As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT, THE CREW NOTICED THAT THE SMALL CIRCLIP (PN DIN471-08-VERZ) THAT SECURES THE MLG DOWNLOCK HOOK PIN IN POSITION WAS MISSING. MAINT JACKED THE AC AND INSTALLED A NEW CLIP. WHEN THIS CLIP IS NOT IN PLACE, THE PIN MIGRATES AFT AND IN SOME CASES DAMAGES THE AFT LIP OF THE WHEEL WELL MATERIAL. THIS OPERATOR HAS 9 OF THESE AIRPLANES AND THERE HAVE BEEN OTHER INSTANCES OF THIS DISCREPANCY.