What was found
MAIN DOOR MOTOR: WHEN RAISING THE MAIN CABIN DOOR USING THE AIR STAIR DOOR SWITCH FROM INSIDE THE CABIN. THE DOOR RAISES NORMALLY. BUT AFTER LOWERING THE LOCKING HANDLE TO THE LOCKED POSITION. THE MOTOR (THAT I ASSUME OPERATES, THE LOCKING PINS) RUNS WHAT I CONSIDER TO BE ABOUT FOUR + TIMES THE NORMAL RUNTIME. ALSO THERE IS GRINDING NOISE HEARD FROM INSIDE THE CABIN WHEN STANDING DIRECTLY IN FRONT OF THE DOOR. IN SUMMARY THE DOOR MOTOR THAT NORMALLY RUNS FROM 1 TO 2 SECONDS IT'S NOW RUNNING ABOUT 10 TO 12 SECONDS WITH A GRINDING NOISE I'VE NEVER HAVE HEARD BEFORE. CORRECTIVE ACTION: CONFIRMED DOOR LINKAGE NOISY DURING OPERATION, LUBRICATED DOOR LINKAGE IAW GL6000 AMM 12-22-00. OPS CHECKED DOOR IAW GL6000 AMM 52-11-00 OPS CHECK GOOD. NO GRINDING OR ABNORMAL NOISES NOTED AFTER DOOR WAS LUBRICATED.