As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW REPORTED EXCESS BACKLASH AND PROP SYNC DOES NOT SYNC. PROP WANDERING + - 5 TO 7 RPM. ENGINE SPRING STRUT ASSEMBLY REPLACED. AFTER DISASSEMBLY IN THE O/H SHOP, SHAFT P/N 87620130-101 WAS FOUND BROKEN AT POINT RIVET P/N MS204170AD3. THE SIZE OF THE RIVET HOLE LEAVES MINIMAL MATERIAL AROUND THE SHAFT, WHICH IS PRONE TO BREAKING UNDER VIBRATION.