I had determined from my years of experience with Mazda rotary cars that they loved to rev. A Volkswagen beetle's engine doesn't! So I needed suitable gearing for this whole project to work properly. A Type-2, or transporter transaxle was chosen for it's gearing and strength. I had much experience with transmissions on VWs, and opened up the transmission that I got from some source I know longer can recall now. You should not use the early IRS bus transmission with the bolt-on side covers. They have many internal parts that need to be upgraded. The ones with a threaded collar like the one pictured are best. I did this when their were only 4-speed transmissions available, now you have 5-speeds. I don't know if you can use a 5-speed for this swap.

The shifter linkage support bracket on these transmissions is not too strong, so I beefed it up with an overlay of metal stock. This is the part under the nose cover where the shifter rod goes into the transmission. The bracket breaks at one of the bolt holes used to secure it to the gear case. Just make sure the linkage clears the additional piece you place there. The gearing of this transaxle was something like 5:38 final drive, the beetle's was in the neighborhood of 4:12. This would make the high revving Mazda engine much happier.

More on fitting this transmission into a Beetle later.