How much side slope can my tractor handle?

[Gunny]

For me, if it doesn't feel good, I don't do it. I've got one hill on my place that I always mow up and down, others have said that they would have no problem mowing across it. I've told them that any time they want to mow it, go ahead, but I'll just keep on doing it my way

 

[ericm979]

"butt crimp" can vary widely between individuals- some people are cautious, others are not. A certain one of my neighbors would roll a tractor within the first hour of operation.

For what it's worth the only spec I have found for compact tractors is for the Massey 1700 series- 20 degrees max in all directions.
That's more than I'll do on a side hill on my B7100 but I know I have slightly exceeded it going up or down as my private road's got sections that I measured at 23 degrees.

 

[CobyRupert]

"butt crimp" can vary widely between individuals-

So true.

Also, this feeling can have nothing, or I should say, can be disconnected from, the actual steepness.

Last fall I was mowing at the top of a hill that get progressively steeper at the top. So when you're near the top you're a good 200' elevation above the bottom. So there's a bit of vertigo sensation going on at the top that one doesn't experience if you're mowing a ditch. IMHP, it feels like you might fall off the edge of the world (for this part of the country). So even though the ditch may be steeper, it's "butt crimp" would probably be less.

On this hill my rational mind says "No problem. Totally safe." But with the tractor rev'd up to 540 rpm and 7' of spinning blade on back I chicken out. Then I get off the tractor, look at it again, look at how the tractor is tipped and think "No problem, it would have to be twice as steep!", get on again, go a few feet and feel the slightest dip on the low side, and the tractor "tracking" downhill; rational mind say "No problem", but the part of my brain operating the levers and clutch say " Nope! I'm outta here!".

So yes, most people will quit before the tractor does.
Acclamation is also a factor. I'm sure if I went out there day after day, I'd bet I'd used to it and could mow it (Assuming I could stay in the seat. - Yes, I DID put seat belt on, rare occasion, for sidehill.)

I also agree: Set tires to widest. Fill tires. Also leaving bucket on and low will lower center of gravity and provides a "screen" for finding objects or knocking over hydraulic-line ripping branches before you drive over them. Especially if you don't have under- guards. THe suggestion of putting gravel in bucket, and keeping it low helps even more.

 

[Looking4new]

I mow straight up or straight down, I don't really care what the pattern 'looks' like. I know what my tractor cost me and I don't want to have to replace it over 'looks.'
Beauty is in the eye of the beholder and my tractor looks like a beauty sitting on all fours with straight tin.

 

[ovrszd]

I was Deployed late 2005 thru late 2006. My wife was left with the task of mowing. She was very concerned about tipping the tractor. I bought a cheap tilt meter and installed it on our Kubota B2910. Told her to use the gauge to get accustomed to the tractor and it's abilities. Told her to never exceed 15 degree side slope. The tractor was amazingly stable at that angle so figured I gave her enough cushion that she wouldn't have problems and she didn't.

Here are some pics I took of that tractor using a rope hanging off the ROPS to show actual tilt of the tractor as well as the gauge. I posted these pics on TBN nine years ago as an example in a thread similar to this. I think any tractor will function at 15 degrees. Obviously I'm wayyyy past that in these pics.

Maybe purchase a tilt meter and do some experimenting on your own to find your "safe" place.

 

[CobyRupert]

Here's a good paper on overturn hazards.
View attachment Tractor Overturn Hazards 202[1].pdf

When you look at Ovrszd's first picture, you can almost image that the center of gravity's (COG's) height is probably less than a foot above the PTO shaft. (or maybe less if one has loaded tires).
Only when the slope is such that the tractor's COG rotates so that it is over the top of where the downhill tires contacts the ground (loose approximation*) will it roll over.
Now there's been a lot of argument on pivoting front axles effect, etc.. and this ignores momentum (travel speed) when you hit a dip, or when your sliding sideways tire then grabs, but you can see it would take a good slope to roll.

 

[ovrszd]

Here's a good paper on overturn hazards.
View attachment 495421

When you look at Ovrszd's first picture, you can almost image that the center of gravity's (COG's) height is probably less than a foot above the PTO shaft. (or maybe less if one has loaded tires).
Only when the slope is such that the tractor's COG rotates so that it is over the top of where the downhill tires contacts the ground (loose approximation*) will it roll over.
Now there's been a lot of argument on pivoting front axles effect, etc.. and this ignores momentum (travel speed) when you hit a dip, or when your sliding sideways tire then grabs, but you can see it would take a good slope to roll.

Yep. A friend of mine who is much smarter mathematically than I used that picture to draw in what you are saying. He assured me the tractor was not close to tipping. It didn't feel tippy at all. I've mowed that bank hundreds of times with various tractors. The B2910 had loaded rears.

My comment concerning wide front axle versus tricycle. The wide front axle only helps prevent tipping when the tractor has oscillated on the front axle pivot to the point that it hits the bump stop. By then you will have already messed yourself.

