Twin Power's Oil Pump Check Ball for 1937-1999 Big Twin models (excluding 1999 Twin Cam) is a precision steel component that works with the pump check system to help maintain proper oil pressure, prevent drain back when the engine is off, and provide a reliable replacement option for worn or pitted original parts in stock or rebuilt motors.

• Helps maintain proper oil pressure and prevents oil drain back
• Fits 1937-1999 Big Twin models (except 1999 Twin Cam)
• Includes (10) oil pump check valve balls.
• Direct replacement for OEM H-D 8866