Ok, so I've spent the afternoon on the Galaxy and have ruled out the following: alternator pulley drive belt drive belt tensioner top swivels drop links With the engine running and the undertray removed, if the the steering is put under load the noise seems to be coming from the PAS pump. There is a very harsh vibration coming from it that I can feel in the in the steel pipe leading to the steering rack. Is there anything inside the pump like a pressure relief valve or bypass that could make this noise? Is the pump rebuildable or should I just swap it out for a new one and hope for the best?