When it's time to change the transmission and rear differential fluid, our kits make it easy. You get enough Subaru Extra-S transmission fluid (4 one-quart bottles) for your gearbox, and a two-liter bottle of Motul 90PA fluid for the rear differential.
Tech note: Some people have called us asking, "How come you only include four quarts of gearbox fluid when my service manual says more?" The answer is that when you're changing the fluid, a lot of the fluid is going to stay in the transmission, stuck between the gears and other parts. The result is that it takes less fluid than the manual specifies to fill the transmission full. The amount we sell in these kits is just the right amount for your fluid change.
This kit is intended for the STI six-speed manual transmission. The 2015+ WRX six-speed is based on the older five-speed transmission, so it uses this kit.
The BRZ/FR-S six-speed manual is again a different gearbox. We do have a kit for that car, too.