What was found
SHIP 8308 -ATB- DUE TO RECEIVING AN ENG VIBE MESSAGE AND A MASTER CAUTION LIGHT SEVERAL TIMES AFTER TAKEOFF. PER QRH EFFECTED ENGINE TO BE OPERATED AT REDUCED THRUST, RETURNED TO DFW. CORRECTIVE ACTION: INSPECTED THE MCD'S AND FOUND METAL ON THE #3 BEARING COMPARTMENT AND ANGLE GEARBOX MCD'S. ENGINE REPLACED. (LP# 7879994, 7879995)