New guy here...Some brushhog questions

[ericinok]

I have recently purchased a Kubota L3010 to keep up my 20 acres that I bought last year. I had an old '53 Ford Jubilee that I tried to use to brushhog, but it died quickly. The 5' Ag-King cutter is still in fairly good condition, so I hooked it up this weekend to the Orange Machine and started cutting.

After getting hooked up, I noticed the link arms (lift arms, whatever you call the 2 arms on either side and below the PTO) will actually rub the tires when turning or on a slope. This can't be good for the tires, the mower or me. From the wear patterns on the tires, it appears the previous owner experienced this also, because the inside of the treads are a little worn where the arms are positioned. I checked out the Jubilee, and it had the PTO and arms that stuck out much further behind the tractor, whereas the Kubota has all it's junk right below the seat. Any idea on this one? I thought of extending the arms out further, but I'm not sure I'm comfortable extending out the jackshaft more than it is right now (which is much more than when on the Ford).

Speaking of the jackshaft - when I engaged the PTO, the bolt that holds the jackshaft to the brushhog immediately snapped. I then put another bolt in, and it did it again. Mind you, I had the engine at a pretty low RPM both times. I then went to the hardware store and bought the strongest bolts and nuts they had and put one on there. It worked until I started it back up again after lunch. I guess the morale to my story is "never stop for lunch". I know that's a lot of resistance when the PTO is engaged, but it doesn't seem like it should be snapping bolts like that. I had the deck raised and the RPM's low, like I said. Could there be something on the cutter that needs work? It's pretty old, and probably needs a little love.

There are my first two issues. I appreciate any help I can get. You are welcome to make fun of my lack of knowledge, and call me any name you wish, as long as you also give me a good solution.

 

[beersngars]

Hi there, I know exacly what you mean about the lower arm to tire clearence. I just had my new L3400HST delivered yesterday and on mine there are stabilizer bars with turn buckles on the outside if the lower arms. I asked the salesman and he said they were a good idea with some implements but not necesary on others. My quess is most of the smaller tractors will need some type of brace as most are narrow.

As to the bolts breaking, there must be something binding or seized. Better figure it out as stonger bolts aren't the answer.

 

[atgreene]

The lift arms should have a turn buckle or pin type arm stay that prevents either arm from moving too far near the tires as well as prevent the implement from swinging back and forth. With a rotary mower, this is important on a hillside.

There should be a large hole in the lift arm and a place under the axle of the tractor for this turnbuckle to attach.

As far as your bolt in the pto shaft (the shaft is called a power take off shaft) it should be a grade 3 or 5 and is designed to break if you encounter an immovable object (rock, stump etc...) and prevent the pto shaft or gear box from disinigrating. Do you have a two stage clutch? If you step on the clutch partway, does the tractor stop moving but the pto continue? I'm not familair with Kubota 3010, but if this is out of adjustment I suppose you could be snapping the pto shaft. Do you also have a slip clutch? If not, you can buy a slide-on slip clutch that will go on your pto shaft on the rear of the tractor.

How are you engaging the pto, do you ease out on the clutch or just throw the lever to engage it? A quick jerk can, but shouldn't, snap the shear pin/bolt. Can you turn the pto by hand and have the rotary mower blades turn? You should be able to free-spin the shaft and make the blades turn, if not, your gearbox on the rotary may be bound. Check the fluid in the gearbox while you're at it, just to be safe. The gearbox lower seal just above the blades is notorious for leaking and the box then runs without oil, very bad.

Here's a link on one place you can buy a slip clutch, they are available at most tractor supply places and maybe even here at one of the links.
PTO Slip Clutch

 

[travis potter]

I can't help on the arms but on the bolt my understanding is it should be a soft bolt to protect the PTO in the tractor if it is a hard bolt and you hit something it will not break and ruin the pto. Try turning the gearbox by hand it should turn freeley with only the weight of the blades causing resistance if not you could have picked up some wire under the bh (last week for me) If the lower seal is leaking {mine} fill the gear box with heavy grease [several years for me]. Hope this helps.

 

[ericinok]

I was able to turn the pto and make the blades turn by hand, so I don't believe that anything is unmovable. Once I put the big bolt in, I was able to enagage it and actually got about 5 acres mowed before lunch.

