As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL450 WE GOT A RED E WITH A DOWN ARROW ANNUNCIATION ON BOTH PFD’S. RON WAS PF AND FIRMLY GRIPPED THE YOKE AS I GAVE HIM A 3,2,1 COUNT AND DISCONNECTED THE AUTOPILOT. THE AIRPLANE’S NOSE TRIED TO RISE AND RON WAS ABLE TO CONTROL IT WITH FORCE. WE BOTH TRIED TO MOVE THE ELEVATOR TRIM AND NEITHER OF US COULD DO SO. GAINED ACCESS TO THE ELEVATOR TRIM ACTUATORS LH/RH FOUND GREASE ON CHAINS. REMOVED GREASE ON CHAINS CLEANED AND LUBED WITH LPS AND MOLYCOTE