What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The pilot reported; while in normal cruise at FL 400, approximately 4+30 into the flight the white advisory annunciation autopilot fail occurred. The autopilot switched from channel 1 to channel 2. A few minutes later the same annunciation occurred and the autopilot switched from channel 2 to channel 1. About 10 minutes later the yellow caution annunciation roll mistrim occurred and the autopilot was kicked off. He hand flew and determined that the trims were set properly for straight & level. However, he found that it was difficult to turn left for a minor heading correction. Pitch was ok and a right turn was normal, but he had to exert more than normal force to the left until the binding suddenly released and the wings jerked to the left. After that the control forces were normal in both directions, so after about 5 minutes hand flying he re-engaged the autopilot and continued normally. After about 10 more minutes the yellow caution annunciation roll mistrim occurred again and the autopilot kicked off again. Again it was difficult to turn left until more than normal pressure was exerted on the control yoke in order to unbind the aileron, and then the controls were normal. Now thinking there was an autopilot issue, he decided to descend to FL 280, below rvsm, and hand fly the rest of the way (now just over an hour remaining) into kvny. Now at FL 280, in about another 10 minutes, the left turn binding occurred again. Now knowing it was not the autopilot, but not knowing what was the problem, they decided to declare an emergency and divert to Phoenix-kphx airport. The binding occurred 2 more times in the descent, with the last time at about 6000'. After getting the binding to release that time, the rest of the flight and landing were normal. Safely on the ground they cancelled the emergency and taxied into parking normally.
As the FAA filed it
THE PILOT REPORTED; WHILE IN NORMAL CRUISE AT FL 400, APPROXIMATELY 4+30 INTO THE FLIGHT THE WHITE ADVISORY ANNUNCIATION AUTOPILOT FAIL OCCURRED. THE AUTOPILOT SWITCHED FROM CHANNEL 1 TO CHANNEL 2. A FEW MINUTES LATER THE SAME ANNUNCIATION OCCURRED AND THE AUTOPILOT SWITCHED FROM CHANNEL 2 TO CHANNEL 1. ABOUT 10 MINUTES LATER THE YELLOW CAUTION ANNUNCIATION ROLL MISTRIM OCCURRED AND THE AUTOPILOT WAS KICKED OFF. HE HAND FLEW AND DETERMINED THAT THE TRIMS WERE SET PROPERLY FOR STRAIGHT & LEVEL. HOWEVER, HE FOUND THAT IT WAS DIFFICULT TO TURN LEFT FOR A MINOR HEADING CORRECTION. PITCH WAS OK AND A RIGHT TURN WAS NORMAL, BUT HE HAD TO EXERT MORE THAN NORMAL FORCE TO THE LEFT UNTIL THE BINDING SUDDENLY RELEASED AND THE WINGS JERKED TO THE LEFT. AFTER THAT THE CONTROL FORCES WERE NORMAL IN BOTH DIRECTIONS, SO AFTER ABOUT 5 MINUTES HAND FLYING HE RE-ENGAGED THE AUTOPILOT AND CONTINUED NORMALLY. AFTER ABOUT 10 MORE MINUTES THE YELLOW CAUTION ANNUNCIATION ROLL MISTRIM OCCURRED AGAIN AND THE AUTOPILOT KICKED OFF AGAIN. AGAIN IT WAS DIFFICULT TO TURN LEFT UNTIL MORE THAN NORMAL PRESSURE WAS EXERTED ON THE CONTROL YOKE IN ORDER TO UNBIND THE AILERON, AND THEN THE CONTROLS WERE NORMAL. NOW THINKING THERE WAS AN AUTOPILOT ISSUE, HE DECIDED TO DESCEND TO FL 280, BELOW RVSM, AND HAND FLY THE REST OF THE WAY (NOW JUST OVER AN HOUR REMAINING) INTO KVNY. NOW AT FL 280, IN ABOUT ANOTHER 10 MINUTES, THE LEFT TURN BINDING OCCURRED AGAIN. NOW KNOWING IT WAS NOT THE AUTOPILOT, BUT NOT KNOWING WHAT WAS THE PROBLEM, THEY DECIDED TO DECLARE AN EMERGENCY AND DIVERT TO PHOENIX-KPHX AIRPORT. THE BINDING OCCURRED 2 MORE TIMES IN THE DESCENT, WITH THE LAST TIME AT ABOUT 6000'. AFTER GETTING THE BINDING TO RELEASE THAT TIME, THE REST OF THE FLIGHT AND LANDING WERE NORMAL. SAFELY ON THE GROUND THEY CANCELLED THE EMERGENCY AND TAXIED INTO PARKING NORMALLY.