Then, when I started it up again is when the bolt came out. It did not break like the smaller ones, it just bent and the nut came lose.

My L3010 has a HST. I just engaged the pto at a slow rpm with the deck raised. I eased it over, so it would not start rapidly, but it still would break the bolt right away. I'm wondering now if I should maybe push in the clutch and have it start up even slower. The tractor did not come with an owners manual, the dealer is supposed to have me one this week.

Sounds like a stronger bolt is not the answer. I'll oil up the gearbox on the mower and try the clutch. Thanks.

 

[IslandTractor]

You say you are new so I will ask...are you sure it is the right size bolt? The bolt should fill the shear bolt hole completely. 1/2 inch is usually what a 4 or 5 ft cutter would use.

We've all broken shear bolts but your initial experiences were odd in that you were breaking so many. The last time you say the bolt was bent....that is real hard to do if it is the right size as there is no room for it to bend. It breaks rather than bends. Maybe it bent as it was coming out as you mentioned that the bolt had fallen off. (use a lock washer by the way)

 

[Grrrr]

One other thing about the bolts...

Have you tried buying any bolts labelled as shear bolts. The last time I wanted some there were about ten different hardnesses in the shop and I wasn't sure which one was best. I ended up with a medium hardness one as that is what the guy suggested.

I don't think normal bolts are quite the same as shear bolts.

 

[jbrumberg]

ericinok:

No one should laugh at you here at TBN. We all have had our "learning curves"; some more accelerated than others ! All of the previous posters offer good suggestions. I would look at the lower seal for leakage and see if wire and/or bailing string is binding up the lower shaft. You did not mention any problems with vibration, but make sure that the cutting blades are clear of debris and free swinging on the blade pan/stump jumper plate. I would also check the blades for cracks, knicks, and gouges. It does not take a lot of missing metal to throw a rotary cutter out of balance. Just some additional hints regarding rotary cutter use. Jay

 

[excel25]

on my 3010HST I have to use the clutch and let it out slow Works great!!

 

[MarkV]

As far as tire clearance goes. Can the pins be remounted to point to the inside of the bush hog frame? I did that for a small tractor that did not have enough spread on the lift arms. The tires on that tractor can be set for a wider stance and may be at their narrowest setting now.

MarkV

 

[RobT]

Eric:

I was a brand new "newbie" last year and this forum has really helped me. I'm still much of a newbie, but I've spent about 100 hours bush hogging so far and have found that the shear bolt breaks if you encounter dirt, big rocks, etc.

Also, I make sure I grease up the PTO shaft connections EVERY time I go out. It takes a few extra minutes, but I think it helps (I was breaking many bolts at the beginning).

When I start out, here's my routine:

1. Raise the cutter the deck off the ground several inches cutting height
2. Engage the PTO at 550---never 1000
3. Set the tractor RPMs down all the way (or as lows as I can get them)
4. Ease off the clutch to allow PTO to start and for blade to start moving
5. Slowly increase tractor RPMs
6. Lower deck to cutting height

RobT

 

[Alan L.]

My B2710 has stabilizer bars so that the upper links can be more or less frozen in place so there is no side to side movement thus the arms never get into the tires. Maybe you have a similar situation but if the bars are just too wide on both sides I don't know what the solution would be.

 

[madpogue]

The spec for the shear pin on my KK 5-foot 40-hp mower is a simple 3/8" x 3.5", grade 2 (the softest) bolt and nut. If you're breaking shear pins immediately on engagement, with the engine at idle, something's not right. With the mower deck on blocks/stands, or the whole mower on level enough ground to have the blade free of any obstruction, can you turn the PTO shaft by hand and turn the blade? If not, your gearbox oil is probably very old, or the main vertical shaft going thru the deck needs to be lubed, or something.

In short, that pin sheared because it's supposed to. It's intentionally the weakest thing; it sacrifices itself so that a restriction or obstruction doesn't instead damage or break some other part (chew up a gear in the gearbox, twist the PTO shaft, etc.). So don't leave that harder grade bolt in there.

Now, it's possible that something with the mower was "stuck", and putting in the harder shear pin got the PTO to drive it hard enough to get it "unstuck". But to me, that means it's time to give the mower's mechanicals a once-over.

