What was found
AIRFRAME VIBRATION STARTED CLIMBING OUT AT FL22.5 2CD A330 KIAS. ENGINE DATA N1-104.1 2C104.23A EGT 832 2C 841 3A VIBES 0.62C+0.2 3A N2 VIBES 2.0 2C0.4. VIBRATION REMAINED THROUGHOUT FLIGHT UNTIL DESCENDING PAST FT.VIBRATION WOULD DECREASE AS POWER WAS REMOVED BUT CAME BACK AS POWER WAS REAPPLIED. ACFT SLOWED FIRST TO .78 MACH 2C THEN TO 275 KIAS NO HELP. ALL FLIGHT CONTROLS APPEARED OK EXCEPT STAB APPEARED TO VIBRATE VERY SLIGHTLY UP AND DOWN CHANGING AUTOPILOTS DID NOT HELP.