What was found
AIRCRAFT WAS GROUNDED. AIRFRAME VIBRATION IN CLIMB 240KTS TO 310KTS FL 190 TO 310, ENGINE VIBRATION LEFT HAND N1-.4, RIGHT HAND N11.4-1.8 N2, LEFT HAND .5, RIGHT HAND .1. AFT LEFT HAND NOSE GEAR DOOR HAS LOOSE ATTACH FITTINGS BOTH FORWARD AND AFT. MAINTENANCE FOUND LOOSE ATTACH FITTINGS ON AFT NOSE LANDING GEAR DOOR, REPLACED ATTACH FITTINGS, INSTALLED AND ADJUSTED DOOR PER AMM 32-22-13-400-001A.