What was found
ON CLIMB-OUT ACFT UNUSUAL VIBRATION PASSING 11,000 FT & ACCELERATING THROUGH 335 KIAS. DECREASED AIRSPEED & VIBE STOPPED AT 315 KIAS. ACCELERATED AGAIN & AT FL 180, 325 KIAS VIBE RETURNED, DEPLOYED SPOILERS & VIBE SMOOTHED OUT. STOWED SPOILERS & VIBE RETURNED. CLIMBED TO FL 320 - PASSING MACH .83 VIBE RETURNED. FOUND NUT & ECCENTRIC MISSING ON SIDE PLATE ON LT INBD AILERON. BEARING IS STILL IN PLACE, UNSURE OF CONDITION. R & R LT FLAP TE SIDE PLATE ASSY. NO DAMAGE NOTED ON TRACK ASSY. AT REMOVAL, ADJUSTED LT TE FLAP IAW MM 27-51-001-5. ADJUSTED LT & RT INBD & OUTBD TE FLAPS PER MM 27-51-001-5 & 27-51-011-5. OPS CHECKED GOOD. NO OTHER DEFECTS NOTED.