What was found
CONSTANT VIBRATION FELT IN AFT GALLEY FLOOR. CREW ELECTED TO RETURN TO MIA. *S/D* THE BOOT, (P/N S212W301-9, IPC 36-12-04-005, ITEM 155) AT THE PENETRATION OF THE APU DUCT INTO THE AFT DOME OF FUSELAGE, WAS FOUND TORN IN THE SEAM. FURTHER EXAMINATION OF THE BOOT REVEALED THAT THE STEEL RING (INSIDE THE BOOT) SNAPPED AT THE WELD. THE BOOT WAS REPLACED AND THE AIRCRAFT RETURNED TO SERVICE.