This book addresses the study on the improvement of lubricity properties of commercially available SN500 Grade gear lubricant which enhances anti-wear property due to the homogeneous dispersion of garnet nanoparticles in different concentrations. In this study, gearbox is modeled as a tribosystem where SN500 Grade gear lubricant is used as an interfacing element to separate relatively moving/sliding interacting surfaces in relative motion through the formation of lubricant film. The vital chemico-physical properties such as density, kinematic viscosity and relative viscosity of SN500 Grade gear lubricant with and without homogeneously dispersing different weight percentage of garnet nanoparticles are experimentally investigated. Also the lubricating performance is estimated by mechanico-dynamical test. The results indicates that the chemico-physical and lubricating properties of nano garnet SN500 Grade gear lubricant enhances with respect to the percentage of dispersion of nano garnet particles into the SN500 Grade gear lubricant at constant environmental condition.