Swing Axle vs IRS Transmissions - How to tell the difference - Aircooled VW Tech Tips

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Here are some quick tips showing you how to tell the difference between a Swing Axle Transmission and an IRS (Independent Rear Suspension) Transmission or Transaxle on your Air-cooled Volkswagen Beetle or Dune Buggy.

Swing Axle transmissions ran from 1946-1968 on a stock Air-cooled VW Beetle or Bug. Early style buses also used standard beetle transaxles with reduction boxes on the hubs. Swing axles transmissions can easily be identified by the enclosed swing-axle tube with a single axle boot on the transmission end of the axle tube.

IRS (Independent Rear Suspension) transmissions were used from 1969 and on in VW Beetles and late-style Buses. IRS can be identified by the exposed axle, and use two CV joints (Constant Velocity Joints), and have a CV Boot on each end of both axles - 2 per axle, 4 total CV boots.


Swing axles are a budget-friendly way to get reliable power down if you are building a budget-friendly drag car, and many people agree the camber looks great on slammed beetles. In most other circumstances, IRS is the superior choice for on-road and off-road situations, offering more articulation while eliminating the extreme camber under load.

Thank you for reading! If you have any more questions regarding Swing Axles, IRS, or VW Bug Parts in general please email us: