WDB ACFT HAS MAIN GEAR SUPPORT TRUNNION BREAK ON LNDG ROLL.

Narrative

AFTER A VERY SMOOTH TOUCHDOWN ON RWY 31R AT JFK WITH ALL INDICATIONS NORMAL NOSEWHEEL WAS LOWERED AND ENGS REVERSED. AT THAT TIME OR SOON THEREAFTER ACFT WAS NOTICED TO BE SLIGHTLY L WING DOWN. SIMULTANEOUSLY THE FA AT L-3 DOOR RPTED WHAT SOUNDED LIKE AN EXPLOSION UNDER THE L WING. ACFT WAS SLOWED AND TURNED OFF AT THE LAST HIGH SPD TXWY AND STOPPED JUST CLR OF THE ACTIVE RWY. BRAKES WERE PARKED; ENGS SHUT DOWN AND GND CTL NOTIFIED TO DISPATCH THE RESCUE EQUIP. PA ANNOUNCEMENTS WERE MADE TO THE CABIN AND COMPANY AND MAINT NOTIFIED. PORT AUTH POLICE ARRIVED WITH STEPS SOME 10-15 MIN LATER AND PAX WERE DEPLANED FROM R-1 DOOR. WHEN COMPANY MAINT ARRIVED THEY ADVISED THAT THE L WING GEAR SUPPORT TRUNNION HAD BROKEN CAUSING THE GEAR TO GIVE WAY AND SLANT BACKWARDS. THE CREW THEN DEPLANED AND MAINT TOOK CTL OF THE AIRPLANE. NO INDICATIONS OR ANY PROBS WERE NOTICED ON PREFLT AT SAN JUAN. ALSO ALL INDICATIONS OF GEAR BEING SAFELY DOWN AND LOCKED WERE OBSERVED ON FINAL APCH AT JFK. WX WAS CLR AND DAYLIGHT.