Effect of Lubricants on Rear Axle Pinion Bearing Break-In

Abstract

The effect of lubricants on rear axle pinion bearing break-in has been studied in a motored differential carrier assembly. The pinion torques and lubricant temperatures measured with a multipurpose lubricant were higher than those observed with a lead soap-active sulfur lubricant whereas the bearing wear was lower. Preheat treatment of the multipurpose lubricant was effective in producing more rapid pinion bearing break-in and lower lubricant temperatures. A zinc dialkyldithiophosphate was found to exert a predominant effect on break-in as compared to sulfurized terpenes and chlorinated paraffins when these additives were blended with a straight mineral oil. It has been concluded that a zinc organodithiophosphate may control pinion bearing break-in with the multipurpose lubricant.