A pinion gear box is a mechanism that modifies the speed or direction of a spinning shaft. Each set of gears in a typical arrangement of gears produces a different speed or direction when they mesh together. Transmission systems, conveyor belts, and power steering systems are just a few of the uses for this type of tool. It is the smallest of two meshing gears in an arrangement. Depending on the application, the pinion gear box can be either the driving or the driven gear and be either of the spur or helical type. Ring and pinion and rack and pinion gearing systems are just two examples of the various gearing systems that use this tool.