Artigo Completo:

The truck and busses rear axle production process characteristics does not remove all impurities in parts per million (PPM) of metallic and non metallic materials, than as necessary a premature oil change knower “first replacement oil”. This kind of service occurs at five thousand kilometers in average to assure the internal components life (gear assy, retainers and bearings). Evaluating the material properties and rear axle functionalities characteristics were defined to fixing some magnets inside the rear axle housing separated according to minimum distance specification each other. The main idea is attract the metallic particles in oil at rear axle to the magnets (ferromagnetic properties) and also non metallic particles by mechanical friction created by oil movement around gear assy. Considering the impurities volume found out at samples universe at durability tests done are in PPM, the magnets dimension were defined to all rear axle life prediction. Oil samples were evaluated during durability test according to truck and busses maker, rear axle supplier and oil laboratory specialist definition. Up to now, the results show the materials reduction at suspension particles at oil and physical chemical characterizes oil stability after one hundred twenty five thousand kilometers (125.000 km). Were considered, based on the results, the magnets assembled at rear axle housing avoid the first replacement oil. Evaluating all analysis results were defined to increase one hundred kilometers (100.000) and keep the oil analysis. Tear down will be done, according to test schedule, after two hundred twenty five thousand kilometers (225.000 km) to evaluate the gear assy regarding a wear and carbon case reduction, retainers condition, bearings and lubricant oil condition to confirm all rear axle components and lubricant oil life prediction and also analyze the new rear axle oil change interval possibility.