The Whiteline Flat Out differential mount inserts or "positive power" kits for the 08-10 Subaru WRX/STI are easy to install solution to get rid of the "clunk". Have you ever experienced that terrible clunking sound during shifts? That is your differentials moving around! The Whiteline differential mount insert or mount kits will get ride of that annoying sound and get more power to the ground. The diff mounts in factory form allow the diffs to move around a lot. The clunk is most noticeable during acceleration from a stand still and shifting gears quickly. The Whiteline positive power kits will provide the driver with a precise gear shift and predictable clutch engagement.

The rear insert kit installs very quickly and easily with simple hand tools. The front and rear mount kits replace the differential mounts with a more rigid design featuring Whitelines signature polyurethane to increase ridigity greatly and prevent slop. Whiteline includes all necessary hardware for installation as well as a grease packet and instructions.