Hey all, I just bought a 63 Case 540 (gazoline) tractor and the previous owner told me he changed the PTO clutch disks few years ago, and when the pto is disengaged without load it still spins but stop when an implement is fixed, and engage fully when the lever is pulled. So I want to adjust the PTO so that when its disengaged it doesnt spin, and from the manuals I found on the web there should be a plug hole on the left side to pull pins to adjust, but on mine theres no plug on either side, only one big plug at the 12 oclock. I tried to push on the spring loaded pin thru the hole and turn the knob clockwise but it dont seems to make any difference. Anyone has any ideas on how to adjust my type of PTO ? Do I need to pull the entire case off ? I have the PTO with the lever on the side. Thanks yall !