Rotary Cutter Bush Hog Troubleshooting - Woods? Slip Clutch Issues with Kubota M60

[Brian62]

Afternoon,

I recently acquired a bush hog (potentially a Woods model, unsure) and am experiencing issues with repeated sheer pin failures when using it with my Kubota M6040 tractor.

Initially, the sheer pin would break quickly upon engagement. I then loosened and cleaned the slip clutch, and recalibrated the springs. This improved things slightly, but the sheer pin still breaks when encountering rougher patches.

I have two main questions:

1. Identification: Is there a way to positively identify if this is a Woods bush hog?
2. Compatibility: Could the PTO shaft and/or slip clutch be undersized for this bush hog and my M6040 tractor?

Any advice or insights would be greatly appreciated, as I'd like to get this bush hog working this season as an alternative to my flail mower in certain areas.

Thanks in advance for your help.

 

[nybirdman]

Don't know why it would have both a shear pin and a slip clutch.If the clutch is working go with a grade 8 shear bolt.
Looks like a lite duty model.

 

[Brian62]

Yeah, I don't really don't know much about this. My neighbor gave it to me when he was moving out of his house after his divorce and it's pretty much set in my yard for about a year or so. I saw somebody on Facebook market page that has one almost exactly like it and they label it a Woods so that's what I'm thinking it is.

I thought about using a grade 8 sheer bolt, but I was afraid that it could do some damage to the gearbox if I hit something too hard. But I think I might give this a try as I'm getting ready to do some briar cleanup in the coming week.

 

[Lineman North Florida]

As long as you have backed the nuts off of the slip clutch a little ways and then engaged the PTO several times to make sure the plates are broke free and slipping and then re-tightened them to spec then there should be no reason to not upgrade to a grade 8 bolt on the drive line and put it to work.

 

[ssgp2]

Sounds like the clutch is frozen or it has the wrong bolts in it. The bolts should have extra threads showing past the nuts, and looking at the picture, doesn't seem to have any or they are loosened all the way already and it is indeed frozen (rusted). Proper adjustment can be found online and most slip clutches are real close on adjustment specs and slip procedure that should be done at the beginning of mowing season .
Some units use a regular bolt while others use tapered bolts without a head to secure the clutch assembly to the input shaft. Also, a sheer bolt would be in the grade 0 to 3 range. Grade 8 isn't considered a sheer bolt.

 

[geneP]

There is a brush cutter on my local Craigslist that is built exactly like yours and the seller says it is a Woods.

https://jackson.craigslist.org/grd/d/bolton-bush-hog/7835491401.html

 

[Brian62]

As long as you have backed the nuts off of the slip clutch a little ways and then engaged the PTO several times to make sure the plates are broke free and slipping and then re-tightened them to spec then there should be no reason to not upgrade to a grade 8 bolt on the drive line and put it to work.

Thanks.

 

[Brian62]

There is a brush cutter on my local Craigslist that is built exactly like yours and the seller says it is a Woods.

https://jackson.craigslist.org/grd/d/bolton-bush-hog/7835491401.html

Mine is a 6 foot, but looks exactly like the one you linked to.

 

[Brian62]

Sounds like the clutch is frozen or it has the wrong bolts in it. The bolts should have extra threads showing past the nuts, and looking at the picture, doesn't seem to have any or they are loosened all the way already and it is indeed frozen (rusted). Proper adjustment can be found online and most slip clutches are real close on adjustment specs and slip procedure that should be done at the beginning of mowing season .
Some units use a regular bolt while others use tapered bolts without a head to secure the clutch assembly to the input shaft. Also, a sheer bolt would be in the grade 0 to 3 range. Grade 8 isn't considered a sheer bolt.

thanks

 

[gstrom99]

Like others said, it shouldn't have BOTH safety devices. There's lots of info "out there" on slip-clutch adjustment. I just bought a new rototiller with one, and I feel I need to check it's function/adjustment before I use it. The separate PTO shaft manual it came with doesn't really address that.

Here's one link:

How to Properly Adjust & Maintain Your PTO Slip Clutch | IronCraft | Tractor & Skid Steer Attachments

INTRO: A slip clutch is a mechanical device used in PTO machines to protect components from damage caused by excessive torque or overload. The slip clutch m ...

www.ironcraftusa.com