*%#@;'! brush hog.

/ *%#@;'! brush hog. #1  

Shantycoke

Silver Member
Joined
Apr 6, 2007
Messages
180
Location
Appalachian Ohio
Tractor
kubota B7800, Kubota T1570
I hooked up my brush hog to my B7800 today, used it for a couple hours, and now the upper threaded portion of my top link is bent. Seems the connection from the hog to the top link kind of pivots, and the threads were resting on the pivot point. Is the threaded portion removeable so I can run a die on it and try to straighten it and clean up the threads, or would I have to buy a new one? I'm so irritated I could kick a kitten.
 
/ *%#@;'! brush hog. #2  
i had a similar event with my bush hog and b7510. the kubota toplink was available complete only. no parts were available to repair it. the replacement was over $75.

I got one (aftermarket) at tractor supply for about $20. i had to grind down the pivot part the pin goes though to make it fit. it was no big deal just reduced the width.
 
/ *%#@;'! brush hog. #3  
I have bought a number of generic cat 1 toplinks from Agri-Supply
in NC and not only are they way cheaper that OEM, they are often
stouter. I just got one sent to me last week that is for Kubotas,
and it was 12.95, not incl shipping.

But....you should not use a rigid toplink with a RC anyway. A
chain works much better for those times when the toplink gets
rapidly compressed.
 
/ *%#@;'! brush hog. #4  
dfkrug said:
But....you should not use a rigid toplink with a RC anyway. A
chain works much better for those times when the toplink gets
rapidly compressed.

That's contrary to many manufactures safety warnings.


Soundguy
 
/ *%#@;'! brush hog. #5  
I havn't seen your setup.. but IMHO.. sounds like you had your toplink adjusted too long. Sounds like the pivoting section was pivoted all the way back letting the threaded portion get caught in a bind when the rear of the mower wanted to come up a bit.

As the others have said.. many farm stores carry a wide variety of toplinks.

All of the ones I've seen will unscrew completely. Thus.. if you have a thread file.. or die perhaps you can fix it.. depending on if the threads are just flattened. if it really is bent.. i doubt you will get it perfect. It it is a standard thread.. you could buy a piece of allstock and a weld on end.. or cut your old end off and weld it on and call it good... Probably be about half the price of a new toplink.. etc.

Soundguy

Shantycoke said:
I hooked up my brush hog to my B7800 today, used it for a couple hours, and now the upper threaded portion of my top link is bent. Seems the connection from the hog to the top link kind of pivots, and the threads were resting on the pivot point. Is the threaded portion removeable so I can run a die on it and try to straighten it and clean up the threads, or would I have to buy a new one? I'm so irritated I could kick a kitten.
 
/ *%#@;'! brush hog. #6  
Soundguy said:
That's contrary to many manufactures safety warnings.

First I heard of that. Why would it be unsafe to use a non-compressable
toplink instead of a rigid one?

The aftermarket toplinks are so cheap that I buy them and cut the
forged swivel eyes off to make hydraulic toplinks. Often the threaded
rod diameter is larger than OEM, at least for the Kubotas, Deeres, and
Kiotis I have owned. Most often these mechanical toplinks get bent
under compression forces when using a box scraper.
 
/ *%#@;'! brush hog. #7  
Agree you can get inexpensive top links of at least 3 lengths almost anywhere that kind of stuff is sold. Even dealers around here sell them.

Agree, sounds like top link was way too long.

If the Kubota top link is like mine, the threads are mashed at their ends to keep them from unscrewing all the way. I was able to unscrew mine anyway without any real damage to fix it the first time I bent it. The next time, I threw it as far as I could.
 
/ *%#@;'! brush hog. #8  
HomeBrew2 said:
If the Kubota top link is like mine, the threads are mashed at their ends to keep them from unscrewing all the way. I was able to unscrew mine anyway without any real damage to fix it the first time I bent it. The next time, I threw it as far as I could.

