If the bearings and fan aren't rusted in place a bearing replacement should be easy. May have to buy a small bearing puller at Sears, Home Depot, Lowes, auto stores etc. Really have no idea why they don't last for you. Been running my Hayward Superpump since 97 and no problems. Then again it's in a poolhouse out of the weather but that shouldn;t affect the bearings which should be sealed.
Al