What was found
(CAN) WHILE BUILDING UP A RENTAL ENGINE FOR A SCHEDULED ENGINE CHANGE ON OUR ACFT AN INSPECTION OF THE PROPELLER SHAFT INNER BORE SHOWED SIGNS OF SCORING. THESE SCORE MARKS WERE FURTHER INSPECTED WITH A MAGNIFYING GLASS AND SHOWED SIGNS OF BEING A POSSIBLE CRACK. ACUREN WAS BROUGHT IN TO DO AN NDT INPSECTION OF THE AREA AND FOUND THERE TO BE CRACKS ON THE INNER BORE OF THE PROPELLER SHAFT. 1 CRACK IS 5.50" IN LENGTH. THE SECOND CRACK IS 1.75" IN LENGTH. THE RGB WAS R & R WITH A SERVICEABLE UNIT. THE NDT REPORT SHOWS PICTURES TO INDICATE THE AREA WHERE THE CRACKS ARE LOCATED.