I have not seen toplinks with some method of keeping them from
unscrewing all the way. It would be nice though.

If some threads are deliberately mashed on the ends of the threaded
rods, wouldn't that damage the female threads when the toplink
it then assembled?

Mechanical toplinks are such a PITA that it is no wonder that upgrading
to hydraulic should be the first upgrade to a new tractor. Or maybe the
second upgrade after a welded-on FEL bkt hook.
 
/ *%#@;'! brush hog. #9  
dfkrug said:
... If some threads are deliberately mashed on the ends of the threaded rods, wouldn't that damage the female threads when the toplink
it then assembled? ...

Yep, that's the idea ... in this case they just weren't mashed enough to cause any real damage.

dfkrug said:
Mechanical toplinks are such a PITA that it is no wonder that upgrading to hydraulic should be the first upgrade to a new tractor. Or maybe the second upgrade after a welded-on FEL bkt hook ...

They seem pretty simple and easy to me. 'course, I don't need to be messing with mine all the time. No need for bucket hooks here either ... my bucket has a lip on the top of the back of it that works just fine. And to make it a full house, I haven't found a need for a toothbar either ;)
 
/ *%#@;'! brush hog. #10  
HomeBrew2 said:
And to make it a full house, I haven't found a need for a toothbar either ;)

That's an add-on I have never tried. But since I have a BH, I have not
had the need to dig with my FEL bkt.
 
/ *%#@;'! brush hog. #11  
My Woods BB720 says to use the middle or bottom hole for the top link. The only time I seem to flex the system hard is backing off the trailer. Their seems to be enough movement not to put undue pressure on the top link. However I would rather bend my top link than have a really stout one and break my tractor. Mr. Carver at Carver Kubota said things attached to the tractor should be a little less beefy than the tractor which make sense to me.
 
/ *%#@;'! brush hog. #12  
dfkrug said:
Mechanical toplinks are such a PITA that it is no wonder that upgrading
to hydraulic should be the first upgrade to a new tractor. Or maybe the
second upgrade after a welded-on FEL bkt hook.

Just out of curiousity, why do you say that?
I find them quite easy to use...
 
/ *%#@;'! brush hog. #13  
dfkrug said:
Achain works much better for those times when the toplink gets rapidly compressed.
I used to use a top link for everything. After bending the last one three times in one month, I gave up and fixed me a chain. That was about 7 years ago and I still love the chain. It also makes it easier to transport. On one end I leave three or four links hanging out with a hook on the end. When I transport I let the mower down on the ground, hook the hook as far up on the chain as possible, raise it and then away I go. I mow a lot steeper and rougher areas than most on TBN or more than likely I wouldn't need a chain.
 
/ *%#@;'! brush hog. #14  
So long as the chain (or chains) are secured to the sides of the deck of the bush hog, why would this be unsafe? I can see a lot of stress being put on the top link when the bush hogs don't have any flex if the top link connection.

I am not pro at this so I am not sencond guessing someone's experiance, but logic would seem say that the bush hog could be connected to the tractor without any top link at all giving the mower deck the ability to move up and down but not side to side. Obviously when transporting it, you need the link to lift the mower, but why do you need it when cutting?
 
/ *%#@;'! brush hog. #15  
bx24 said:
I am not pro at this so I am not sencond guessing someone's experiance, but logic would seem say that the bush hog could be connected to the tractor without any top link at all giving the mower deck the ability to move up and down but not side to side. Obviously when transporting it, you need the link to lift the mower, but why do you need it when cutting?

You are correct, the toplink is for transporting when not mowing. You
don't really need it when you are mowing. I don't do a lot of mowing,
but I have lifted a RC over some pretty sizeable (2" diameter) weed
stalks, but generally you are not supposed to lift a spinning RC to cut.

I see no safety issue with using a chain of the right size instead of the
toplink.

