Torque Solution Rear Differential Lockdown SystemTorque Solution Rear Differential Lockdown Applications: Subaru Impreza, WRX STi 2008 2014 Torque Solution continues to push the limits of high performance aftermarket products with our "NEW" Rear Differential Lockdown System. This system was designed to completely stop movement of the rear Differential. This helps to improve transmission feedback when shifting, and gives the car a more solid feel under hard acceleration. Get rid of that clunk and