To boost/improve Yaris, or move on....?

[CrankyOldMan]

Originally Posted by Jason@SportsCar

Trans: this makes the car, you must get an LSD. If you have the money get the OS Giken, if you want to go cheaper get the TRD unit. BUT while you are in there install the xB 4.312 final drive, it really wakes the car up. You will already be paying the labor (or doing the work) to pull the stock gears when you install the LSD, it is not much more work to swap the gears.

What parts would have to be swapped out for this? I'm assuming that it's not just the drive/driven pair for 5th gear (circled in red), but a different gear that mates to the LSD or driveshafts? I'm having a hard time getting a good picture of the gearbox from these parts diagrams.



Looking at the C50 repair manual gives much better illustrations, so I'm thinking it's actually the gear that attaches to the differential? If so, then wouldn't the entire output shaft also have to be replaced?