As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF FROM HIK CREW NOTED #2 "ADI" ATITUDE DIRECTIONAL INDICATOR ROLLING RANDOMLY. AS PRECAUTION CREW ELECTED TO RETURN TO HIK. AFTER AN UNEVENTFUL LANDING. MAINTENANCE TROUBLE SHOT AND REPLACED THE GYRO PER THE ATI DC-8 MAINTENANCE MANUAL AND E.O. 34-DC8-1806 UPON GROUND TEST SYSTEM CHECKED NORMAL AND THE AIRCRAFT WAS RELEASED FOR SERVICE.