As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NOTED TRIM WHEEL COULD BE TURNED WITHOUT CHAIN OR SPROCKET MOVEMENT APPROXIMATELY 2 CLICKS OF TENSIONER. DISASSEMBLED WHEEL, SHAFT, AND SPROCKET AND FOUND ROLL PIN SECURING SPROCKET TO SHAFT IN 3 PIECES. SAFETY WIRE WAS HOLDING TOGETHER ENOUGH THAT TRIM STILL WORKED. SUBMITTER SUGGESTED CLOSE ATTENTION NEEDS TO BE USED TO DETECT PROBLEM.