Decorate with adjusting nut assembly, automotive drive axle differential to support the outer edge of the differential shell bearings, bearing inner ring is nested on the differential of cylindrical shell, adjustment nut adopts screw, nut inside face contact with the bearing face, nut on the lateral face has grooves being placed locking mechanism, whose character is: described the adjusting nut assembly also includes collecting hood, adjusting nut and oil collecting cover at one end and the bottom of the oil collecting cover installation and adjusting nut end has a cavity, the cavity as temporary oil cavity, collecting hood with openings and communion with differential shell, adjusting nut and the end of the bearing contact with a number of oil inlet. The lubricating oil enters the temporary oil collecting chamber through the inlet, and then enters the differential from the temporary oil collecting chamber, so that the internal parts of the differential, such as gear and gasket, are well lubricated and the lubrication conditions of the differential are improved.