rototiller

To my knowledge no tractor comes with a slip clutch as standard equipment, my guess is because it's application is limited. However, there are tons of them offered as aftermarket add-ons. Here is one sample.

http://www.gaequipment.com/Sli…..45qdtl.htm

PTOs that I have seen were all splined on both ends and any shear pin or slip clutch was on the implement between the input shaft and the first gearing or other drive part.  I've never seen a PTO shaft that had a smooth end with a shear pin or bolt, though that doesn't mean someone somewhere doesn't use one.

Come to think of it, I believe the rototillers have a shear bolt on the tine shaft.

Bob is right, you should have shear bolts on the tines, just like my 6hp walk behind tiller. My Lienbach post hole auger uses 3/8″ grade 5 sheer bolts just after the PTO, they get a lot of use around here. If you were to put in a slip clutch it would still go on the tiller, not between the splines of the PTO.

Dogdoc:

I guess what I meant to say was the pto shaft was splined on both ends and thus seems as though there is no safety  mechanism for a jam (rock,log,etc..) which gets caught up in the rototiller blades.  The way I see it either the engine stalls or there is serious mechanical failure somewhere.  So should I install a slip clutch??

Check the shaft ends that the tines (“blades”) are welded to, there should be bolts going through the shaft and a sleeve coming from the right-angle gearbox. This IS the safety mechanism. Like Tinbender said, only use grade 5 or less as a shear bolt otherwise you WILL damage something. You can install a slip clutch if you want to, it won't keep the shear bolts from shearing, but you'll feel better anyway.

my 4 ft king kutter came with a slip clutch from the factory.but if you add one make sure that you have clearance these shafts are very short so check it out before you start cutting