There is provided a method of forming a ring gear, including providing a tube having an inner surface comprising gear teeth, the tube being a hollow tube formed by extrusion. The method also includes inserting a shaping tool into the tube, the shaping tool having tool teeth to mate with the gear teeth, and extended and retracted configurations. The shaping tool may be inserted into the tube in its retracted configuration. Moreover, the method includes extending the shaping tool into its extended configuration to cause the tool teeth to mate with the gear teeth and to exert a radially outward force on the tube. Furthermore, the method includes fixing a shape of an outer perimeter of the tube, retracting the shaping tool into its retracted configuration to reduce the radially outward force exerted by the shaping tool on the tube, and removing the shaping tool from the tube.