Investigation of Frequent Pinion Seal and Hub Seal Leakages on Heavy Commercial Vehicles

The automotive sector is going through a phase of stiff competition among various Original Equipment Manufacturers for increasing their profitability while ensuring highest levels of customer satisfaction. The biggest challenge for such companies lies in minimizing their overall cost involving investments in Research and Development, manufacturing, after sales service and warranty costs. Higher warranty costs not only affect the net profit but in turn it also affects the brand image of the company to a large extent in the long run. An effort is made here to target such warranty costs due to frequent tail pinion and hub seal leakages on single reduction/hub reduction axles of Heavy Commercial Vehicles in the field. A preliminary study involving the severity analysis of such failures is followed by a step by step investigation of these failures. Investigation basically focuses on the temperature and internal pressure mapping of the differential in different modes to correlate the seal characteristics with the usage profile. Tests are carried out on two vehicle models having different transmission differential configurations (6×4 and 4×2 respectively). Discussion includes vehicle level test setup and procedure followed to simulate the actual failure pattern during the highway trials in the real user environment. Another set of tests are carried out with the necessary modifications in order to understand the level of improvement made. Finally, recommendations are made based on the comparative study of the results.