As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE PIN THAT HOLDS THE DRIVE GEAR ONTO THE ACTUATOR DRUM HAD FALLEN OUT WHEN THE AIRCRAFT WAS TRIMMED NOSE UP. THE PILOT HAD TO PUSH ON THE YOKE WITH GREAT FORCE TO PITCH THE AIRCRAFT DOWN. AFTER EXAMINING THE ACTUATOR, NOTICED THAT THE HOLE FOR THE PIN WAS ELONGATED AND WOULD NOT HOLD A NEW PIN. RECOMMEND SOME SORT OF CLAMP BE INSTALLED TO INSURE THE PIN COULD NOT BACK OUT.