Interesting. I always use an over running ratchet clutch on any implement that don't have one built into the driveline, my bat wing mower for one and never had issue one with it. Seems to me that it would take a serious wham bam to break one off. Of course I do make sure my driveline never becomes an interference fit to the stub shaft or the ratchet clutch but I'd think jamming it from lack of shaft clearance would destroy the seal before anything else. I'm always especially cognizant of swing clearances too. On my disc mower. NH provided wheel shields just to prevent that from happening, you get up against the shield before anything bad happens and yes, I've removed the paint from them before.
An over running clutch on any freewheeling implement is almost a necessity on a larger Kubota's because the PTO brake on them is weak and always has been. Not sure about other makes but on large frame Kubota it is and necessitates an over running clutch on any implement that free wheels when toe PTO is disengaged. I know Kubota issued a RO on them but I was never made aware of it (shame on my dealer). Too late now (by a few years) to have it done and it's a very involved process as the PTO clutch pack is only accessible with a split. Like I tell people, you can see it if you pull the back pto carrier casting off, but you cannot reach it to do anything to it.
Was more curious as to how you can break a PTO stub off. Like I said, never have put I guess anything is possible, when you don't think about an application and check the swing angles.
On over running clutches, I use a heavy duty (greaseable one) that is rated for 130 pto horsepower. Most of the ones available on Flea Bay or Amazon are only good for 50 horse maximum, which, in my case isn't enough.
