What was found
CONFIGURING AT DESTINATION, MOVING FLAPS LEVER FROM 15 TO 20, GOT A TRAILING EDGE FLAP DISAGREE EICAS MESSAGE, ALTITUDE 2,500FT, SPEED 170KTS. DISCONTINUED APPROACH, RAN QRH, AND LANDED FLAPS 20 UNEVENTFULLY. EMERGENCY DECLARED. R & R LT INBOARD TRAILING EDGE FLAP TRANSMISSION IAW AMM 27-51-06. R & R LT I/B FLAP, I/B TORQUE TUBE THAT RUNS FROM INBOARD FLAP TRANSMISSION UP TO ANGLE GEARBOX IAW 27-51-25-2-0. R & R LT INBOARD TRAILING EDGE FLAP BALLSCREW & GIMBAL IAW MM 27-51-11-4. OPERATED FLAPS UP AND DOWN WITH NO DEFECTS FROM 0 TO 30.