Ford Super Duty (1999-2016) :: Key Won't Move To Off Position After Cylinder Lock Removal And Installation

I have a problem with an 2000 F250 7.3 6spd. Recently, the "key in the ignition" chime kept dinging even when no key was in the ignition. I read in the forums that a wire can be disconnected to stop the chime. The problem is that after I re-install the cylinder lock, I cannot move the key to the off position to remove the key. I can rotate it to start and run, but it won't move backwards to the off or acc position.

The truck has this little lever that normally needs to be pushed to allow key to be released, but even after pushing that, turning the steering wheel back and forth, and messing with the tilt, I still can't get the key into the off position. I have removed the cylinder and it looks good. It rotates properly and I can remove the key, but only when it isn't installed. I tried replacing the ignition switch, but the lock cylinder still doesn't move.

I have an 04 F250 that I've tried swapping the lock cylinders from the 04 to the 00, but it still doesn't turn. What might be the cause/fix? Also, the 2000 F250 has a intermittent chirping/squeaking sound under the dash that happens even when the batteries are disconnected - might this be a malfunctioning vacuum motor? It happens even though the truck hasn't been driven for a week.