Damage brush hogging?

MillerFamilyFarmTrust

New member

Equipment
B7510
Can you through a main bearing by brush hogging thick overgrowth? My brother Vance just told me not to brush hog with our new purchase of a 2005 B7510 as it simply does not have enough horse power to brush hog and if I push the machine it is likely to through a main bearing?
Is this true?
I have used it 2 or 3 times now for brush hogging and the machine bogs down a bit in 2'-4' tall brush but I simply lift the brush hog when it bogs down and keep going but my brother says when it bods down, it is putting a major load on the main bearings and eventually or sooner than later will take out that bearing and that is an expensive fix!

I need a little feedback. Thanks
 

Daren Todd

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Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
May 18, 2014
10,199
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Vilonia, Arkansas
Re: Can you through a main bearing by brush hogging thick overgrowth?

Nope. That statement was false. I just brush hogged the neighbors over grown field. Grass was almost 6ft tall. Tractor is 15hp at the pto.

Just go slow, take your time. Make sure and check the radiator periodically to make sure the screen on the radiator doesn't get blocked with debris and cause it to over heat.

It's like eating a whale. One bite at a time and take it slow and easy.



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RCW

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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
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Chenango County, NY
Re: Can you through a main bearing by brush hogging thick overgrowth?

Daren is a good guy! As he said, go slow to avoid bogging it down too much. Eat the elephant one bite at a time......

For your information, here are the specs for your B7510:

http://www.tractordata.com/farm-tractors/001/8/6/1860-kubota-b7510.html

Daren's is an "L" series, but similar in HP, etc. to yours.
 

torch

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B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
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Muskoka, Ont.
Re: Can you through a main bearing by brush hogging thick overgrowth?

Tractors are designed to do work. Bearings, lubrication and so forth are engineered to handle what the engine can generate. As long as you don't add a turbo or overspeed the engine, it should handle loads up to and including a stall load. Personally, I'd be more worried about shock loads to the PTO gears and shafts than the engine bearings. So, stay within your HP requirements and you will be fine.

One rule of thumb for a brush hog is 5hp per foot of width, but that is obviously dependent on how hard you are pushing it and how thick the brush is. TractorData.com suggests you have 17hp available at the PTO, so I would think you could get away with a 4' brush hog if you take it easy, but that a 5' brush hog might be a bit much for that machine.

That said, ultimately the maximum HP / shock load you can apply is limited by the PTO clutch or shear pin. You can put a 7' brush hog on there if you adjust the slip clutch low enough or install a suitably sized shear bolt (eg: turn a groove in the bolt to reduce it's cross-section at the shear line). You would find it frustrating and have to go very slow, and I wouldn't recommend it, but you wouldn't damage your tractor.
 

beex

Member
May 21, 2019
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18
on my bx
It is bad to bog a diesel down though. If it’s blowing black smoke it’s bogged too much, back off ground speed and let it recover. It’s better for it to run WOT at PTO speed, than to bog it. When black smoke is coming out, bad things are happening, it’s not burning all the fuel, gunking up the engine, and the torque load is high, firing is not smooth.


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lugbolt

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Equipment
ZG127S-54
Oct 15, 2015
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Mid, South, USA
black smoke means it's working.

It's not carboning anything up. Well maybe the muffler and the atmosphere. Internally, no.

BUT a diesel engine runs it's hottest when run at max torque, which is usually around 1800-2200 RPM, when under a load. If you're bogging the motor down and it's staying consistently around peak torque, the little engine is making some heat....and it has to get rid of it. This is where the cooling system is crucial! Keep the radiator (and screen) clean!! Also the air filter needs to be kept clean; as the incoming air is one of the major cooling components of a diesel engine. I have seen a plugged air filter and continual heavy load combined with partially restricted radiator screen cause "holed" pistons. Not common, though.

Main bearing? About the only time an engine main bearing is going to fail is when it's starved for oil.
 

Bulldog

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M 9000 DTC, L 3000 DT
Mar 30, 2010
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Rocky Face, Georgia
Use quality lubricants and filters then put it to work. Run it at the correct rpm so it can perform as it should and you'll be fine.
 

Magicman

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M4900 Utility Special 4WD e/w FEL & 1530 John Deere "Traveling Man"
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knotholesawmill.com
Be certain that your blades are sharp. Also the front needs to be lower than the rear to keep the BushHog from having to deal with cutting the grass more than once. (The above is from my BushHog operator's manual.)