Brush Hog slip clutch smoking black smoke

Cathy Liebchen

Active member

Equipment
KUBOTA L3901, MX5800, MULE PRO FX, MULE PRO FXT
We are just hard on things

Bought new tractor and brush hog. Took to new farm to do a back pasture with huge overgrowth (briars, 12 foot tall sweetgums, millions of 3 foot pine volunteers)- it has not been mowed in 5 years. Cut through most of that stuff like butter.

On second day hit some 6 foot tall nasty briars (blackberry and honey vine) and stalled the mower and the slip clutch was smoking black smoke fiercely. Stopped, let it cool down. Did it again a half hour later in huge briars. smoking black smoke fiercely. Stopped, let it cool down.

So we started slowing the speed way down in the briars and it seems to be cutting fine for the days afterwards, we just went really slow in the briar areas. I am guessing the dealer set it up a little loose (we did ask in advance to make sure they would set up the slip clutch).

Some black dust in the PTO housing

MX 5800 with Land Pride RCR 1272

Do we need to do anything?

- do nothing since it is working fine

- Loosen and slip the clutch and then tighten it to specs

- go ahead and have the dealer replace the friction plates- it costs $80 and I would pay that rather than be "that person" to bring back a brand new tractor for what may be user error and want them to do it free

Cathy
 

edritchey

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Jul 19, 2014
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I'd do what you are already doing go a little slower once everything is cut it will be easier to keep after for now on. It's doing what it should just don't over do it and you'll be fine.

Otherwise how do you like the new tractor. :)
 

russell.still.5

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Aug 28, 2017
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I would personally want the clutch a little tighter. The Bush Hog should bog the tractor down before it slips. It’s made to protect the drive line from a sudden impact like a stump of a rock.


Sent from my iPhone using Tapatalk
 

Cathy Liebchen

Active member

Equipment
KUBOTA L3901, MX5800, MULE PRO FX, MULE PRO FXT
here are some pics of the parcel; the back field after mowing, the 1915 farm house before and after boarding it up

One picture is the only one the broker had on the listing, and it looked so bad we almost didn't bother to go look at it except it said "wooded and open areas" in the description and it was the closest thing to our existing property for sale in months that wasn't just billy goat woods
 

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Cathy Liebchen

Active member

Equipment
KUBOTA L3901, MX5800, MULE PRO FX, MULE PRO FXT
I'd do what you are already doing go a little slower once everything is cut it will be easier to keep after for now on. It's doing what it should just don't over do it and you'll be fine.

Otherwise how do you like the new tractor. :)
so far it is everything that people said it would be, a huge step up from a standard L
 

Cathy Liebchen

Active member

Equipment
KUBOTA L3901, MX5800, MULE PRO FX, MULE PRO FXT
I would personally want the clutch a little tighter. The Bush Hog should bog the tractor down before it slips. It’s made to protect the drive line from a sudden impact like a stump of a rock.


Sent from my iPhone using Tapatalk
thanks for this. Glad we didn't just burn it up the first day or so!
 

edritchey

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A bunch of cute little Kubotas
Jul 19, 2014
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Looks nice all fresh cut - Glad to hear you like it so far I was pretty sure you would they are nice all around tractors. If you snug up on those clutch bolts make sure you keep the springs compressed as evenly as you can.
 

SidecarFlip

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One thing to keep in mind with any friction slip clutch is, if the implement sits for any length of time, especially out in the weather, it is a good idea to back the clamping springs and bolts off and break the clutch manually before using it again and re-torquing the clutch to the recommended settings (as listed in your implement owners manual) before using. Reason why is a clutch will get corrosion between the driven plates and drive plates when they sit, especially out in the weather.

I manually break all my clutch packs every season before I use the equipment. Better to be safe that break something.
 

SDT

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multiple and various
Apr 15, 2018
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SE, IN
We are just hard on things

Bought new tractor and brush hog. Took to new farm to do a back pasture with huge overgrowth (briars, 12 foot tall sweetgums, millions of 3 foot pine volunteers)- it has not been mowed in 5 years. Cut through most of that stuff like butter.

On second day hit some 6 foot tall nasty briars (blackberry and honey vine) and stalled the mower and the slip clutch was smoking black smoke fiercely. Stopped, let it cool down. Did it again a half hour later in huge briars. smoking black smoke fiercely. Stopped, let it cool down.

So we started slowing the speed way down in the briars and it seems to be cutting fine for the days afterwards, we just went really slow in the briar areas. I am guessing the dealer set it up a little loose (we did ask in advance to make sure they would set up the slip clutch).

Some black dust in the PTO housing

MX 5800 with Land Pride RCR 1272

Do we need to do anything?

- do nothing since it is working fine

- Loosen and slip the clutch and then tighten it to specs

- go ahead and have the dealer replace the friction plates- it costs $80 and I would pay that rather than be "that person" to bring back a brand new tractor for what may be user error and want them to do it free

Cathy
Too loose.

The slip clutch should not slip when mowing, even at full load.

I would expect that you will need to replace the friction materials considering how much yours has slipped.

