As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER AUTOPILOT DISCONNECTED, CAPTAINS SIDE NOTICED BINDING OF TRIM (ELEVATOR) BETWEEN 3 AND 6 UNITS. TRIM WHEEL WOULD BIND THEN RELEASE. ALTITUDE 6000 FEET WITH NO MOISTURE. INSPECTED ENTIRE ELEVATOR TRIM SYSTEM FOR DEFECTS. NONE NOTED. ALL TESTS AND FUNCTIONAL CHECKS FOUND ELEVATOR TRIM SYSTEM OPERATING NORMAL. REPLACED ELEVATOR TRIM SERVO WITH A SERVICEABLE UNIT AS A PRECAUTION. S/N OFF 3715, ON 4545.