I only have a rear PTO shaft for my tiller. After it sits for 6 months it get's stiff with grease on it. I give it a shot of WD 40. That thins the grease so it slied nice. It is still protected form the weather with grease.
Eddie might have the same problem that a lot of us have. When you use different PTO driven attachments, the male on the rear of the tractor is going to stop at a different position after use. The male is then no longer in the "line up" position from the previous implement. Don't you have to rotate the shaft to line up when you go to reattach the first mower? This is the biggest struggle I have. When I get the splines in the correct alignment, they always slide on very easily.
That's what big screwdrivers or tire irons are for... aligning yokes! ( they inexplicably also work for large screws and tires! )
soundguy