Polymer gears are extensively used in motion and power transmission systems at varying speed and loading conditions in variety of automation applications. Performances of these polymer gears are severely influenced by operating torque conditions. Polymers can be made into complex shapes using injection moulding process with increased production rates and low-cost fabrication of parts. Performances of injection moulded glass fiber reinforced plastic gears are investigated in this paper. Injection moulded unreinforced commercially available delrin and 20% glass fiber reinforced polymer gears tested at different speed and loading conditions are presented. Performances monitoring of these gears were done using a dedicated gear test rig. Unceasing measurement of wear on the polymer gears were carried out for all testing conditions. Online surface temperature of gear tooth was recorded and deformation of gear tooth due to applied torque was observed to acquire clear knowledge of performances of test gears. The increase in wear rate and surface temperature for unreinforced delrin and glass fiber reinforced delrin were found to be linear since the critical torque was not used in testing conditions.At all the testing conditions, performances of glass fiber reinforced delrin gears were observed to be comparatively higher than unreinforced delrin gears due to high stiffness and resistant to thermal deformation offered by glass fiber reinforcement. © Research India Publications.