Universal Joint Flange, Rear Axle

Be sure that the surfaces of the rear axle companion flange have not been damaged in removing the driveshaft or in removing the rear axle companion flange from the rear axle assembly. The end of the rear axle companion flange that contacts the front differential pinion bearing inner race or slinger washer, as well as the flat surface of the pinion nut counterbore, must be smooth. Polish these surfaces if necessary. Note also the barrel of the rear axle companion flange for any damage which could permit the pinion seal to leak. Roughness aggravates backlash noises and causes wear of the rear axle companion flange and pinion nut, with a resultant loss in pinion bearing preload.