The measurement of Gear Transmission Error as an NVH indicator: Theoretical discussion and industrial application via low-cost digital encoders to an all-electric vehicle gearbox

•TE is accurately measured by the Elapsed Time Method (ETM) and low-cost digital encoders.•This method substantially improves maximum speed and ease of instrumentation.•A validation with the traditional Direct Method is provided through a precision gear test rig.•The ETM is applied to the industrial case of a full-electric car gearbox.•Robustness of the method is proven and TE is found to be a useful NVH indicator.