In a steering drive axle, particularly for agricultural tractors, the transverse transmission members (16-20) which bring the drive from a central differential (12) to the wheel hubs (13a) comprise a half-shaft portion (18) having a first end connected to a universal joint (17) at the output from the differential (12), and a second end connected to a constant-velocity joint (19) fixed for rotation with a respective hub (13a). The half-shaft portion (18) is mounted for rotating on a support means (22) connected (23) to articulated suspension means (14, 15) in a manner such as to support the outer end of the half-shaft portion (18) and the inner end of the constant-velocity joint (19).