What was found
DURING ROUTINE INSPECTION, MECHANIC NOTICED THERE WAS ABNORMAL AMOUNT OF WEAR ON THE STARTER RING GEAR FOR ONLY HAVING 43 HOURS TT ON THE PART. UPON FURTHER INSPECTION, FOUND THE WRONG P/N RING GEAR INSTALLED. THE CORRECT RING GEAR IS P/N 72566 WHICH IS FOR A RT ROTATING ENGINE. THE P/N LW-10551 RING GEAR IS FOR A LT ROTATING ENGINE. THIS IS EVIDENCED WHILE SITTING IN THE PILOT SEAT, THE RING GEAR BEVEL (CHAMFER SIDE) SHOULD BE ON THE RIGHT SIDE FOR RT ROTATION, AND LEFT SIDE FOR LT ROTATION. ALTHOUGH THERE WERE WEAR MARKS, SYSTEM OPERATIONS WERE NORMAL.