 

[Spiveyman]

I was a brand new "newbie" last year...

I'm also a newbie and have a question about your post, but first, ericinok, hopefully the folks here at TBN won't be laughing at you, maybe laughing with you as we've been there as well. I bought a farm last year, but just got my first tractor last month. I tried to get a buddy to show me how to hook up a rotary cutter and get 'er going, but he didn't have time. Asked my papaw but he hurt his foot and couldn't, so I just figured I'd give it a try. After some frustration at trying to hook it up, (my 3ph is Cat2, cutter is Cat1, and I wasn't too good at lining her up), I figured out the PTO shaft and was ready. The next part was the tricky part for me. I saw 540 and 1000 on the RPM gage, so I revved her up to 540 and engaged the PTO. My first experience with a sheer bolt was more like shrapnel! Luckily the sheer bolt did it's job and saved the tractor and cutter from another newbie mistake. Later I read the tractor manual (imagine that ) and found out that my tractor has a mid point in the PTO lever travel for getting the implement up to speed before fully engaging.

When I start out, here's my routine:

1. Raise the cutter the deck off the ground several inches cutting height
2. Engage the PTO at 550---never 1000
3. Set the tractor RPMs down all the way (or as lows as I can get them)
4. Ease off the clutch to allow PTO to start and for blade to start moving
5. Slowly increase tractor RPMs
6. Lower deck to cutting height

Here's the part that I'm curious about, step #2. engage PTO at 550. My RPM gage show's an RPM position for 540 and 1000:



Do you mean to get the RPM up to the 540 spot and then slowly engage the PTO? Step #3 has the RPM down low and #5 says to bring the RPM up. Is step 2 a parenthetical comment or is there something you are doing there?

Sorry if that's a goofy question, but I'd rather look silly here than to be getting stitches because I didn't ask the question. By the way, a pocket full of sheer bolts is now standard when I mow.

 

[Grrrr]

When I start out, here's my routine:
​

1. Raise the cutter the deck off the ground several inches cutting height
2. Engage the PTO at 550---never 1000
3. Set the tractor RPMs down all the way (or as lows as I can get them)
4. Ease off the clutch to allow PTO to start and for blade to start moving
5. Slowly increase tractor RPMs
6. Lower deck to cutting height

I'm also a newbie and have a question about your post, but first, ericinok, hopefully the folks here at TBN won't be laughing at you, maybe laughing with you as we've been there as well. I bought a farm last year, but just got my first tractor last month. I tried to get a buddy to show me how to hook up a rotary cutter and get 'er going, but he didn't have time. Asked my papaw but he hurt his foot and couldn't, so I just figured I'd give it a try. After some frustration at trying to hook it up, (my 3ph is Cat2, cutter is Cat1, and I wasn't too good at lining her up), I figured out the PTO shaft and was ready. The next part was the tricky part for me. I saw 540 and 1000 on the RPM gage, so I revved her up to 540 and engaged the PTO. My first experience with a sheer bolt was more like shrapnel! Luckily the sheer bolt did it's job and saved the tractor and cutter from another newbie mistake. Later I read the tractor manual (imagine that ) and found out that my tractor has a mid point in the PTO lever travel for getting the implement up to speed before fully engaging.




Here's the part that I'm curious about, step #2. engage PTO at 550. My RPM gage show's an RPM position for 540 and 1000:

View attachment 84411

Do you mean to get the RPM up to the 540 spot and then slowly engage the PTO? Step #3 has the RPM down low and #5 says to bring the RPM up. Is step 2 a parenthetical comment or is there something you are doing there?

Sorry if that's a goofy question, but I'd rather look silly here than to be getting stitches because I didn't ask the question. By the way, a pocket full of sheer bolts is now standard when I mow.

First, I think that 540 RPM is the standard PTO speed, never 550 RPM.

I think he means that you want to lower your revs down to a fast idle and engage the pto slowly as you said you do.

Then, once the cutter is spinning happilly, crank the revs up to 540 RPM on the tacho.

I think you are doing it right allready.

The difference with what Rob said is that his tractor has a lever that engages the pto. But you then have to let out the clutch for it to start up.

