DRIVE LINE OPERATION METHOD

The invention concerns a method for operating a vehicle drive train, whereby the drive train comprises a drive unit, a transmission, and an all-wheel splitter having an automatically operating clutch, positioned between the transmission and the output, whereby the clutch of the all-wheel splitter is operated in a continuous slip mode and in a way that it is splits a transmission output torque in the sense of a variable torque distribution to driven axles of the output, whereby the split of the transmission output torque to the driven axles, is performed by a control unit, being implemented into the all-wheel drive strategy in a way that the transmission output torque, less a predetermined nominal torque being set by the all-wheel drive strategy, is transferred to a first axle, and the nominal torque is transferred to a second axle. In this invention, when defined operating conditions are met, a clutch monitoring function is activated and the nominal torque, set by the all-wheel strategy, is replaced by a torque definition of the clutch monitoring function in a way that, first, the torque which is transferred by clutch to the second driven axle, is increased, then being kept constant, and thereafter again reduced.