I bought a used a used Black & Decker drill that has no identification tag on it but, as far as I can tell, looks similar to a model 1321. I need to know if the chuck is just tapered or threaded. I removed the left hand screw inside but I don't want to break the front housing getting the chuck off. I'm taking it off because it looks like oil has been blowing out of the vents near the chuck. Maybe someone can help me with that problem too.