Bush Hog PTO Clutch

kc5gxc · May 18, 2008

Howdy
I installed a clutch on pto for bushhog and did away with the shear pin.
The seller of the clutch says don't try to adjust it. (Sent bolts with it to do away with shear pin....) I want this thing to work if I get on a stump or something. Have any of you guys ever heard of adjusting one of these? Am sure this one fits many different HP tractor implements and how can one setting protect all HP levels? Or , in this case, does HP matter?
Just wondering about it....it's got the ring of bolts with springs that compress the clutch plate. Standard, I think.
Thanks for any insight......Pete/MS

Farmwithjunk · May 18, 2008

kc5gxc said:
Howdy
I installed a clutch on pto for bushhog and did away with the shear pin.
The seller of the clutch says don't try to adjust it. (Sent bolts with it to do away with shear pin....) I want this thing to work if I get on a stump or something. Have any of you guys ever heard of adjusting one of these? Am sure this one fits many different HP tractor implements and how can one setting protect all HP levels? Or , in this case, does HP matter?
Just wondering about it....it's got the ring of bolts with springs that compress the clutch plate. Standard, I think.
Thanks for any insight......Pete/MS

Do you know the BRAND of the slip clutch?

bjcsc · May 18, 2008

Not only should you adjust it, but they have to be maintained - esp. if you store your bush hog outside. Fwj is asking about the brand so he can give you the correct spring lengths.

Basically, at the start of every season you loosen the bolts until the springs bounce around. Mark the plates (silver Sharpies or soapstone work great), lower the cutter down onto something (piece of a 6x6, firewood, log whatever) engage the PTO (idle RPM) so the clutch slips. Verify that is slipped by checking your marks. Slip it a few times and then adjust the springs back to the correct length.

pitt_md · May 19, 2008

I am not quite so scientific about the slip clutch maintenance. I just back off the tension a couple turns and engage the PTO. I can hear it slipping (squealing) and then retighten back to where they were.

I wonder if a torque reading wouldn't be more accurate than a spring length?

mjfox6 · May 19, 2008

Here is the table I use, I downloaded it off of TBN some time ago.

kc5gxc · May 19, 2008

Howdy again.
Here's the brand of slip clutch....EUROCARDAN.........Got from Agri Supply. Paper catalog and online. Was almost exactly 1/2 the price of one that looked just like it at local tractor supply place. Appears to be a high quality and well built device. Came with 2 hard steel bolts to mount and replace shear pin.
Probably made in Outer Mongolia or somewhere, doesn't say on it.
I marked it from the get go to see if it was gonna slip. No slip....then I loosened up the springs a bit as I was leery of it not saving my tractor/hog if I hit something. Called them and they said do not tamper with settings ???
A long time ago I saw the lower back end busted open from a bush hog and a no shear hard pin installed. My basic plan is to keep loosening until I get a little slip and then tighten to stop slipping (under hard cutting conditions....ie...real tall, thick grass/hay.
I saw the spring chart. How in the heck would one measure to such a careful degree on something like this.....and with what?????
Thanks for the help......Pete/MS

bjcsc · May 20, 2008

kc5gxc said:
My basic plan is to keep loosening until I get a little slip and then tighten to stop slipping (under hard cutting conditions....ie...real tall, thick grass/hay.
Thanks for the help......Pete/MS

That will work. Just make sure you do that at least once a year

kc5gxc said:
I saw the spring chart. How in the heck would one measure to such a careful degree on something like this.....and with what?????

That chart is actually Eurocardan's chart. You measure it with calipers...

Highbeam · May 21, 2008

"My basic plan is to keep loosening until I get a little slip and then tighten to stop slipping (under hard cutting conditions....ie...real tall, thick grass/hay.
"

That's what I do. I loosen it up at the beginning of the season and let it slip until it gets good an warm which burns off rust and gunk. I then tighten the bolts until I can't spin the springs by hand and then mow. I usually have to tighten a little bit more to eliminate slippage under normal conditions. You will learn to recognize the sound of a slipping cltuch and then the sound of the blades spinning back up to PTO speed. That shouldn't happen very often in a nice field but mroe often if you are mowing trees and rocks. When you think you have got it right, stop the mower and put your hand on the clutch to feel for heat. It should be cold indicating no slippage.