What was found
FLIGHT CREW REPORTED EXCESSIVE VIBRATION FROM L/H ENGINE AREA FOLLOWING LANDING AT PWK. NOTED EXCESSIVE DUST AND DIRT, ETC. ON AND AROUND L/H ENGINE STARTER/GENERATOR. REPLACED STARTER/GENERATOR WITH AN EXCHANGE STARTER/GENERATOR, ENGINE VIBRATION NORMAL. DURING TEAR-DOWN OF REMOVED STARTER/GENERATOR FOR OVERHAUL, NOTED ANTI-DRIVE END BEARING BURNED, EVIDENCE OF BEARING SPINNING IN END BRUSH SUPPORT ASSY. END BELL HOUSING. INSTALLED BEARINGS APPEAR NON-STANDARD; MARKINGS SHOW MANUFACTURED IN CHINA BY PEER, P/N W6204RLD, WITH ADDITIONAL MARKING OF "ZA12". DRIVE END BEARING SIMILAR, EXCEPT WITH "ZA13" MARKING. TRANSIENT ACFT, MX HISTORY UNKNOWN.