What was found
DURING TAKEOFF CHECK, PILOT NOTICED NR 2 FUEL PRESS 12 PSI LOWER THAN NR 1. THIS IS LOWER THAN IT NORMALLY OPERATES WITH ENG AT FLY AND BOTH FUEL TANK BOOST PUMPS ON. PILOT VERIFIED FUEL TANK BOOST PUMPS OPERATIONAL. VERIFIED FUEL PRESS IND READING PROPERLY. WHEN BOTH NR 2 FUEL TANK BOOST PUMPS WERE TURNED OFF, NR 2 FUEL PRESS WENT INTO YELLOW. REMOVED NR 2 ENG DRIVEN FUEL PUMP AND FND INPUT SHAFT COULD BE TURNED WITH NO MOVEMENT OF PUMP IMPELLER. REMOVED AND REPLACED FUEL PUMP. SHAFT SPLINES WORN ALLOWING IT TO DISENGAGE. MALE SPLINES OF THE SHAFT HAD SMALL AREA OF WEAR. LENGTH OF FEMALE SPLINES OF THE PUMP ARE SMALLER THAN LENGTH OF MALE SPLINES CAUSING WEAR TO BE CONCENTRATED ON A SMALL AREA. (X)