Root Cause Analysis of Limited Slip Differential Noise Vibration Harshness 2023-01-1138

The primary objective of this research was to identify the root cause of limited slip differential (LSD) NVH. The study also highlighted the significance of the complete oil system influencing NVH. Impacts of Gear Marking Compound, Friction Modifier, Gear Marking Compound Level, Friction Modifier Filling Level, Reaction Plate surface finish, and Friction material were studied using Taguchi's Design of Experiment. Eaton Vertical Friction Tester (VFT), a sub-system level test stand was used to measure the performance characteristics of the clutch pack and oil. Sequential approximation method and cumulative analysis methodologies were used to analyze test data where NVH was beyond the measurement capacity of the test stand. The DOE analysis demonstrated an interaction between the Hypoid axle gear marking compound used to set the correct ring gear contact pattern during axle assembly and the friction modifier added to the axle oil.