What was found
(CAN) FLIGHT CREW REPORTED THAT THE AILERON SYSTEM HAD BECOME PROGRESSIVELY STIFFER DURING THEIR FLIGHT. MAINTENANCE INSPECTED THE AIRCRAFT, CLEANED AND LUBRICATED PULLEYS AND BEARINGS IAW THE MM THE AIRCRAFT WAS RELEASE FOR A FERRY FLT. MAINTENANCE FOUND BEARING BINDING IN THE CAPTAINS CONTROL COLUMN. COLUMN REMOVED AND DISASSEMBLED, REMOVED AND REPLACED BEARINGS, SYSTEM REINSTALLED AND CHECKED SERVICEABLE. AIRCRAFT RETURNED TO SERVICE.