Clutch Type Sure-grip Chatter?

Been there and done that with the Royal Purple, I think its a wives tail or false advertising. I have a fresh rebuilt Power Lok in mine and it chattered after the first long drive in the heat at a bout 500 miles. At Dr Diffs recommendation I drained it and used GM modifier with some Lucas 75/140 then let it sit over night and it is excellent now. It was so bad that I was certain I broke a cross shaft and it is good as new with a fluid change. I would go ahead and run it for a good 500 miles or so before draining it though, might as well get it good and broke in first. Next question is did you put a drain in it when it was apart? lol!