What was found
DURING DESCENT, FL300 BELOW LT OTBD ELEVATOR FLUCTATED UP & DOWN ON CONFIGURATION PAGE. AT 3000 FT ON APPROACH- FELT CYCLING IN YOKE TO A BUFFETING- AUTOPILOT OFF- WENT AROUND-AUTOPILOT SEEMS TO HELP. IAW CREW DEBRIEF, THEY NOTICED ISSUE DURING PREFLIGHT CHECK PRIOR TO DEPARTURE SEEMED TO GO AWAY CONTINUED ON. AFTER BLOCK IN RAN HYD AND CYCLED ELEVATORS SEVERAL TIMES NOTICED A RATCHETING IN CONTROL COLUMN AND AN AUDIBLE HISSING SOUND FROM GROUND, APPEARS TO BE FROM LT INBD ELEVATOR ACTUATOR AREA, WHEN HYD ON AND NO MOVEMENT. RT SIDE NORMAL. TRIED TO LOCATE HISSING SOUND TRACED IT TO AFT ACCESSORY COMPT. RAN HYD, CYCLED ELEVATOR THROUGH MULTIPLE TIMES WITH STAB SETTING AROUND 1.3. THE HISS IS MORE PRONOUNCED AND THE RACHETING THROUGH THE CONTROLS FROM ALL THE FWD BACK THROUGH NEUTRAL. THE VIBRATION SHAKES THE WHOLE ACFT AND IS VISABLE THROUGH THE ELEV LINKAGE. WHEN STAB SETTING IS GREATER THAN 2 SMOOTH MOVEMENT AND SOUND SUBSIDES. NO FLUID LEAKAGE NOTED IN THIS COMPT OR FROM ANY ELEVATOR ACTUATORS. THE VIBRATION IS MOST NOTICABLE AT CURRENT STAB SETTING 1.3. REMOVED AND REPLACED RT OB ELEVATOR ACTUATOR THROUGH STEP 29 AND COMPLETED RIGGING.