What was found
DURING REPLACEMENT OF RT MLG ATTACH FITTING (TRUNNION) WHILE INSTALLING LOWER REAR AUXILIARY SPAR CAP TO TRUNNION, 'NEW CONDITION' BOLT, P/N NAS-638-39, CRACKED WHILE TURNING INTO POSITION. THIS BOLT WAS ONLY BEING RUN IN AT TIME OF FAILURE, NOT TORQUED. ACFT N NR HK-4176X.