whether an oversteering tendency of the all-wheel drive motor vehicle exceeds a first defined threshold, wherein the oversteering tendency is detected by one selected from the group consisting of a steering angle of the all-wheel drive motor vehicle, a yaw rate of the all-wheel drive motor vehicle, an acceleration of the rear set of wheels, and combinations thereof; upon detection of the oversteering tendency, selectively actuating selected ones of said clutches to perform one selected from the group consisting of reducing the drive torque of the rear differential, increasing the drive torque of the front differential, and combinations thereof; to determine whether an understeering tendency of the all-wheel drive motor vehicle exceeds a second defined threshold, wherein the understeering tendency is detected by one selected from the group consisting of a steering angle of the all-wheel drive motor vehicle, a yaw rate of the all-wheel drive motor vehicle, an acceleration of the rear set of wheels, and combinations thereof; and upon detection of the understeering tendency, selectively actuating selected ones of said clutches to perform one selected from the group consisting of reducing the drive torque of the front differential, increasing the drive torque of the rear differential.