What was found
(CAN) CLIMBING THROUGH 23000 FT THE AILERONS BECAME STIFF AT -22C . AUTOPILOT MANUALLY DISCONNECTED . AILERON TRIM MOVED BUT YOKE DID NOT. CONTROL RETURNED AT 20000 FT AND +4C . AIRCRAFT LANDED WITHOUT INCIDENT. LT & RT TENSION REGULATORS INSPECTED FOR MOISTURE, NO MOISTURE FOUND. LT & RT AFT AILERON QUADS AND AUTOPILOT INSPECTED FOR MOISTURE , NO MOISTURE FOUND BUT THE AREA WAS DIRTY. LT & RT AFT QUADS AND OUTPUT ENDS OF THE PCU'S WHERE CLEANED WITH ALCOHOL AND DRIED WITH NITROGEN. NO PARTS WHERE REPLACED.AIRCRAFT RETURNED TO SERVICE.