<p>Gearset-drive unit ( 10 ), in particular for use in motor vehicles, comprising a drive wheel ( 16 ) that meshes with a driven wheel ( 22 ), wherein a sensor wheel ( 26 ) with a position sensor ( 36 ) that interacts with a sensor ( 42 ) to detect speed meshes with the drive wheel ( 16 ) or the driven wheel ( 22 ).</p>