As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CLIMB , RED MASTER WARNING , RED NR 4 OIL PX WARNING, NR 4 OIL PX GUAGE IN RED. CREW ELECTED TO SHUTDOWN NR 4 ENGINE. AIRCRAFT RETURNED TO DEPARTING AIRPORT FOR NORMAL LANDING. INSPECTION FOUND OIL PUMP DRIVE GEAR IN GEARBOX SPLINES WORN, ALONG WITH WEAR ON OIL PUMP SHAFT RESULTING IN OIL PUMP NOT BEING DRIVEN. NR 4 ENGINE REMOVED AND REPLACED WITH SERVICEABLE SPARE.