What was found
DURING FLIGHT, FL 330 & 300, THE LT & RT AUTO PILOT SYS DISENGAGED. ABLE TO REENGAGE THE SYS FOR ONLY 2 MIN BEFORE THE SYS DISENGAGED AGAIN. THE SYS WAS TROUBLE SHOT & IT WAS FOUND THAT MOISTURE WAS IN THE GREASE WITHIN THE ELEVATOR TRIM JACKS. THE SERVICE BULLETIN 27-3840 TITLED, IMPROVED GREASE FOR TRIM JACKS, TO PREVENT FREEZE-UPS OF THE JACKS HAD BEEN PREVIOUS COMPLIED WITH. THE TRIM JACKS WERE REMOVED, CLEANED, INSPECTED & LUBRICATED. THE TRIM JACKS WERE REINSTALLED & RIGGED IAW THE AMM. ALL OPERATIONAL CHECKS WERE SATISFACTORY.