Automobilaren ardatz erdiari ere deitzen zaioardatz motorra, which connects the differential with the drive wheels. The ardatz motorra is the shaft that transmits torque between the gearbox reducer and the drive wheels. There is a universal joint (U/JOINT) at the inner and outer ends of the shaft, which is connected to the reducer gear and the inner ring of the hub bearing through the spline on the universal joint.
Theardatz motorrapotentzia diferentzialetik ezkerreko eta eskuineko gurpil motorretara transmititzen du.