As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING A SERVICE BULLITIN TO REPLACE THE FUEL PUMP SPLINE ADAPTER, WE FOUND THE ENGINE DRIVEN FUEL PUMP DRIVE SHAFT TO BE MIGRATING OUT OF THE FUEL PUMP AND INTO THE ACCESSORY GEAR CASE. UPON INSPECTION OF THE GEAR CASE WE FOUND A RETAINING PLUG IN THE GEAR CASE SPLINE TO BE PUSHING INTO THE GEAR CASE ALLOWING THE FUEL PUMP DRIVE SHAFT TO MIGRATE OUT OF THE FUEL PUMP.