Companion Flange

Be sure that flat machined surfaces and the bearing cup sockets of the flange have not been damaged in removing driveshaft or in removing flange from axle. The edge of the flange that contacts the oil slinger or pinion front bearing must be smooth. Roughness aggravates backlash noises and causes wear on the slinger with a resultant loss in drive pinion bearing preload. The seal surface should be perfectly smooth or leakage will result.