Shear Pin question

[GaryK]

chances are your tiller has a slip clutch if it stopped and the machine still ran. If you broke a shear pin you would know it, it makes a pretty good noise.

 

[GlennT]

I am just finishing putting in a cross-fence in a pasture and fencing off a creek. We have rocks of varying sizes embedded in our soil, so I have had several occasions to replace a shear pins on my Leinbach post hole digger. The PHD came with what appears to be a very standard PTO shaft--one made in Italy. It must be standard because it's similar to ones on my Bush Hog finish mower, my JD shredder and my Valby chipper. On the universal joint closest to the PHD, there's a small nipple which screws into the cast fitting over the PHD shaft and rides in a groove in the shaft. This nipple keeps the universal joint from slipping off the PHD shaft (and whipping around before you can stop the PTO). This nipple also keeps the hole in the universal joint lined up with the hole in the PHD shaft. You still have to rotate the universal joint to line it up with the hole in the PHD shaft, but you don't have to (in fact, can't) slide the universal joint back and forth on the shaft. The fairly soft grade 2 shear pins can deform slightly under pressure and after shearing a pin the part left in the PHD shaft can be a real bearcat to remove. The last one that I worked with couldn't be driven out with a punch. I finally had to drill down through the center of the broken bolt from both sides before I could drive it out with a small punch. I have learned to keep a couple of spare grade 2 bolts, a hammer and a couple of punches in the tool box (one the exact size and other much smaller than the shear pin) so I don't waste so much time going back to the shop. By the way, I sheared a pin on the very first hole. BUMMER! Good luck.

 

[Trev]

</font><font color="blue" class="small">( Bob, if you sheared a pin, the PTO shaft would continue turning and usually no load on the engine. If you have a slip clutch you should be able to see it on the PTO driveshaft to the tiller, should be towards the tiller end of the shaft. )</font>

Thanks, Bird. From this, I gather that the shear pin is part of the implement rather than part of the tractor.. if the PTO would still turn given a sheared pin. So the tractor doesn't have the sheer pin, the implement or the implements PTO shaft has the pin? I'll have to go take a good look...

Thanks again!

 

[Gary_in_Indiana]

Trev,

The shear pin is usually pretty easy to find on the implement as it's right at the connection point for your PTO. Just look for an odd bolt sticking out too far and that'll likely be it.