I am still getting used to my new used Deere 4400 and am having trouble with the PTO. I am in shopping for an owners manual right now. My question is when I turn the PTO on both the mid shaft and the rear are turning. I am assuming if I push down on the round knob that will disengage the mid pto, my problem is that it wont go down. Am I missing something or what do I need to do to adjust its attitude. Thanks