Abstract: An arrangement for driving a trackbound traction unit and being self-adjusting in both the forward and rearward directions. The arrangement includes at least two drive wheels with associated transmissions, two carrier arms whose longitudinal axes substantially parallel with the longitudinal direction of the traction unit and on one end of which the drive wheels are journalled, a holder in which the other end of the carrier arms is pivotally journalled by means of spherical bearings, a hydraulic piston-cylinder device which is connected to the first-mentioned ends of the carrier arms, and a rail which is fixedly mounted to the chassis in the center of the track. The carrier arms are substantially perpendicular to the geometric axes of the drive wheels and are intended to swing the drive wheels into pressured abutment with the center rail through the medium of the hydraulic piston-cylinder device.