What was found
CREW REPORTS MODERATE VIBRATION FELT FROM TAKEOFF TO CLIMB AND DIMINISHING SLIGHTLY WHEN REACHING CRUISE. WHILE TROUBLESHOOTING AT CRUISE, INPUTS OF RUDDER OR AILERON HAD NO EFFECT. VIBRATION FELT IN FLOOR, COLUMN AND THROTTLES. ALSO THERE WAS A AUDIBLE N1 OUT OF SYNC BEAT FELT. ACCOMPLISHED INLET AND EXHAUST INSPECTION ALL NORMAL. EXTENSIVE WALK AROUND ACCOMPLISHED. NOTHING NOTED WITH REGARDS TO DOORS OR PANELS.