If you’re a guy who bought a TDI for fuel efficiency and most of your driving is on the highway then a 5th ratio change can help you net some nice MPG increases. This is a fairly easy upgrade if you know what your doing and have the special tools.

This car was driving 1 hour to work and 1 hour home every day. This was a prime candidate for 5th ratio change. Here’s with the 5th cover removed. Notice the filth stuck to trans case inside in all the following pics. Probably would be best to change the fluid a little more often.

The slider on this car had some wear. Dark pic but it was the only way to see the wear in the picture. I suppose I need a camera with Micro function. This part should have been replaced but due to time constraints it wasn’t. Car worked fine before and after 5th upgrade though. It’s easily changeable later, so no big deal.


You use a puller to get off the hub and slider, and then the 5th main gear will slide off. Then you use another puller to pull off the 5th counter gear. The teeth on these can crack during pulling.


With both gears removed.