When it's time to change the transmission and rear differential fluid, our drivetrain fluid kits make it easy. You get enough Motul transmission fluid for your gearbox, in the formula of your choice, and a bottle of fluid for the rear diff, all in one easy package
Tech note: Some people have called us asking, "How come you only include four liters of trans 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.
Choose from three options:
Option 1 is our default choice for 2007+ STI. It includes four liters of Gear 300 75W90 fluid for the transmission, and one more liter for the rear differential, as specified by Subaru. This is good for most 2007+ STI cars.
Option 2 is for owners of 2004-2006 STI cars, which have a mechanical rear diff instead of a Torsen style. Because this kit uses heavier 90-weight fluid for the rear diff, you could also run this on a 2007+ STI that's going to see higher-heat use, including track driving and/or running in very hot ambient conditions.
Option 3 is like Option 2, but for people who like the feel of the 75/90 LS fluid in the trans. The Subaru transmission does NOT require the LS additive, but some of our customers like the shifting feel with the LS fluid.
These kits are intended for the STI six-speed manual transmission. (The Legacy Spec B 6MT trans is the same.) 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.