As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOLT ON THE SPLINE ADAPTER TO THOMAS COUPLING CAME LOOSE CAUSING T/R SHAFT DAMAGE. SUSPECT CAUSE WAS LOW TORQUE TO NUT. TARE TORQUE ON NUT WAS CHECKED TO BE 5 INCH/POUND AT RE-ASSEMBLY. SUBMITTER SUGGESTED USE OF NEW HARDWARE EACH TIME SHAFT COMPONENTS ARE DISASSEMLBED FOR MAINTENANCE.