Lubrication level diagnostics using vibration analysis

The purpose of this paper is to show how vibration analysis can be used to detect lubrication loss in an automotive type drive train differential. This preliminary test consisted of gathering broadband vibration data on two differentials on a U.S. Marine Corps light armored vehicle (LAV). One differential was used as a control, where the lubrication level remained full throughout testing and the other was the test differential where the lubrication levels were varied from a full to half full to completely empty. The results of the data analysis indicate that lubrication loss can be detected using vibration analysis when using a frequency band between 15 kHz and 24 kHz. This result shows that an accelerometer can be used not only for detecting faults in mechanical components including gears, bearings and shafts but can also be used to detect lubrication loss for the same system with unique processing. Future research can evaluate the effects of vehicle speed and load on the processing and analysis results and the effect of lubrication loss on the performance of algorithms for bearing and gear fault detection.