To operate a safe shutdown of the unit on a slope or in an emergency to ensure an immediate halt regardless of the hydraulic system, the installation of a spring-loaded disc brake is appropriate. In front and bevel gear, similar to the Figure, the brake can be provided on the second shaft. When a tracked vehicle transmission according to the Figure, a disc brake a hydraulic motor between the b and c helical planetary gear is installed. The brake engages to drive the vehicle at rest. When driving, the brake is hydraulically released from the working circuit.