Tractor Size v Implement Size

[buickal]

With regard to tractor size, I know that implements cannot be too big for a tractor. However, what about using implements where the tractor is actually capable of handling larger instruments. For example, using a 6 foot bush hog when the tractor is large and strong enough to handle a 12 foot bush hog. I know my HD Silverado can pull up to 15,000lbs but I can pull as little as I want without issue also. The only danger I could think of is potential damage to an implement but if a mower is a 540rpm and the tractor does that then what’s the downside? Is this a situation where bigger is ok up to a point and if so, what’s the point where it’s not ok?

 

[JohnRowehl]

Two thoughts:
Fuel efficiency may be reduced. If you are pulling something like a plow or disk, you can gear-up and throttle down to compensate.

Might be tempted to go faster than you should. Watch that with something like a disk harrow so you don’t throw soil too far and create ridges.

 

[560Dennis]

Soil type is what I would consider For tillage implements.

 

[BarnyardEngineering]

There's a saying I've read: You can do small jobs with a big tractor but you can't do big jobs with a small tractor.

It's all about the operator. If you're a "bull in a china shop" type where you just have to "send it" because you have the power, you're going to wreck stuff. Operate the equipment at the same speed as you would with the "right size" tractor.

Your bush hog should have a slip clutch and/or shear pin to protect it. If you are breaking shear pins or slipping the (properly adjusted) clutch, you need to re-think what you're doing. Either you're going too fast or the brush is too large/heavy for the machine. Resist the temptation to use a larger/harder shear pin or to tighten the clutch down. You will wreck something with the larger tractor. You'd probably wreck something with the "right size" tractor too, to be fair.

 

[J Hamilton]

For operating a PTO driven implement, you would not want to greatly exceed the input horsepower to the gearbox. For example, I have a 130 HP tractor that easily pulls a 15 foot rotary mower. While it could be hooked to my 5 foot mower, I would not do that because the 5 foot is only rated for about 40 HP input. But, say I wanted to put an 80 HP tractor on the 5 foot mower, it would probably be fine as long as you were easy with it and understand that you are overpowering it. With all that said, I have seen some people operating a 15 foot mower with an MX305 CaseIH, to me that is way to excessive, but that's not my equipment either.

 

[Bob Bancroft]

With regard to tractor size, I know that implements cannot be too big for a tractor. However, what about using implements where the tractor is actually capable of handling larger instruments. For example, using a 6 foot bush hog when the tractor is large and strong enough to handle a 12 foot bush hog. I know my HD Silverado can pull up to 15,000lbs but I can pull as little as I want without issue also. The only danger I could think of is potential damage to an implement but if a mower is a 540rpm and the tractor does that then what’s the downside? Is this a situation where bigger is ok up to a point and if so, what’s the point where it’s not ok?

It all depends.............
When I bought a 15 foot bat wing I got a 540 RPM version on purpose. I didn't necessarily have the correct tractor to run it at the time, but hoped I would someday, and happily, that has happened. At the time, I ran it with a 200+ HP tractor. I had to adapt the large 1000 RPM shaft down to 540, and ran the engine slow enough to get 540 RPM. It worked fine.
I have since also acquired a three point hitch boom mower. It likewise is 540, and run with a 200+HP tractor. I did that for stability.
What's handy about these tractors is they tell you right on the dash what your PTO speed is, so no guessing is involved.

 

[RJKeith]

There's a saying I've read: You can do small jobs with a big tractor but you can't do big jobs with a small tractor.

It's all about the operator. If you're a "bull in a china shop" type where you just have to "send it" because you have the power, you're going to wreck stuff. Operate the equipment at the same speed as you would with the "right size" tractor.

Your bush hog should have a slip clutch and/or shear pin to protect it. If you are breaking shear pins or slipping the (properly adjusted) clutch, you need to re-think what you're doing. Either you're going too fast or the brush is too large/heavy for the machine. Resist the temptation to use a larger/harder shear pin or to tighten the clutch down. You will wreck something with the larger tractor. You'd probably wreck something with the "right size" tractor too, to be fair.

Just to add, that shear pin is their to protect the equipment and is sized/speced to do so. They are easy, quick, and cheap to replace, especially compared to a gear box or drive shaft.

 

[jwal10]

With the older tractors I run smaller equipment. If 4 plow tractor, I run 3 now. Less stress on the older machinery too. 3020 was a 4 plow tractor, I run 3. I also ran 1 size smaller with my 4020 and ran faster, like the 4000 was designed for. I sized my equipment for 5th gear with a P.S. My ground was sandy river bottom ground. I pulled a 5-18" plow with the 4240 JD's, that was all I could pull with a 4430. Actually the 4430 came with 5-16's, no way it would pull 6-16's. I had a 6-16" on-land plow for the 4630 and it was a load. I also found after radial tires came out, I didn't need to weight the 4240's down with liquid ballast. I just ran 2 sets of weights. My P.S. 4240's had hfwa. Some tractors are higher HP. for their weight and tire size. My 454 IH is 45 hp but I can only pull 2-16" 3 pt plow. My H was nearly 1/2 the HP but it would pull a 2-16" tag plow, the 454 will not pull the tag plow, not enough traction. But the 454 will pull a 2-16" 3pt plow at nearly double the speed. I ran an 8' drawbar mount rotary mower with the H but only a 6' 3pt mower with the 454 because 8' is too heavy to lift....James

 

[timcasbolt]

I remember watching a neighbor many years ago. He was always struggling for lack of time and poor preparation. Had a Allis 180 and broke his 4 bottom plow, so he borrowed a 2 bottom from a neighbor and was trying to cover the same ground in the same time. That poor plow never saw dirt again after he got done with it.

I used to mow with a 5 ft bush hog and a Farmall M. Kind of overkill, but I never tried to push it and never had a problem.

 

[620 John]

I know some guys will run bigger equipment on smaller implements to save wear and tear on the tractor. They don't push anything hard, just run the implement the same way as it would with a smaller tractor. Bigger tractors are obviously designed for heavier loads. But when used with smaller implements the tractor lasts longer. Fuel efficiency as mentioned also plays a factor.

 

[buickal]

Excellent insight and comments by all who have responded. Very helpful and thanks to everyone for responding.

 

[Destroked 450]

I don’t have a big tractor so it’s not a real issue for me, however I do try to size the tractors I have to the properly sized equipment
I know some don’t own a small tractor and have to use what they have no matter how mismatched, as long as they treat it as a small piece of equipment it’ll be ok
I did get a good laugh one day when I saw someone raking hay pulling a NH 256 bar rake with a 1486 IH

 

[Fixingfarmer]

One other thing I don’t think anyone has mentioned is hydraulic flow. Hook a 3 or 400 hp modern tractor with a modern high flow pump the old cylinders on a disk will let the oil out reel quick or even bend a rod. We have a 40 year old sprayer that we put an annual fleet farm cylinder on because someone doesn’t believe me that the flow rate can be at 10 percent and be fine. Same with pump on the borrowed old nitrogen bar. Start low creep up. Turtle to start never rabbit.

Other than that and compaction as long as you keep the speed down it’s generally bigger is better.