What is the most stable tractor for hilly terrain?

[Gary Fowler]

All current CUT's are built basically the same so one is not going to be any more stable than another given the same tire spacing and setup. If you absolutely have to mow sideways on hillside, look for the specialty tractors similar to the Power Trac, Steiner etc. They will cost more for implements and the tractor is high dollar but they can mow much steeper than any traditional tractor.

The easier solution is to not mow or travel sideways on a slope and only go straight up and straight down. Never turn on a slope either. Then a regular tractor of your favorite brand will do the job safely.

 

[CobyRupert]

Thanks for all the suggestions,

I was researching and I found that the Massey Ferguson 2600H series has lower center of gravity and I'll probably go see one in the next week. I called the dealer and they also recommend filled tires, they also suggested R4 tires, he said that they are smaller diameter so they lower the tractor.

So I think that I'll go see them and I'll let you know what I decided.

Thanks again for your help,
Paul

Yes R4's are probably a bit smaller, technically, if measured on pavement, but I don't think by much, and probably very little if the lug is sinking into the ground, versus a R4 which may have a greater tendency to float on the surface.
One question is how important is the inch or so you lower the C.O.G. with R4's compared to how often do tractors roll because the tire slides, then catches? IMHO, R4's are more likely to slide. On a hillside I'd want R1's.

 

[MossRoad]

Check out the Case IH JX series straddle tractors

JX Straddle Tractors | Case IH

They're called "straddle" because you sit lower on the tractor with your legs straddling the transmission. My 1964 MF135 diesel is a classic straddle tractor with a low center of gravity for maximum stability.

View attachment 545994View attachment 545995

My 135 has been modified to squat very low for work in orchards. The rear rims are 16" dia instead of 28-32", the rear wheels are 18" wide (like those used on a combine or a bankout truck) and the front axle spindles have been shortened to keep the tractor level.

Good luck

My late 70's IH2500b was like that. The tranny tunnel is between your legs, so you sit down a good foot lower than a normal machine. However, it was no match for my little Power Trac PT425, which I can take on 25 degree slopes and do donuts (slow donuts) on the side of the hill.

 

[Egon]

Check out tractors used in the European alpine regions. There are some designed for working steep slopes.

 

[Fallon]

Tractors will generally tip a,lot harder than you think they will IF YOU DONT LIFT AN IMPLIMENT/LOADER. I got my 60" track L3200 into a few precarious positions while mowing. I was inching along mowing a ditch side hill way past my pucker meter going off. I left it in 2wd intentionally & slowly inched along heeled over at I'm guessing was at least 35 degrees. I knew it was time to abort when I stopped moving forward. I looked over & my high side tire was still spinning. I backed out in 4wd & carried on avoiding the rest of the steep part of the ditch. I'm sure it would have been much uglier if I didn't have the loader really low or had tried lifting the flail mower when I backed out.

As others have already said, lots of ballast as low as possible & go as wide as possible for max stability.

 

[MossRoad]

Someone's going to have to do the science on that, because if you'd lift a 3pt implement like a mower off the ground, all of the weight of the implement would be transferred to the tractor wheels. Your traction would increase dramatically, and, of course, your center of gravity would change.

 

[CobyRupert]

Someone's going to have to do the science on that, because if you'd lift a 3pt implement like a mower off the ground, all of the weight of the implement would be transferred to the tractor wheels. Your traction would increase dramatically, and, of course, your center of gravity would change.

Yes. If you add weight below the center of gravity, you lower the center of gravity.

 

[MossRoad]

Yes. If you add weight below the center of gravity, you lower the center of gravity.

You are correct, however, I was thinking more along the lines of shifting the center of gravity left/right and fore/aft.

My little Power Trac PT425 is articulated. We Power Trac owners get a real good sense of how the center of gravity can change quickly. For example, I can turn the steering wheel all the way to one side (doesn't matter which side), lift the bucket a few inches off the ground, and start tossing landscape blocks into the bucket until it tips forward onto the bucket, raising the rear wheels off the ground. If I reach in and grab the steering wheel, and start turning it towards straight, the rear wheels will come back down to the ground, and the bucket will lift back off the ground.

This is because the machine bends in the middle. By turning the steering wheel, you are bringing the front and rear halves of the machine closer together, making the machine shorter, and changing the center of gravity.

Another interesting thing about these machines is that since all attachments are on the front end loader lift arms, you can easily mess with the center of gravity and traction. So let's say I'm pushing up a steep hill with the brush cutter or finish mower and I start to lose traction, making the wheels spin. The brush cutter and mower are riding on their own wheels, so the machine is just pushing them, not really carrying them. If I pull the joystick out of float, and back just enough the get the mower wheels 1/8" off the ground (the distance isn't important, only that the mower wheels aren't touching the ground), that instantly transfers all of the weight of the mower deck and part of the FEL arms to the front wheels of the machine, I gain weight over the front wheels, which = traction, the tires stop spinning and up the hill I go because of the traction gain on the front tires. While I lose some traction on the rears, I want it on the fronts to climb the hill.

So you can see how that would work on a tractor pulling a brush hog on a 3pt hitch as well. If the brush hog has a rear caster wheel, about half of the weight of the brush hog is on the 3pt arms and half the weight is on the caster wheel if the 3pt is in float. By taking the 3pt out of float, and lifting the brush hog just enough to get the caster wheel off the gound, all of the weigh of the brush hog will be added to the rear tires, increasing traction. However, that will also decrease the weight on the front tires a bit, and decrease steering traction. It'll also change the center of gravity of the machine quite a bit.

It would be neat to put scales under all four tires of a machine on a hill, up/down or side hill, and raise and lower 3pt implements and the FEL and see how the weight distribution changes with each movement or load change.

 

[Fallon]

Another interesting thing about these machines is that since all attachments are on the front end loader lift arms, you can easily mess with the center of gravity and traction. So let's say I'm pushing up a steep hill with the brush cutter or finish mower and I start to lose traction, making the wheels spin. The brush cutter and mower are riding on their own wheels, so the machine is just pushing them, not really carrying them. If I pull the joystick out of float, and back just enough the get the mower wheels 1/8" off the ground (the distance isn't important, only that the mower wheels aren't touching the ground), that instantly transfers all of the weight of the mower deck and part of the FEL arms to the front wheels of the machine

The opposite happens with 3pt ballast. If you lower the 3pt control you end up with a code brown or worse. If a tractor ever has the rear end come off the ground, it will "ballance" on the front axle. As the front suspension consists of 1 pin & nothing else, the tractor will then roll to one side or the other.

 

[MossRoad]

What's kind of interesting is that I frequently drive my machine with the rear tires off the ground, only letting them down if I have to make a steering correction.