I haven’t had a moment to put this together, but here’s the answer, and why.
The locking collar needs to be rotated in such a way that the naturally occurring forces inherently tighten it, rather than loosen it. Now with that said, looking at the end of the crankshaft as seen from the front of the tractor (looking at the PTO clutch) the crankshaft rotates to the Left, counter clockwise.
So now consider the bearing for a moment. The inner part of the bearing that slides on the crankshaft (inner race) can spin freely in either direction. The locking collar prevents that rotation of the inner race on the crank shaft. That collar can be rotated in either direction to lock the bearing to the crankshaft. So when the crankshaft rotates counter clockwise the resistance that may occur (mostly only if the bearing isn’t spinning freely) is trying to turn the inner race of the bearing on the shaft in a clockwise direction. Therefore the locking collar should be rotated in the opposite direction of that force to maintain its hold. That direction would then be counter clockwise, or more simply said in the same direction as the crankshaft rotation, like the manual says.
The reason for this is because if the bearing fails, and sizes, it will apply force in opposes direction of the crankshaft rotation, and therefore help insure that the PTO doesn’t fly off. The reality is that if the bearing rotates freely there won’t be any resistance, and with that either way you lock the collar won’t matter, as it just keeps the race from spinning on the crank and wearing it out. That resistance is negligible under normal conditions, and that’s why it’s not a big issue. But the most redundant way for safety purpose is to lock the collar in the direction of crankshaft rotation. As in the event of a bearing failure it will reduce the chance of the inner race galling the crank, and potentially help keep the PTO from smacking you in the face.
My hang up was that I wasn’t considering the bearing failure. I was thinking of the inner race, and crank turning as one (since you don’t want them to move independently), and that the rotation to the Left of that unit should require the locking collar to be tightened in the opposite direction of rotation (clockwise). But when I considered the other possibilities, I realized the truth. And that’s all I was looking for.
I hope this helps others.
Mike
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