Sealing plug for a reducer casing, bearing a meshing play-compensating carriage

A plug intended to close an orifice of a casing, said plug comprising

• a hub, with a central axis and without any through-holes, arranged so as to plug the orifice of the casing,
• a retaining member secured to the hub and arranged so as to cooperate with the casing in order to ensure axial fastening of the plug in the orifice of the casing,
• a lash adjustment carriage, which is distinct from the hub and which is movably mounted on a guide support carried by the hub, said guide support being arranged so as to axially retain said lash adjustment carriage and to guide relative displacement of said lash adjustment carriage relative to the hub according to a lash adjustment direction transverse to the central axis,
• a spring-type elastic member interposed between the guide support and the lash adjustment carriage so as to elastically urge said lash adjustment carriage in displacement according to the lash adjustment direction,
• an orientation member configured to cooperate with a matching orientation member in the casing to orient the plug and consequently orient the lash adjustment direction in a predetermined orientation with respect to the casing and a predetermined azimuthal orientation about the central axis.