I have a Walker chuck off an old DoAll G10. It seems to be weak and is very hard to move the lever which is on the short side of the chuck. I took it off and removed the screws from the bottom side and the top piece came off but it appears that the bottom section is sealed up and I'm not sure how to open it. It appears that it the top section may be pinned in when I look at the sides. Any idea how to get this apart? Not sure I will be out anything if I break it as I can slide pieces of metal across it when magnetized.