As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ANNUAL INSPECTION FOUND NUT CRACKED. NOTHING UNUSUAL NOTICED AS FAR AS INSTALLATION WAS CONCERNED. FOUND THAT NUT CRACKED IN THE CENTER OF THE V ON THE SMALLEST DIAMETER PART OF THE NUT. INSTALLED NEW NUT AND TORQUED TO SPECS. OTHER ENGINE CHECKED AND FOUND TO HAVE A DIFFERENT STYLE NUT.