As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 4 ENGINE OIL PRESSURE ERRATIC FLUCTUATES BETWEEN 0 TO 20 PSI WITH OIL PRESSURE LIGHT ON. ENGINE SHUTDOWN AS PER ABNORMAL CHECKLIST AND PROCEDURES. AIRCRAFT LANDED UNEVENTFUL. REMOVED AND REPLACED GEARBOX IAW MM 72-00. ACCOMPLISHED RUN UP, NO LEAKS NOTED. OIL PRESSURE FLUCTUATES. REMOVED AND REPLACED OIL FILTER HOUSING. ACCOMPLISHED RUN UP IAW MM 71-00. OIL PRESSURE NORMAL AND NO LEAKS NOTED. AIRCRAFT RETURNED TO SERVICE.