I need to replace the cylinder in our front door lock (just bought the home and need to make sure nobody but us has the key). However, the screw that fixes the cylinder in place gets stuck. It gets progressively stuck, and so much so that it makes it very hard to get it to screw back in, and I don't dare try to force it further due to the risk of it just getting completely stuck.
I thought perhaps it was getting stuck in part of the door mechanism, so I unscrewed the front panels, and you can see the screw. It appears to be getting stuck just before the last part of the screw that sticks out at the end is about to enter the cylinder, and while I can't see anything wrong with it, I assume that means the screw is bent or the thread is damaged there, which would explain why it is so difficult to screw back in.
Other than calling a locksmith, my only idea is to take a small, narrow hacksaw and saw the end of the screw off through the slit next to the cylinder, and try again. Is this the right approach or is there something I'm missing (e.g. it's something entirely different, sawing the screw off might saw through some other part of the lock mechanism, or I'll never get the sawed off end out and it will break the mechanism)? Attached a video showing the screw inside the mechanism, and where it gets stuck.
Best Answer
Problem solved. It was indeed a cross-threaded screw as the comments said. I was afraid to get too enthusiastic about using pliers to unscrew it, in case it got utterly and entirely jammed halfway through. The local hardware shop said that in that case I could just take a hammer to the cylinder (after turning the key to where the pieces line up) to break the screw off and tap the cylinder out. So with that as a backup option, I used more elbow grease with the pliers and was able to unscrew it. No hammering required.