What was found
AT FL410 WITH AUTOPILOT ENGAGED, ACFT BEGAN 10 DEG LT & RT ROLL OSCILLATION WITH A 1 SEC TIME AMPLITUDE. OSCILLATIONS CONTINUED 18 MINS. OPS NORMAL WITH AP DISENGAGED. DESCENDED TO FL360. RE-ENGAGED AP & 5 MINS LATER AUTO PILOT ENGAGED, OSCILLATIONS BEGAN AGAIN WITH CYAN CAS MESSAGE AILERON RATIO LOW. CONFIRMED LT AILERON OSCILLATING. ALL HYD PRESS & QTY NORMAL. FOUND FWD FUSELAGE AILERON CABLE TENSION HIGH. ADJUSTED Y2 TURN IN SPEC. CHECKED & FOUND LT AILERON POSITION DRIVE COUPLER CRACKED, REPLACED AILERON RESOLVER FLEX LINE. CHECKED & FOUND A+B AILERON RATIO ACTUATORS LEAKING, REPLACED BOTH ACTUATORS. INSTALLED FWD FAIRING PANELS, INSPECTED RIG & CONDITION OF AILERON RESOLVER SYS, NO DEFECTS.