backwoods07 Posted September 21, 2009 Report Share Posted September 21, 2009 (edited) This past weekend we started to till some land up on our farm to put in our winter plots (a little late, I know). We made it through about 10 minutes before shearing the lock pin that holds the driveshaft of the tractor to the tiller. No big deal, it's supposed to happen, right? Well, after about 8 hours and 30 shear pins later, we decided to call it quits. We tilled up about .5 acres. We have an 18hp Kubota BX1850 with an RTR05 Rotary Tiller. It's supposed to have a slip clutch so the driveshaft shear pin doesn't get the brunt of the shock, but it seems like the pin breaks every time the blades hit the ground. The land that we were tilling wasn't full of debris or tree roots or anything of that sort that would cause these pins to break. It was grass on the edge of a corn field after a rain. No clogging, no build up. Has this happened to anyone before? Are we doing something wrong? Any advice or input would be greatly appreciated. Here is the type of pin I'm talking about. They're 1/4" stainless steel. Edited September 21, 2009 by backwoods07 Quote Link to comment Share on other sites More sharing options...
ksbowhntr77 Posted September 21, 2009 Report Share Posted September 21, 2009 Is the pin that keeps breaking on the pto before the slip-clutch and does the slip-clutch work like it's supposed to or is it locked up? The pin you have a pic of is just a 1\4" lynch pin..... those weren't meant to act as a shear bolt. Most shear bolts should fit the hole they go in snugly so as to not have any play between the bolt and the hole and are usually if not always a grade 5 bolt. Without seeing where the pin is located on the PTO that's all I can come up with for now.... KS Quote Link to comment Share on other sites More sharing options...
wtnhunt Posted September 21, 2009 Report Share Posted September 21, 2009 Would check to be sure you are getting the right pin(right hardness and size) and also check the tiller to be sure there is not something you are not seeing with it attached to the tractor that is maybe binding up. My understanding when using a slip clutch, most often you do not also have a shear pin, use one or the other. I know that all of the implements I own or have used including a tiller that have clutches have no shear pins at all on the drive shafts. Quote Link to comment Share on other sites More sharing options...
backwoods07 Posted September 21, 2009 Author Report Share Posted September 21, 2009 Is the pin that keeps breaking on the pto before the slip-clutch and does the slip-clutch work like it's supposed to or is it locked up? The pin you have a pic of is just a 1\4" lynch pin..... those weren't meant to act as a shear bolt. Most shear bolts should fit the hole they go in snugly so as to not have any play between the bolt and the hole and are usually if not always a grade 5 bolt. Without seeing where the pin is located on the PTO that's all I can come up with for now.... KS I'm not really sure what to check with the slip clutch? I figured it might be something with that but I didn't know where to start. We went through 3 shear pins specifically designed for the tractor and implement, but at $7 a piece, we stopped buying those and just went with the $.79 pins. My understanding when using a slip clutch, most often you do not also have a shear pin, use one or the other. I know that all of the implements I own or have used including a tiller that have clutches have no shear pins at all on the drive shafts. From what I understand, the shear pin is a backup for the slip clutch in case the clutch fails. Without the shear pin, I don't think the tiller would spin. Any idea on what to look for if the slip clutch is malfunctioning? Quote Link to comment Share on other sites More sharing options...
ksbowhntr77 Posted September 21, 2009 Report Share Posted September 21, 2009 Would check to be sure you are getting the right pin(right hardness and size) and also check the tiller to be sure there is not something you are not seeing with it attached to the tractor that is maybe binding up. My understanding when using a slip clutch, most often you do not also have a shear pin, use one or the other. I know that all of the implements I own or have used including a tiller that have clutches have no shear pins at all on the drive shafts. He's right, the parts manual online doesn't show both, just one or the other...... so IF there is a shear bolt in the PTO line I would be safe to say you are using the incorrect hardness and size bolt for the job. It also could go hand in hand with the way you engage your tiller and the tiller to the ground. I.E. if you drop it and don't ease it into the ground somethin's gonna give hence the broken pin.... also if you drop the clutch on the tractor and engage the tiller to operating rpm without working into it, you create unnecessary torque on your driveline and hence shear the pin..... Quote Link to comment Share on other sites More sharing options...
