This genuine Sherwood impeller is the 30000 model. It has 10 vanes and features a threaded/splined keyway, meaning it can be removed with an impeller puller. The neoprene impeller is designed to fit on a 15/16″ pump shaft and should only be used to pump water.
The Sherwood 30000 impeller is suitable for Sherwood G3001-01, G3001-02 and G3001X engine cooling pumps.
Sherwood marine raw water pumps all feature a flexible neoprene impeller which attaches to the shaft. The shaft rotation powers the impeller which transfers the water by creating a vacuum on the inlet side and then forcing water out in a uniform flow on the outlet side. As such an important component, you should ensure that your pump impeller is always in top condition and that you always use the correct impeller for your application. This will help to ensure the best engine performance and prolong engine life.
Sherwood recommend that all impellers are replaced at least annually (depending on application) to maintain impeller performance, however it is good practice to inspect them often to check for excessive abrasions or damage. It is also recommended that during long periods of being unused, impellers should be removed from the pump housing to prevent ultraviolet deterioration, vanes setting into position and copper bonding of the impeller to the housing. Any issues with your impeller can lead to engine overheating, which is the main reason for premature engine wear.