Abstract: A double helical gear set having a pair of driving pinions meshed with a pair of driven gears, respectively, is aligned by providing accurately aligned integral or demountable pinions on one shaft and aligning the driven gears using a fixture which is operable to locate a keyway or other aligning device on each of the driven gears so that the driven gears can be timed or aligned on their support shaft. The fixture has a hub member which fits in the bore of the gear hub and includes a locating pin engageable with opposed flanks of adjacent teeth at corresponding points on the tooth profile such as the pitch point. The fixture includes interchangeable locating pin support members for use in aligning helical gears having different diametral pitches and helix angles.