My shift controller was loose to begin with. It had trouble going into reverse, you would have to play with it. I believe it was the controller anyway. Yesterday I drove about 300 yards to the fueling dock. I felt a vibration that lasted for about 3 seconds and cleared up. I went to the dock and refueled. I drove back to my wet slip and the boat wouldn't go into reverse. The handle appeared to be even more loose. Then eventually it wouldn't disengage from gear and would go forward whether it was in reverse, neutral, or forward. I called a mechanic and he said it was the lower unit, but I was wondering if this would be symptoms of a bad controller, even if it was loose before. And how would I test this? It's a bravo 1 outdrive with a 350 mercruiser.