SDT
 

D2Cat

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I'd suggest a torque wrench to check each bolt as it is now. Then tight them all the same amount, just a bit more.
 

BAP

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2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Dec 31, 2012
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New Hampshire
The owners manual should tell you how to properly adjust the slip clutch. Usually it is either a torque value on the bolts or a length measurement of the springs when compressed. If you clutch was slipping enough that it was smoking, and did it several times, then you could possibly need new friction discs.
 

D2Cat

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I don't think the disc would need replacement at this point. Those friction disc are plates of material just like a drum brake shoe. They take a lot of abuse. You'll know when they are wore to the place of needing replacement when the material is wore down to near no material.

When you adjust them you can use a soap stick marker to put a mark on the outside of the rotating steel disc (both sides of friction disc) and after using the mower for a minute you can see if the disc slipped.
 

edritchey

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This is good advice and you might want to stock a set or two they are easy to replace and only cost about 10 or 12 bucks a set for that mower. ;)


I don't think the disc would need replacement at this point. Those friction disc are plates of material just like a drum brake shoe. They take a lot of abuse. You'll know when they are wore to the place of needing replacement when the material is wore down to near no material.

When you adjust them you can use a soap stick marker to put a mark on the outside of the rotating steel disc (both sides of friction disc) and after using the mower for a minute you can see if the disc slipped.
 

Nicfin36

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I bought a used rotary cutter for my old John Deere 2030 a couple of years ago. It had a slip clutch. No manual, of course. I loosened the tension nuts before I used it and engaged the PTO a time or two. I marked the discs with a piece of chalk and noticed it had moved.

Although, I have torque wrenches, I had no known value to torque to. What I did was count the number of exposed threads before I loosened the nuts and tightened them back up until I saw the same number exposed as before. I did have it slip a time or two this year in heavy grass, so a touch loose. I cut my field again the other day and tightened the nuts just a tad before I started cutting. No slippage this time, but I think it is adjusted to slip if I did possibly hit something.

I think you definitely need to tighten them some. You shouldn't have slippage cutting briars. I was cutting briars taller than my tractor with no slippage issues.
 

SidecarFlip

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The black 'smoke' is friction disc material just like the 'dust' you get on your car wheels from the brake pads.

I know the slip clutch on my bat wing chopper is working right, when I engage the PTO I can hear it chirp.
 

robertb

New member

Equipment
M7060HD12
Sep 13, 2018
3
0
1
'
I just adjusted my slip clutch. I called the manufacturer and confirmed the spring length prior to adjusting. I then measured each spring with calipers.
 

edritchey

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A bunch of cute little Kubotas
Jul 19, 2014
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Just wondering if you adjusted your slip clutch and if so how is it working now?
 

Cathy Liebchen

Active member

Equipment
KUBOTA L3901, MX5800, MULE PRO FX, MULE PRO FXT
Just wondering if you adjusted your slip clutch and if so how is it working now?
The dealer had set the slip clutch really loose (you could wiggle the bolts and springs), so tightened up it has been cutting great. We picked up replacement pads to change them out at the end of the season.

This last 2 long weekends (we take Thursday-Sundays off to go to the farms) have been tough going since both of these new properties have not been bush hogged in years. Very glad we got the MX5800, it is a beast. The first parcel (the 40 acres) had a big 12 acre field filled with 10-12 foot high sweetgums, briars and smaller volunteer pines. It was last mowed in 2015

The second piece (the former high wall coal mine- 60 acres) has been brutal- multiple fields (probably 20 acres) with big pines up to 4 inches in diameter, 8 foot briars etc. Last mowed probably 6 years ago at least. Last used as a horse and mule business. We chain sawed some of the larger trees, left some in islands and battered the others down with the brush hog set high.

Found the property has 3 abandoned mobile homes buried in the jungle (and several metal storage buildings and a mule pen). Two trailers are very rough and I think the neighbor will haul them out for scrap and scrap the metal buildings (they are junk). He needs to cut at least 20 big pine trees (8" DBH) to get them out. We aren't going to let him scrap the trailers on site and "haul off the leftovers"- too messy.

The larger trailer (1980's 3br, 2ba 12' x 80' singlewide) is "fully furnished" and looks like the person who lived there (who moved out in 2009) just left. He left a big box of old Polaroids but my son was so disappointed to see they are just amateur photos of....mules and wagons

One 4 acre field is a half a mile from the entrance in the back corner just super private back there and loaded with deer.

Tons of industrial trash- we piled up 70 5 gallon plastic drums alone today, and truck parts, pieces of farm implements, 50 gallon drums (2 filled with oil), old tires, oil filters, trailer parts, brake drums, etc. But little household garbage- he used a trash pickup service

Glad that once this is done we can do more normal "grass bush hogging"- This tree clearing has been hard on the brush hog (a couple of dents) and then the tail wheel weld failed on Saturday and the whole wheel assembly fell off the mount, so off to get that fixed tomorrow.
 

edritchey

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Well it sound like the tractors are getting plenty of use good luck with your projects.