What was found
ON T/O, ROTATION FELT VIBRATION IN YOKE. GEAR HANDLE UP BUT GEAR DID NOT RETRACT. ECAM L/G WOULD NOT RET, AT DROPPED OFF AND WOULD NOT RESET. GPWS FAULT LIGHT ON. REMOVED AND REPLACED PROXIMITY DETECTOR UNIT PER MM 32-31-71-4 PG 401. NO FAULTS ON BITE.