The shaft seals on a stock throttle body can only withstand a limited amount of pressure before they fail, especially as they get older.

The shaft seals on a stock throttle body can only withstand a limited amount of pressure before they fail, especially as they get older. Even other aftermarket seals are only rated for 7 psi and are usually ill-fitting. If you plan on tuning your EVO and running higher boost, these seals can give way leading to more expensive problems and troubleshooting frustrations. Some enthusiasts have experienced more than a 2 psi pressure loss! Thankfully WORKS has addressed this issue by developing special high pressure shaft seals for our Aperture throttle bodies. Designed to fit like the stock throttle shaft seals these stronger units are rated to 25+ psi (well above the factory/aftermarket 7psi mark) thanks, in part, to the properly sized, OEM-style metal casing surrounding the specially designed WORKS internal rubber seal. These are a must if you plan on running a big turbo or cranking up the boost on a stock turbo. Reasonably priced, the WORKS High Pressure Aperture Shaft Seals are an affordable way to prevent engine problems on tuned EVOs.

This complete kit also includes a new OEM throttle body gasket and WORKS Installation Instructions.