What was found
UPON GEAR DOWN SELECTION, LOUD (EXPLOSIVE) BANG CAUSED AIRCRAFT TO SHUTTER VIOLENTLY ALL INDICATIONS NORMAL. FOUND RT MAIN LANDING GEAR ACTUATOR PIN BROKEN SECURED ACTUATOR TO GEAR. INSTALLED 3 GEAR PINS AND SAFTIED. I HAVE INSPECTED THIS ACFT AND FOUND IT SAFE FOR FLIGHT INTENDED. REMOVED AND REPLACED RIGHT MLG RETRACT PIN AND REWORK OF MLG PIN BOSS IAW S/B 32-102 AND APPROVED 8110-3 DATED 04/13/99. GEAR SWING C/W PER DC-8 M/M 32-10-00. OPS CHECKS GOOD PER DC-8 MM 32-10-00.