Slip Clutch Advice

[Impaled]

First off I have a very old, very homemade 6' cutter. It has what appears to be a Bush Hog brand gear box and frame that has been welded to a home made deck. It belonged to my grandfather and I have since re-comissioned it and used it seasonally for the past 7-8 years. This whole time I always assumed it had a shear bolt because you could see the yolk and how it appeared to be bolted to the input shaft just like every other cutter i have ever used or been around. Well, after prepping the cutter for paint, I discovered that the yolk and inputshaft for the cutter and splined, so there is no shear feature whatsoever for this cutter.

I am very lucky that I have not destroyed my pto shaft, or even worse my pto driveline inside my tractor.


I want to add a slip clutch to my cutter, but I can not find any kind of specifics on what size, type, or any info of the sort that will direct me on my purchace.


I know I want a clutch that has two bolts that pretty much clamp the female end of the clutch to the male end of the cutter, but I do not know what size clutch I need.


The majority of my cutting is pasture land, but I do have a tendancy to back over some pretty thick brush from time to time. Well actually more of a pretty regular basis. Like I said Ive been very lucky up to this point...

if anyone has any experience/advice that would be great!

 

[pmsmechanic]

I would stop at a local dealer and look at slip clutches on cutters similar to yours. If you find one with the same shaft sizes that your machine has then just order one from the dealer. Or you can look online for pto slip clutches and order one with the proper shaft and horse power size.

I needed repairs for the slip clutch on my 660 rototiller. It was cheaper to order a new after market one than to get parts from John Deere.

 

[Impaled]

Thanks for the advice. I have searched high and low, but not all of the online results give detailed info.

all I can count on from the local dealer people is the "thats an old piece of **** you need a new one mentalilty" so that option is out as well.

I was really hoping that with all the views and all the members I would get some experienced advice, but I guess not....

 

[pmsmechanic]

So I just searched "pto slip clutch sale" and came up with numerous sites. Since you don't mention any shaft sizes I can't be more specific but there were numerous sites that came up.


PTO Slip Clutch: Business & Industrial | eBay is one

 

[foggy1111]

I've seen PTO slip clutches offered at TSC. You'd need to measure shaft sizes to get the right fit. The ones I am familiar with are adjustable for slip and will need to be adjusted to your tractor HP and load. Mostly a trial and error method to get it right.....they check it each year to make sure its working right.

 

[Scott65]

I just got done rebuilding an unrecognized slip clutch on a shredder I bought used. I didn't know a thing about them but managed to get it working perfectly thanks to the help of the fine members of tbn. Now, in my search for info about mine, which is a bit different design than "typical", I ran across allot of info about the add-on type clutches such as what's in the link above. I could be very wrong here, but I gathered that the input shaft of the gear box is generally the same as the output pto on the tractor. Meaning it's relatively universal. It's also my understanding that there are 3 basic styles of pto splines, and they are drastically different visually. So if yours looks like the plain ole 6 spline shaft, it is. So it seems simple to confirm, pull your pto shaft and reverse it. If it fits over the gear box, I would think it's universal. Then, make sure the shaft has the same relief cut an inch or so in for the pinch bolt. If all of that works out, I would think you would be safe to order any of the "standard looking" ones on ebay or something. I almost did this for mine but wound up getting away with just replacing clutch disks.

The reason I say ebay, I was in tsc the other day and happened to notice theirs were about double the price. The upside though is that if it doesn't fit you can probably return it.
And again, this is pretty much speculation based on my observations from a repair of a different circumstance. Don't take it as first hand experience please. Maybe someone else will chime in to confirm or deny.

 

[MORRISONSTEEL]

rotary cutters in the 4-7' range should have approx 12,000 in-lb of torque capability for 540 rpm and approx 9,000 in-lb of torque capability for 1000 rpm. Most aftermarket clutch guide books will have this info. An example of a Deere afermarket 540 clutch pack is p/n pm57012000. That is the clutch only, the yoke is then matched to your d-line catagory and the clutch bolted on.