I just replaced my Quiet Quad a few weeks ago because it was getting loud and cycling all the time...wow what a difference! It almost sounds like something has failed inside your pump itself and has become out of balance causing all the vibration. I've watched mine operate and it hardly moves at all. The only thing I can suggest is to check the rubber foot mounts which are detachable and can pop out, and also check the wiring to the pump to make sure it's heavy enough gauge wire to support the pump since Four Winns likes to undersize it's wiring to it'd loaded devices
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