When we had a 2350, it developed a squeak above the driver that continually got worse. I took it to the factory, and they took in on a test drive thinking I had a little rattle. When they came back, they agreed I had a SQUEAK. They took the cabinet above the driver apart and put additional screws where the shell attached to the Ford cab. After several test drives, more screws and a little over half a day, they had the problem fixed. I kept expecting the squeak to return, but it never did during the 2 years we had the 2350. Good luck on your squeak...I can certainly relate to your situation.