The test beds for gear transmissions tests, enable the simulation of real contact conditions, generated on the gear teeth mesh and its behaviour evaluation, under established conditions, reliably fixed and monitored, such as: speed, torque, lubricant temperature, and others. These tests are used for lubrication analysis, wear and major destructive phenomena with negative influence on the gears life. This paper present the design of two test rigs for spur gears assessment, focusing the Contact Fatigue Strength and bending tests, which are the two main design criteria applying to the gears transmissions. These machines allow the behavior evaluation about such phenomena of different materials types, lubricants, additives, geometry modification, and other issues affecting the gears performance. It also establishes a test procedure, and just provides all planes for the machine manufacture and test specimens.