I don't have a tiller...YET..so my guess is you should have a slip clutch on your PTO shaft. Most tillers seem to come with this style and I figure there is a good reason for it.
this tiller doesn't have a slip clutch. But, it should be able to actually till the ground. I'm missing something. I had a 40" Bush-Hog for years that never acted up, and it saw some rough treatment.
Yes most if not all brush hogs just have a sheer pin...mine does. The slip clutch is just something I see on all the new tillers I see and the one I will buy someday.
you are tilling either too deep, too fast, or in too hard a soil. Slow down, and make shallower passes followed by deeper passes. Hitting rocks can snap the pins also. Mike
I have broken one shear pin (found a buried "T' post) on my tiller and its time to change the tines. I would say something is wrong with your tiller/shaft or operation. I wonder if the gearbox or drive is ok. It should be easy to turn by hand (engine off/pto disengaged). If it isn't you need to figure out why. If it does I guess slow down and/or till shallower is the solution. Your bigger tractor can indeed cause some damage but I've abused mine some without a problem.