0058502 Spring, seal ring oil separator

To ensure the oil separator seal ring maintains constant contact and functions properly, this specialized spring is required. It fits 1937 to 1973 45" Sidevalve models, 1937 to 1948 74" and 80" Big Twin Sidevalves, and 1952 to 1956 KH models. Manufactured by Samwel, it replaces OEM 25287-37. This spring sits inside the cam cover and provides the necessary tension for the oil separation system. Over time, these springs can lose their temper or become corroded, so replacing them during an engine rebuild is highly recommended to ensure your vintage Harley's breathing system remains efficient.