Scion XD/XA/Yaris compatibility

[CrankyOldMan]

Apologies, I lost track of the original question. The only guaranteed way I know of to get a different final drive without fitment issues is to change the pinion shaft and ring gear. That requires a full tear down of the gearbox and disassembly of the pinion shaft, or a donor gearbox to swap the internals from. The external mounting points and shift linkage are probably different, so a 1:1 swap probably won't work. Take a look at my transmission teardown gearbox comparison thread for details. If you're reasonably handy with tools and can follow the repair manual, it's not a terribly difficult job. There's a few specialty tools that will make it easier, but the gearbox can be torn down and put back together in a weekend, easily.

I would stay away from the xD gearbox unless you're prepared to mess with drive shaft fitment issues, since you'd be changing out the inboard stubs to get the xD splines, and the length is probably different. There's a recent thread where someone made the swap and it was a big headache trying to find axles that connected the xD gearbox to the Yaris hubs.

Gearbox comparison thread: http://www.yarisworld.com/forums/showthread.php?t=38477