What was found
CREW REPORTED ON TAKEOFF, AFTER RAISING GEAR, LOUD CONSTANT BANGING NOISE COULD BE HEARD THRU OUT THE ACFT. LEFT MAIN LANDING GEAR INDICATION CYCLED BETWEEN IN TRANSIT (HASHED) AND UP. NO OTHER INDICATIONS, HYD SYSTEMS NORMAL. FOLLOWED QRH FOR LANDING GEAR/LEVER DISAGREE. CYCLED GEAR, CAME DOWN NORMAL WITH NORMAL INDICATIONS BANGING STOPPED. RAISED GEAR AND BANGING STARTED AND PREVIOUS EICAS LEFT GEAR INDICATIONS RETURNED. LOWERED GEAR NORMALLY AND LANDED. CORR ACTION 8/8/24 FOUND CMC MESSAGE STATING LH UPLOCK PROX SWITCH FAIL. REPLACED BOTH LEFT UPLOCK SWITCHES. PERFORMED GEAR SWING , CYCLED 3 TIMES, OPS CHECK GOOD. FWD LEFT PROX SWITCH: P/N OFF: 8-527-01. S/N OFF: A20361. P/N ON: 80-057-01AP S/N ON: 1315 AFT-LEFT PROX SWITCH: P/N OFF: 8-527-01. S/N OFF: A20495. P/N ON: 80-057-01AP. S/N ON: 1678. 8/9/24 CHECK FLIGHT FAILED. 8/10/24 REMOVED AND REPLACED L/H MLG UPLOCK BOX ASSY REMOVED AND REPLACED L/H MLG ELEC. UNIT. NO DEFECTS NOTED OPS CHECK GOOD. LANDING GEAR ELEC. UNIT P/N ON 355-022-003 S/N 5134 P/N OFF 355-022-003 S/N 1225. UPLOCK BOX ASSY P/N ON 2309-2900-401 S/N 737 P/N OFF2309-2900-401 S/N 822. 8/11/24 CHECK FLIGHT PASSED.