As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, NR 1 CONSTANT SPEED DRIVE LOW OIL PRESSURE LIGHT ILLUMINATED FOLLOWED BY RISING OIL TEMPERATURE. DISCONNECTED CSD AND RETURNED TO MFM FOR A SAFE LANDING. REPLACED CSD IAW MM 24-11-11 PG 401 AND CSD OIL COOLER IAW 24-11-21 PAGE 401. AIRCRAFT RELEASED FOR SERVICE.