What was found
DURING AN INSPECTION ON A CESSNA CARAVAN 208B5228 THE AILERON AND ELEVATOR TRIM ACTUATOR LUBRICATION WAS DUE. THE ACTUATORS WERE DISASSEMBLED AND INSPECTED. FOUR EXTERNAL THREAD SCREWS IPC 27-30-02 FIGURE 4 ITEM 3 WERE MEASURED TO BE UNDER ALLOWABLE DIMENSION. RECEIVED 4 SCREWS FROM TEXTRN. ALL FOUR SCREWS WERE FOUND TO BE UNACCEPTABLE DUE TO THE CREWS NOT THREADING SMOOTHLY INTO THE INTERNAL THREAD SLEEVES. ALL FOUR SCREWS WERE TESTED WITH OLD AND NEW INTERNAL THREAD SLEEVES AND FOUND UNACCEPTABLE. SOME OF THE SCREWS WOULD NOT EVEN THREAD INTO THE INTERNAL THREAD SLEEVE. MCFARLANE SELLS A PMA REPLACEMENT FOR THESE PARTS. FOUR OF THE THE MCFARLANE SCREWS WERE ORDERED AND RECEIVED. ALL FOUR OF THESE SCREWS ACTUALLY HAD THE SAME PROBLEM. IF WE PUT ANY OF THESE PARTS IN SERVICE THE ELEVATOR TRIM WOULD HAVE BEEN EXTREMELY STIFF OR POSSIBLE JAMMED IN FLIGHT.