Starter was clicking but not starting; replaced with a rebuilt starter and it started and ran for a few days and then it started whining; replaced again with a new starter because we were told the solenoid was bad. NOW it's whining again; solenoid has power. All connections were cleaned. Where do I go next???

 

Disconnect the battery, pull the starter and have someone turn the engine over using the nut on the crank shaft and look for missing teeth on the fly wheel.