What was found
TE FLAP DISAGREE/AT FLAPS 20. RAN QRH TE FLAP DISAGREE WHICH TOOK US TO FLAP ASYMMETRY. LANDED FLAPS 20. NO ROLL NOTICED IN FLIGHT. REMOVED AND REPLACED NR 1 AND NR 4 FLAP TRANSMITTERS IAW AMM 27-51-45-2. REMOVED AND REPLACED LEFT FLAP/STAB POSITION MODULE ASSY IAW AMM 27-58-01-4. REMOVED AND REPLACED FLAP /SLAT ELECTRONICS UNIT IAW AMM 27-51-01-4. PERFORMED TRAILING EDGE FLAP POSITION INDICATION ADJUSTMENT/TEST PER AMM 27-58-00-5. OPS NORMAL. THIS WAS SDR EVENT PARTS CHANGE IDENTIFICATION REQUIRED PER GMM, REFERENCE TSI 27-50/4023.