Hello, The keyless chuck on my Makita 6408 was jammed open, I couldn't loosen it with my hands. I held the static plastic with adjustable pliers and with another adjustable pliers gripped the plastic nose cone and tried to break the jam. There was a slip and the nose cone came off and a retaining ring fell out. Now the static cup is no longer static, it is loose, and I can't figure out where or how the retaining ring came from or how to put it back together. Can you instruct me? Again it is a newer Makita corded drill with a keyless chuck. Your help is appreciated.