37072-79 Transmission Filler Plug for 4 Speed Big Twin

This transmission filler plug is a high-quality reproduction of the original equipment part, manufactured by Colony to ensure a perfect fit on your vintage 4-speed gearbox. It is designed specifically for 4-speed Big Twin models, including FX and early Softail applications. Replacing OEM 37072-79, this plug is an essential component for keeping your transmission fluid contained and protecting the internals from road grime and moisture. Whether you are finishing a ground-up restoration or just replacing a damaged or missing plug, this part offers the correct look and function for your classic Harley. It is built with the durability needed to withstand years of service on the road.