I said earlier that mechanical toplinks are a PITA as a general statement
(not for mowing where they should not be used at all). I said that
because they need to be constantly adjusted when using a box blade
and adjusted some more every time you hook up a 3pt implement. You
can't always do that from the driver's seat. Hydraulic toplinks are
sooooo much better. You never go back.
 
/ *%#@;'! brush hog. #16  
dfkrug said:
First I heard of that. Why would it be unsafe to use a non-compressable
toplink instead of a rigid one?.

Uh.. a rigid one would be non compressible??? Am I missing something here?


Soundguy
 
/ *%#@;'! brush hog. #17  
A toplink can 'help' prevent a rear turn over. It's an integral part of the 3pt hitch. I have at least one tractor manual that lists it under the safety features section. And another that urges to correctly attach all 3pt linkages for proper and safe operation.

If you have a chain toplink and start to backflip, the chain compresses and does nothing to help stall the back flip.. the rigid toplink at least would provide some resistance..

Many mowers have a flex link installed or some other method like an elongated link attachment hole so that the 3pt mower does have some play in it's toplink attachment. though after that slack is taken out.. it is a rigid connection.

To be fair, On the flip side I have seen some mowers that use chain from the rear of the mower to the a-frame.. thus defeating anything a rigid toplink might help you with.. thus my comment that the practice is contrary to some manufacturers warnings ( obviously not others. )

(( I think my previous post said 'many'.. probably more correct to say 'some'.. in any event, the rest of the comment still stands.. the basic functionability of the 3pt as it was designed and intended to be hitched up can be counted as a safety feature.. hitchint differently defeats the geometry.. thus lessens the effectiveness of that feature... that's all I'm saying.. etc...not telling you what to do on your tractor...))

Soundguy

dfkrug said:
You are correct, the toplink is for transporting when not mowing. You
don't really need it when you are mowing. I don't do a lot of mowing,
but I have lifted a RC over some pretty sizeable (2" diameter) weed
stalks, but generally you are not supposed to lift a spinning RC to cut.

I see no safety issue with using a chain of the right size instead of the
toplink.

I said earlier that mechanical toplinks are a PITA as a general statement
(not for mowing where they should not be used at all). I said that
because they need to be constantly adjusted when using a box blade
and adjusted some more every time you hook up a 3pt implement. You
can't always do that from the driver's seat. Hydraulic toplinks are
sooooo much better. You never go back.
 
/ *%#@;'! brush hog. #18  
One of the main reasons I asked about the chain is my mental comparison to a "pull type" rotary cutter that would essentially be the same thing (without any top support). It would make sense to stop a backwards flip, but I would be more concerned with an operator trying to climb something so steep while bush whacking.
 
/ *%#@;'! brush hog. #19  
DVR said:
i had a similar event with my bush hog and b7510. the kubota toplink was available complete only. no parts were available to repair it. the replacement was over $75.

I got one (aftermarket) at tractor supply for about $20. i had to grind down the pivot part the pin goes though to make it fit. it was no big deal just reduced the width.

Heheheh.... Just did THIS exact same thing the other week. BUT the top link is shorter than the original Kubota link. So, be carefull if your extending it out the whole way.

-Mike Z.
 
/ *%#@;'! brush hog. #20  
Soundguy said:
Uh.. a rigid one would be non compressible??? Am I missing something here?


Soundguy

A chain is a non-compressible top link (can take tension only). So is
a cable. A mechanical toplink will buckle under compression, or the
implement doing the compressing will bend. Seems clear to me.

RCs I have bought come with a pivoting link as the toplink connection.
Although this helps to avoid damage under compression, it can not
react fast enough to a sudden shock.

As for a rigid toplink on a RC preventing a rear rollover, I guess it
could help a bit if you were pulling something at the same time with
your ROPS. But that's a stretch. I suspect 99.999% of rear rollovers
occur using a PHD or pulling something with the rear of the tractor.
 
 
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