What was found
THE PILOT NOTICED AN ENGINE VIBRATION ON DECENT INTO READING REGIONAL AIRPORT. THE #1 STARTER- GENERATOR PART NUMBER A 23085-025, SERIAL NUMBER Y0090 WAS FOUND TO BE THE CAUSE OF THE VIBRATION. THIS STARTER-GENERATOR WAS PREVIOUSLY OVERHAULED AND HAD BEEN IN SERVICE FOR 679.1 HOURS AND 801 LANDINGS BEFORE REMOVAL. THE STARTER-GENERATOR AND ENGINE WERE INSPECTED, AND AN OVERHAULED STARTER-GENERATOR UNIT WAS INSTALLED. THE AIRCRAFT WAS RETURNED TO SERVICE WITHOUT FURTHER INCIDENT. UPON CLOSER EXAMINATION THE REAR BEARING WAS THE CAUSE OF THE VIBRATION, THE VENDOR WAS CONTACTED AND A MORE COMPREHENSIVE EVALUATION WILL FOLLOW.