What was found
(CAN) ENROUTE, THE FLIGHT CREW EXPERIENCED A ELEVATOR TRIM JAM. SPEED WAS REDUCED AND DECISION TAKEN TO DIVERT TO A CLOSER AIRPORT. DURING DESCENT, THE FLIGHT CREW REGAINED CONTROL OF THE TRIM. THE ACFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE DETERMINED THAT IT HAS LIKELY BEEN THE RESULT OF A FROZEN TRIM ACTUATOR. DURING COMPLETION OF LUBRICATION TASK 2730/04, THE ENGINEER NOTICED PRESENCE OF TRAPPED AIR BUBBLES INSIDE THE UNIT. BOTH ACTUATORS WERE LUBRICATED AND THE ACFT RELEASED FOR SERVICE. ELEVATOR TRIM ACTUATORS ARE LUBRICATED IAW TASK 2730/04 AT EVERY 5000 FH INTERVALS. AN INTERNAL COMPANY TASK CALLS FOR LUBRICATION AT EVERY 2000 FH. ACTUATORS HAVE ACCUMULATED 1417 FH SINCE. LEFT ACTUATOR, PN 82760174-005, RT ACTUATOR, PN 82760174-006.