wtnhunt Posted September 21, 2009 Report Share Posted September 21, 2009 From what I understand, the shear pin is a backup for the slip clutch in case the clutch fails. Without the shear pin, I don't think the tiller would spin. Any idea on what to look for if the slip clutch is malfunctioning? Clutch will slip if it gets under too heavy a load, that is what it is designed to do, really not much that could happen in the way of it failing other than it stalling out the tractor if it gets under too heavy a load and it was over rated for the tractor. That is where the hp rating for your tractor should fit the rating for the tiller. Like I said before, I would not think that you should need both the clutch and the shear pin, but looks like the tiller if it is the land pride did come standard with the shear pin and with the option for slip clutch http://www.landpride.com/ari/attach/lp/public/specs/311-464s.pdf. Might contact landpride and see what they have to say http://www.landpride.com/contactus/contact_service.html. Might ask about doing away with the shear pin setup. Without seeing your drive shaft in front of me, not sure how you could get around it, but sure since you have the clutched driveline I believe that you could go with a non shear pinned driveline. Think if it were me, I would ask landpride and see what they suggest. Quote Link to comment Share on other sites More sharing options...
wtnhunt Posted September 21, 2009 Report Share Posted September 21, 2009 Go to pages 16 to 20 here http://www.landpride.com/ari/attach/lp/public/manuals/311-464p.pdf. The manual calls for the driveline to be setup one way or the other. If you look at the bolt(part #24) for the shear pin it is a bolt and nut, not a lynch pin. Kind of sounds like maybe someone who sold the tiller put on the option of the slip clutches without changing out the rest of the driveline, and maybe someone broke or for whatever unknown reason replaced the shear bolt with the type pin you are using now. Quote Link to comment Share on other sites More sharing options...
backwoods07 Posted September 21, 2009 Author Report Share Posted September 21, 2009 Thanks a ton for those links. I contacted Land Pride and my local dealer. I searched everywhere for that parts manual. Good job findin it. I'm gonna try this out on Friday when I make it back to the farm. I'm gonna try that shear bolt and make sure nothing is jamming the driveshaft. Maybe I can give the previous owner a call to get more information for all you geniuses. Sometimes just explaining the situation to people that know what they're talking about gets you places. Thanks again guys!! Quote Link to comment Share on other sites More sharing options...
Texan_Til_I_Die Posted September 25, 2009 Report Share Posted September 25, 2009 Have you considered plowing the spot before you till it? Maybe a quick pass with a chisel or disk to loosen things up a bit? Quote Link to comment Share on other sites More sharing options...
redkneck Posted September 26, 2009 Report Share Posted September 26, 2009 We go through a lot of pins each year, no big deal, but just get some cheap grade 5 bolts and nuts, not a lynch pin. I'd much rather hop off the tractor for a second and put in a new bolt than tear up a tiller. We're using a lot more tractor than 18hp, though, and can damage a tiller fast. Quote Link to comment Share on other sites More sharing options...
dbHunterNY Posted September 26, 2009 Report Share Posted September 26, 2009 If the two plates or discs fastened together (the clutch) are exposed sometimes to can take paint or a permanent marker and make marks on the edges of the two plates. Then check it when you're out using it. Shut it down and if the marks aren't lined up then they aren't slipping so all the force when hitting a rock or something is going to those lynch pins which as some have said aren't as hard as a shear pin (bolt). Hope that helps but I'm not familiar with your piece of equipment. Quote Link to comment Share on other sites More sharing options...
gitcha_some Posted September 27, 2009 Report Share Posted September 27, 2009 Or just find out what size of bolt you need, then upgrade to a grade 8....we use them on our landscape rakes and it will still break them from time to time so they arent too tough Quote Link to comment Share on other sites More sharing options...
backwoods07 Posted September 28, 2009 Author Report Share Posted September 28, 2009 We go through a lot of pins each year, no big deal, but just get some cheap grade 5 bolts and nuts, not a lynch pin. I'd much rather hop off the tractor for a second and put in a new bolt than tear up a tiller. We're using a lot more tractor than 18hp, though, and can damage a tiller fast. That's what the guys at the dealer said to do. I guess I'd rather buy 100 pins at $.29 a piece than 3 grand on a new driveshaft Quote Link to comment Share on other sites More sharing options...
huntinman802 Posted October 23, 2009 Report Share Posted October 23, 2009 id hit it with a plow or a disc before if you have the equipment. are u talking about the power take off(PTO) ive never used a rotary tiller before but i am pretty good on most farm equipment. i would try a hardened bolt Quote Link to comment Share on other sites More sharing options...
redkneck Posted October 23, 2009 Report Share Posted October 23, 2009 Or just find out what size of bolt you need, then upgrade to a grade 8....we use them on our landscape rakes and it will still break them from time to time so they arent too tough id hit it with a plow or a disc before if you have the equipment. are u talking about the power take off(PTO) ive never used a rotary tiller before but i am pretty good on most farm equipment. i would try a hardened bolt You should never use a Grade 8 for a shear pin. That's supposed to be the weak link. Quote Link to comment Share on other sites More sharing options...
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