Actually, Eric brings up a good point....are you sure the fractures in question aren’t caused by bolts that are too long for the application and bottoming in the holes? That situation would potentially lead to joint failure.
I have seen it in other highly loaded joints.
Remember, the backhoe is installed at the dealership, not the factory.
ffs, you guys are posting without reading the original description providing the whole situation and analysis found linked in post #23.