speaking of a slip clutch,

BrettW · Mar 14, 2003

I have a 4' tiller and will soon have a 5' finish mower, but no slip clutch on either. Is this something I really need? Is it likely to damage my tractor if I hit a rocks/roots with either tool? thanks in advance, bw

tdenny · Mar 14, 2003

I believe that if you don't have a slip clutch then you will have a shear pin which should break before your tractor does.

cstocks · Mar 14, 2003

I think it is more a matter of what you want than what you need. Do you want the inconvenience of stopping and replacing a sheared pin everytime you break one, or the hassle of doing an operational check on your slip clutch everytime it has set up unused for a spell?

My Bush Hog manual says to check the slip clutch every time it has been stored for thirty days or more. For me that would mean checking it several times a year. On the other hand in a year and a half of mowing I have only sheared one pin, so for me a shear pin works best.

HayDR · Mar 14, 2003

Many MFG do not offer the clutches standard on the small tillers. It's hard to get a slip clutch that really works in 25-30 HP range because HP is a product of Torque and speed of motion. Most tractors have PTO clutches that protect both the implement and the tractor if they are properly matched.

grandad · Mar 16, 2003

You're probably OK with that finish mower, unless you make a habit of mowing after too many beers and can't seem to avoid hitting things. /forums/images/graemlins/crazy.gif Just kidding!

If you must till soil with lots of rocks, as my place seems to have, you may go through a lot of shear pins on that tiller, and you get to repeat the adventure each time you till until you somehow get the rocks out. I'm grateful for the slip clutch... without it I'd be buying shear pins by the gross.

JimMc · Mar 16, 2003

Most finish mowers are belt drive. In that situation, the belt functions as driveline protection.

BrettW · Mar 17, 2003

Where would the sheer pin typically be? bw

Bird · Mar 17, 2003

Brett, I don't know how many kinds there might be, so I can only tell you about the ones I'm familiar with. The PTO output shaft is splined and therefore the coupler on that end of the implement drive shaft is splined to fit on there. The other end (implement end) of the driveshaft is not splined, but smooth, as is the input shaft that it's connected to on the implement gearbox. The shear bolt goes through the coupler and gearbox input shaft. If it shears, you simply turn the driveshaft until it's lined up with the sheared bolt and drive the old bolt out with either a drift pin or the new shear bolt (assuming it didn't all fall out when it sheared). IF you should ever need to disconnect the driveshaft from the gearbox, you would have to remove the shear bolt. Then there is a snap ring on the end of the gearbox input shaft. You have to get to it between the coupler and the u-joint and it has to be removed before you can get the coupler off. That's what keeps the driveshaft from coming completely loose when a shear bolt shears.

If anyone has one that's different, maybe you can describe it.

BrettW · Mar 17, 2003

thanks Bird, FYI, I saw a bald eagle today out over the Chesapeake Bay, figured you'd like that. They are pretty impressive. bw

Bird · Mar 18, 2003

Yep, the bald eagles are certainly impressive and fun to watch. I saw lots of them in Alaska, but have only seen one, personally, down south many years ago at Lake Texoma. I've heard they can be seen at Lake Belton in central Texas, but I've only been there once long ago and didn't see any.