I've had my Kubota in that situation several times using the FEL with Grapple. One rear tire is a LONG WAYS off the ground by the time the oscillator hits it's stop point. Far enough that if you are headed downhill at the same time the rear tractor weight starts leveraging you over just as you explained about the COG in your comments above......

 

[RaydaKub]

As many have noted, try to avoid the side hill whenever you can. You have to sort through the advice given also, and in a dynamic situation such as tractors on hills, much of the good advice contradicts other good advice.

For example: Mowing up and down hills is good. With a bushhog, you might need the loader on for front end weight so you don't lift the front wheels while going up. But if you have to turn on the slope, there is a brief moment when you might be on the sidehill. At that point, the loader is your enemy, transferring weight forward onto the tippy front axle. Then it becomes your friend again as you head back down the hill because if you lose traction, it becomes a good emergency brake. On my hill, the tractor with fel will slide down hill in 2WD and I've used the emergency brake on the front. But w/o the fel on, it doesn't slide in 2WD. The fel will transfer enough weight forward to cause a problem, but then is a great solution to the problem it created. 4WD and no fel is the best solution available, but not always possible.

My point is, there is not single piece of advice here that will keep you safe all the time. Awareness of the possibilities and paying attention to your own pucker factor is the best.

 

[RedNeckGeek]

Lots of good info here that closely parallels my own experience. Just one or two things that are subtle and do make a difference.

The attachment points for the FEL on my Kubota are above the Center of Gravity (COG) of the tractor, so whenever the bucket is off the ground it will exert a tipping influence, especially on a side hill. Dropping the bucket eliminates the tipping force immediately, so when things get steep I keep a hand on the FEL control and have developed a reflex to push that handle hard into the float position. That said, having the bucket up can act as an early warning that tipping is imminent, and provide a way to stop it when I feel a back wheel lift. For that reason I would never use the tractor on a side hill without the FEL in place. Without it, i'd have no way of quickly stopping a roll over.

I use a gully located at the bottom of a steep hill as a rock dump and compost heap. Whenever I'm headed there, the bucket is always full, and if it's got rocks in it, it's also very heavy. The hill steepens as I get closer to the trail down to the dump, so much so that I often have to drop the bucket and let it skid along as I make the turn to head down hill. If I just lower the bucket until it's just skimming the ground, I can feel the uphill rear wheel lift until the bucket comes into firm contact with the ground, arresting the roll over. Not a great way to run a railroad, but sometimes I just have to make do.

I recently had the misfortune to remove a LOT of downed wood from my steep back hill. To get the job done as quickly as possible I piled as much wood as would fit into that bucket. That made it a lot heavier, and consequently the tractor was a lot more tippy. For most of one afternoon I ended up making long traverses of the hill at a slight angle from straight up and down just to keep the tractor from tipping. I'd end up going up 75 feet to move over 20 feet, but that's what it took to stay safe.

Someone else mentioned getting accommodated to the slope, and I have to admit that does happen to me. I mow my lot maybe three times in the spring, and that's it for the rest of the year. Outside of that, I'm not on the steepest part of the property with the tractor. To cover the whole lot takes about three days of maybe six hours each, and I find myself getting into steeper sidehill situations with lower pucker factor as I get more seat time. A couple weeks go by and I need to mow again, and the pucker factor seems to have reset and it takes a bit of time to get comfortable with it again. However, all it takes is one unexpected wheel lift to turn me back into a nervous nellie, sometimes enough to find something else to do for the rest of the day.:shocked:

Also mentioned was going slow. If I'm going slow and a down hill wheel drops into a hole, or more likely at my place, an uphill wheel starts going over a stump or rock, I have time to stop the tractor before it rolls. That gives me time to think about what to do, be it lower the bucket, steer down hill, or back up and find a different path. Or just inching over the obstacle very slowly, ready to back up if a wheel starts to come up.

I'd never used a tractor until I moved here, and fortunately early on found threads like this on TBN that made me aware of the hazards and what factors were involved. That's helped me evolve a risk management strategy that so far has worked for me, but that hasn't stopped me from making sure that the ROPS is always up and pinned in place before entering a side hill, and always always making sure my seat belt is on.

 

[plowhog]

Coby, that's a great technical write up. Thanks for posting.

What I have learned is be cautious, and go slow. For safety, I will inspect the area to be bushhogged before mowing, looking for rocks, dips, and obstacles. I considered purchasing a dash mounted slope indicator but instead have another idea.

I used to fly multi-engine airplanes. In a safety training flight, the instructor taped a piece of yarn on the outside center of the windscreen. (Must have been good tape!) If the yarn was blowing straight up the windscreen, you were in coordinated flight. If it was to the left or right, something was wrong. Incredibly simple training aid but more effective than all the gauges and digital displays. As you transitioned from simulated engine failures, where a lot of things were changing at once, you could immediately see how well you were doing. So, I'm going to hang a piece of yard from the roof of the cab. I'll figure out how much "lean" I am comfortable with, and then keep to that limit.