OK. it happen again !! for those of you that don't know; this happen to me last year. South Bend heavy 10. bison chuck. i had finally gotten the chuck off (last fall ) i think. since then i took it off once to use a collet. no problem getting it off then. need to get it off again. it won't budge!! i WILL get it off sooner or later. the question that i have at this time is. is there anything that i can do to prevent this from happening again. yes the threads are clean; and, no i didn't "jam " it on. would grease help. how about a dry spray lube. any suggestions?? until last falls stuck issue there has never been a problem. have had it off only around 8-10 times, but , never a problem. whenever i do get it off i think i'll make it a weekly ritual to loosen it. i now fear my heavy 10.