When changing the settings on the driver head of a 915/913.... does the little rubber O ring go up /down the neck of the head and is on the opposite side of the titanium screw and it's beveled washer ?

I saw a tip about putting the O ring on top of the adapter and inserting it upward into the head instead of trying to drop it down the neck and center it. Made me wonder if I was installing the head correctly.

Thanks for the help.