What was found
FLIGHT NR 6437 JFK TO AUS, T/O ROLL ABOVE V1 FELT VIBRATION/LOUD NOISE, LIFTED OFF RT MAIN GEAR WOULD NOT RETRACT. QRH CHECK LIST COMPLETED WITH NO RECOVERY. GEAR PLACED IN DOWN/LOCK POSITION. DECLARED EMERGENCY, ON LANDING "NIL BRAKING" USED THRUST REVERSERS TO STOP A/C. MTX REPORTS BRAKE LINE WAS DISCONNECTED BUT NOT SEVERED, RT INBD TIRE WAS SHREDDED, DOWNLOCK ACTUATOR BROKEN AND THE CASTING FOR 2 PROX SENSORS WAS BENT.