Abstract: A hydraulic motor unit including a hydraulic motor (1?) which is connected to two working lines (3,4). The swiveling angle (?) of the hydraulic motor (1?) is adjustable by an adjusting unit (7) which is provided with a regulating piston (8) having two piston surfaces (9, 10). The regulation pressure acting on a first piston surface (10) in a regulation pressure chamber (12) can be adjusted by a control valve (13). The control valve (13) adjusting the regulation pressure is movable between two final positions. The pressure of a working line (3, 4) is applied to a first measuring surface (23) of the control valve (13) adjusting the regulation pressure while a second, opposite measuring surface (25) of the control valve (13) is impinged upon by a control pressure piston (34) at a force that depends on the control pressure only once a threshold value of a pipe (28, 18?) supplying control pressure has been exceeded.