This manual is a step by step guide of how to rebuild the IRS transaxles used in 70's beetles. The manual can also be used to rebuild swingaxles, if something else is used to reference the diff. The early swing axles (Pre 66) will benefit from the later variations of the parts used in the IRS transaxles. The gear stack build up is also exactly the same for the bus 3 rib and 5 rib transaxles.