The drive train of an all-wheel drive vehicle comprises a transfer case that is connected to the motor block, a driven front axle, a driven rear axle, drive shafts and a control device. To vary the torque distribution between the axles from 0 to 100% the transfer case has a drive-through shaft that has a drive connection both with the motor block and the drive shaft that leads to the rear axle. The drive-through shaft includes a drive connection with the drive shaft that leads to the front axle by a first friction clutch that determines the torque applied to the front axle. The rear axle is equipped with an additional adjustable drive unit comprising a second friction clutch, which is used to control the torque applied to the rear axle.