Your mule drive looks different than mine - almost looks like someone hacked the tabs off the front. But then again, it may be off a different model that I haven't seen...
anyways, the tabs go in the ears, the back of the mule drive has the holes where the spring loaded pins go. 3/4 way back you can see the one hanger, looks like you're missing the other one - they hook underneath to the levers connected to the rock shaft for lifting / lowering. The pronged end slips over the rod mounted to the tractor underneath, (it's probably got wear to it where it rides) you'll see it - pretty self-explanatory.
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