The JD 400s seem to have two different designs for the fittings where you drain the oil. One type is definitely a cap, and it has to be screwed completely off. One I found today that I haven't worked with before is a fitting with a T bar on the outer face of a cap. I was able to turn the T bar fitting enough to get oil dribbling out. Given the tight clearances and the fact this fitting is "buried" behind a hole in the frame, I'm not sure I'd ever get it back on again if I took it off. My question is: do I need to take it off to drain the oil reasonably quickly? Is there a stop of some kind to help keep me from inadvertently running it all the way off? Is there a downward looking hole that turning the T bar outward clears progressively, so that more fluid will come out the more turns I give the T bar? If for some reason I have to run the t bar cap all the way off to get a reasonably fast fluid drain, I may be in trouble with getting it back on. Anyone been there done this that can give me some help on this?