What was found
CLIMBING OUT OF 5,000 FT, AUTOPILOT WAS ENGAGED THEN DISENGAGED WITH AN ABRUPT PITCH UP MOMENT. SHORTLY AFTER RETRIMMING, A/P DISENGAGED AGAIN, BUT WITH NO PITCH CHANGE. IT WAS DECIDED NOT TO RE-ENGAGE THE A/P. A SHORT TIME LATER WE RELIZED THAT WE HAD A JAMMED STAB AT -1.3. WE FOLLOWED THE APPROPRIATE CHECKLIST. BURNED FUEL TO LAND, LESS THAN 27,000 LBS AND LANDING WITHOUT INCIDENT. REMOVED AND REPLACED HORIZONTAL STAB. ACTUATOR ECM WITH MODIFIED ECM IAW CESSNA 750MM. 27-40-00.