Zodiac offers the complete line of Jims 5 Speed Big Twin transmission gears, main shafts and counter shaft. It took Jims three years to complete the project of manufacturing gears. The process included the selection of material and more importantly, to write the heat treat specifications to insure the longevity of the product. The shifting dog on the gears is all C.N.C. (Computer Numerical Control) milled. The gear tooth itself is a spun gear. They are cut on a Koepfer Gear Hub, with 7 axis C.N.C. control. All the tooling for this project was custom designed. The inspection tooling alone is another C.N.C. Koepfer. This Koepfer checks the profile, lead, pitch measuring and run out. After all this was completed, Jims proceeded with vigorous testing and more lab work. Needless to say, that this was a big job. Available are several gears for 5 Speed Big Twin from 1980 thru 2006 as well as main shafts and counter shafts for the same models.