Hello, glad to be back on the tractor sight. I have been servicing up my Ol super 55 here lately greasing, tuning etc. etc. Today thought I'd drain the oil out of the trans. top cover at the 1/4" plug. Now eighter I am blind or can not find a procedure to bleed the the system, it does show you how to bleed the external valve system with the hoses. So my guess would be to connect a hose back to my 1/4" port say with a nipple of some sort and start her up and cycle the control lever back in forth until there is clear oil without any bubbles. I filled it up with straight 30 weight. Thank you.