ABOUT US Manufacturing CORVETTE REAR AXLES Corvette Parts looked into producing forged Corvette 1963-1982 rear axles in 1992 because of the ever increasing cost of GM stock axles and the reputation of low strength. Material strength was the major factor, stock axles were not the best for high output engines, especially when used for track. There were two driveline specialists turning out “super stock” rear kits where axles were turned from 4340 material from solid stock. Corvette Parts was one and Tom’s Differentials was the other. This type of manufacture for axles, (lathe cut from solid stock), was very costly and since it cut through the material grain lines it was not nearly as strong as a forging where grain lines follow form. Corvette Parts contacted Moser Engineering, perhaps now better known as Moser Axle. They had in their plans a Corvette axle for future production. This was to be a 4340 forging. They already had a production print but didn’t have a production date. As Corvette Parts was already in the Corvette Axle business, Moser decided to send their production print to us and we would assume production. Spencer Forge in Ohio was the choice for the forge work mainly because they produced forgings for Dana-Spicer and had a track record for forged driveline parts. Attached is a copy of the final axle print and an inspection sheet. Spencer Forge agreed to do the forging and produce the necessary tooling of (4) Four pass dies and headers and tread racks, as well as maintaining the tooling. Agreement attached. The material used in this flanged axle production was 4340 HR ASQ/SBQ material. The process was Upset Forge, Through harden, Machine complete, Induction harden and Centerless grind. Threading was form rolled - not die cut. This is the strongest type of thread. The axle used a ¾” with 20 thread which is not common and an automotive use only that goes back to the 1950’s, as was its 17 spline.