The Spiral Bevel gear used in differential should be enough stiff to resist the vibrations and stresses encountered during its operation. The gear must also have sufficient strength to bear the bending stresses occurring in the differential assembly in its course of operation. This research is typically focused in designing a differential gear with least weight and minimal stresses. The model of the gear is designed in the Solidworks version 2015 while its analysis is carried in ANSYS 14.5. The number of parameters and levels involved in designing are more; the number of probable models is too many. To choose the optimal parameter among the list of choices, TAGUCHI method along with Finite Element Analysis (FEA) is used. By application of TAGUCHI method, not only the time required to design all the probable models is reduced, but also the time required to analyze all the models is cut down. Orthogonal Array has been incorporated to change the parameters necessary for reducing the weight of the gear. To get the best possible model of gear, FEA is then performed on the designed models. This process not only saves production time, but also prevents material wastage and production cost.