As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON ENGINE BUILD-UP TO INSTALL THE PROP DEICE BRUSH BLOCK BRACKET ASSEMBLY. ONE OF THE BOLTS THAT GO THROUGH THE CASE HAD TO BE REMOVED. THE THREADS OF THE BOLT WERE MARKED UP. ON FURTHER INVESTIGATION IT WAS FOUND THAT THE BOLT HAD BOTTOMED OUT IN THE HELICOIL INSERT. TOO LONG OF A BOLT WAS USED. NEW HELICOIL WAS INSTALLED AND PROPER BOLT LENGTH WAS USED.