As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VERTICAL FIN AFT SPAR TO BULKHEAD CLEARANCE EXCESSIVE. MAXIMUM CLEARANCE .070 INCH PER CESSNA 172 SM. P/N 0512159-3 INSTALLED INCORRECTLY OR MACHINED INCORRECTLY BY FACTORY AT LOWER HOLE MACHINE FACE. MISSING .090 INCH OF MATERIAL. FIXED BY INSTALLING .090 INCH 204T3 SHIM ON BULKHEAD 0512159-3 AFT FACE.