 

[sandman2234]

Just to make sure everyone is clear on this, the speeds noted for pto on your tachometer are for the engine rpm to make the pto spin at that particular speed. Or in other words, the speed the engine has to turn in order for the pto to be turning the rated speed.(540/1000, etc)
Those are NOT engagement speeds and are subject to tear something up if your not extremely lucky. Engage the pto at the slowest possible speed, lowest possible load, and increase speed/load after it is engaged.
Just wanted to make this clear,
David from jax

 

[ericinok]

ONE PROBLEM SOLVED!!!

I read all the replies here, and also started thinking about it. Even with a HST tractor, it would still make sense to use the clutch and ease it out when engaging the pto. Like I said earlier, I am waiting on my manual, but was too excited to get going. Anyway, I tried getting it going and easing out the clutch at a low rpm, and it worked like a charm. Several times. Now, I'll go buy some shear bolts and take out that hard one (that didn't sound right, did it?).
Thanks for all the help on that one.

As for my other problem, I have still not conquered it yet. This weekend I'll get under there and see if I can reverse the arms or if there is a pin I can set to keep the arms still. However, it seems like you would not want them to be entirely still, and I only have about 3" of clearance right now on both arms before they hit the tire?

If I can't figure it out, I'll take a picture and post it here, so you guys can see exactly what I'm talking about.

Another question - what kind/type of oil do you put in the gearbox? I'm sure this hasn't been done in many years.

 

[Spiveyman]

First, I think that 540 RPM is the standard PTO speed, never 550 RPM.

I think he means that you want to lower your revs down to a fast idle and engage the pto slowly as you said you do.

Then, once the cutter is spinning happilly, crank the revs up to 540 RPM on the tacho.

I think you are doing it right allready.

The difference with what Rob said is that his tractor has a lever that engages the pto. But you then have to let out the clutch for it to start up.

Cool thanks! At least that's something I'm doing right. 1 down, 14,756 to go.

Just to make sure everyone is clear on this, the speeds noted for pto on your tachometer are for the engine rpm to make the pto spin at that particular speed. Or in other words, the speed the engine has to turn in order for the pto to be turning the rated speed.(540/1000, etc)
Those are NOT engagement speeds and are subject to tear something up if your not extremely lucky. Engage the pto at the slowest possible speed, lowest possible load, and increase speed/load after it is engaged.
Just wanted to make this clear

You know what they say, God watches over fools and little children. I think I've squeaked under that first category more than once. Luckily that sheer bolt just snapped clean so I didn't tear something up.

... see if I can reverse the arms or if there is a pin I can set to keep the arms still. However, it seems like you would not want them to be entirely still...

Yep, you have to be careful there. I realize we likely have very different systems (Blue Vs. Orange), but... do you have telescopic stabilizers? Does your attach point have upper and lower holes? On my tractor you can let the stabilizers allow some sway, and attach the stabilizers to the upper holes and this will limit the sway, or you can use a solid position and eliminate the sway but you have to use the lower positions, there are cautions with either way... you know what... I'll just scan that page from my manual. It will do a better job with pics than I can do with words. Maybe one of you Orange guys could do that to hold ericinok over until he get's his manual.

 

[ericinok]

I appreciate the help, Spiveyman. Our set-ups look pretty much the same, so I'll pretend I have a Ford until I get my manual.

Is my monitor blurry, or does your dashboard show 4000 hours? Wow, that's what I call getting your money's worth out of a machine. I was feeling bad about putting 10 hours on mine already, kicking it up to 613 hours.

Thanks again.

 

[JoeinTX]

Really nothing to do with the poster's issues as you're simply feeling your way out and rightly so, but, I've never sheared a shear pin in my life.


Shredding.......digging post holes......spreading......etc......never. I've used a variety implements and units ranging from the 8N Ford to the 120hp MF to the old Corsicana 5ft shredder and 10' Mohawk cutter.....never a blip. Digging through our dry hard clay and rock down to 3-4' or using the 5' Howse to pulverize brush and roots and 2" overgrown growth......never a shear pin replaced in 20 years.


I'm envious of the process.............what are you guys doing doing to split pins at such a regular rate??? I need to know.