Hi. I'm not a mechanical person so I will try to explain this the best I can. I inherited a L3450 tractor from my dad and am cutting the surrounding fields with a Bush Hog. This Bush Hog has a grade 2 shear bolt in it from Tractor Supply. Yet a lot of times it doesn't break when I run over something big and instead the PTO just stops working. When that happens I can turn the Bush Hog shaft around freely in either direction by hand which I understand you should not be able to do if things are working correctly. Once I waited a couple of days and the PTO just started working again for no reason. But often what has to happen is I get this guy to open the tractor, remove the hydraulic fluid, knock the internal PTO shaft a few times with a metal bar until it locks and stops turning freely and then put the fluid back in and close it up. Then it works. The Kubota repairman actually showed him how to do this. But why isn't the shear bolt breaking? Any ideas what is going on here? There has to be a better way.