There's a lot of soil engauged PTO powered equipment here. Put your tractor on a power harrow or bed tiller, run it at full load for 6 weeks in a cloud of dust then try to get the PTO off. Even if you take them off every day to grease the shaft they can get stiff. I've even had groove of the tractor PTO that's made removing the PTO shaft very difficult and time consuming and have never found an easy way of getting it to part company with the tractor. My colleague could well use his every time he takes the power harrow off, because the shaft on that is bloody heavy