As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT NOTED THAT ON APPROACHES WITH THE AUTOPILOT DISENGAGED, THE ELEVATOR CONTROLS WOULD CATCH WHEN SLIGHT ADJUSTMENTS WERE MADE. THE SMALL AMOUNT OF PRESSURE NEEDED TO BREAK IT LOOSE WOULD CAUSE THE AIRCRAFT TO PORPOISE A FEW TIMES. SUSPECT INTERNAL PROBLEMS IN THE SERVO MOUNT ASSY.