Root Cause Analysis of Limited Slip Differential Noise Vibration Harshness

The primary objective of this research was to identify the root cause of limited slip differential (LSD) NVH. The study examined the significance of different oils and additives that make up the lubrication mix in the axle. The impacts of gear marking compound type, friction modifier type, gear marking compound level, friction modifier level, reaction plate surface finish roughness, and friction material type were studied using Taguchi's Design of Experiment. Eaton's Vertical Friction Tester (VFT), a sub-system level test stand, was used to measure the performance characteristics of the clutch pack and oil mix. Sequential approximation and cumulative analysis methodologies were used to analyze test data where NVH was beyond the measurement capacity of the test stand. The DOE analysis showed that the type of gear marking compound used to set the ring gear mesh during axle build had the most significant influence on NVH levels.