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 | DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada 
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2003-06-06 56788
I posted this in another thread but it belongs here too:
I must remember to temper my comments with the facts of where I live and the character of my land.
Many folks could get by with a 2wd CUT if it was heavy enough. I could not. Without 4wd, carefully selected tires and lots of ballast I have trouble running any tractor on my sandy, steep lot.
The other day I was driving my JD 4100 down a slope right next to the house in 2wd in a low gear using engine compression to control the speed.
I was feeling pretty smug because I felt I had finally found the right combination of rubber and ballast that would let me operate in 2wd about half the time instead of 4wd all the time.
Wouldn't you know it? Just when you think you got all your poop in one sock the tractor bites you.
Halfway down the slope the right rear tire rolled up on a smooth round rock about the size of a grapefruit. The problem was that it didn't roll over the rock instead it started pushing it ahead of the tire like a big ball bearing.
The other three tires, having no real mechanical connection to the engine, began to free-wheel and the tractor took off down the slope.
About eight feet later the tire finally got over the rock, which lifted the rear end up and slammed it back down, and re-engaged the drivetrain/engine compression which slammed me forward in the seat.
I came within inches of crunching the whole thing into the house and my neck and back hurt for two days.
I guess I am back to using 4wd for the majority of my operations, and that is why I tell my better third (calculated by weight)that she should just leave the 4wd engaged all the time.
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 | Misenplace
Join Date: Jul 2003 Posts: 875 Michigan 
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2003-06-06 56793
I had a shop teacher in grade school that used to say " A tool is never dangerous untill you become too comfortable with it." I have tried (foolishly) to prove him right many times over the years. I find that like you I need 4wd nearly all the time. Every time I try to conserve and go to 2wd I wind going to fast....of course the tractor has to remind me of this. ....
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 | Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
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2003-06-06 56795
Mark, thankfully a few sore muscles was as bad as it got.
I think it has been mentioned a few times before, but it bears mentioning again, the differentials in tractors are such that one wheel stopping or changing speed can cause an adverse reaction in the others. In an extreme case it can cause one wheel to counter-rotate, or spin backwards.
The best, safest solution in this case, operating on a slope like you did, is to engage the diff. lock and stick both wheels together mechanically.
Best of luck. ....
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 | AC5ZO
Join Date: Jul 2003 Posts: 928 Rio Rancho, NM 87144
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2003-06-06 56798
Mark I live in the mountainous desert area of NM and I expect that our land has some similarities. It sounds like a pretty wild ride, but it also sounds like it ended as well as could be expected.
Before I bought my NH TC45, I was actually looking at Bobcats. I rented one and the skid steer action would dig itself into my soil in nothing flat. I had to use my pickup to winch the Bobcat out of the holes it dug. I use 4WD at all times except when I am on flat and level with very light loads on the FEL. I have R4 tires, so I do get some grip from those. Even on flat and level, the 4WD helps when carrying loads in the FEL, because otherwise the front tires tend to dig in like the Bobcat.
The dirt here is very dry and sandy. We have had only about 4 inches of rain since the first of the year. When I head down a slope, I try to use engine compression to keep things under control. I don't drive down a slope that I have not tried to back up before, because I know that I won't get stuck down in the bottom of some arroyo and have to be pulled out.
In addition, the soil is so fragile that I try to keep on the same tracks as much as I can. I use the bottoms of the arroyos as some of my main trails on the property, so I am constantly driving into and out of them. What I end up with are some tracks that I have tried and proven before, so I don't have to take extra caution every time I am out. I have to maintain them, because when we get rain it is in the form of monsoons and it is not out of the question to get four or more inches in a one hour burst. That has the tendency to flash flood and run down my tractor trails and rut them out. So, after things dry out, I go to the bottom of the hill and bring the dirt that washed out back and fill in the ruts.
I have not had the situation that you describe with the rock on my rear wheels, but it has happened on my trailer. In most soil, I think that the trailer would have just bounced over the rock, but as you described, the rock just pushed ahead of the tire and cut a small groove in the sandy soil. I had to stop, back up and get the rock out of the way by hand.
I am glad that everything turned out OK for you with the exception of a few sore muscles.
Most of the time when I do this climbing on a hill, I keep my left and right brakes locked together. My thinking is that I don't want to hit one of them and cause a slide in the marginal traction. And in 4wd, I should have braking on all wheels linked through the manual transmission. But, in the situation that you describe I wonder if using an independent brake to halt the opposite wheel would have forced the blocked tire over the rock?
Another thing that I am wondering about is a feature that I seldom use on the tractor, and that is the differential lock. I use differential lock many times in my off-road trucks in deep sand and rocky terrain. I wonder if it would be better to engage it for the tractor on these steep sandy hills? ....
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| AC5ZO
Join Date: Jul 2003 Posts: 928 Rio Rancho, NM 87144
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2003-06-06 56799
Murf, we were apparently posting near the same time. You answered my question about the diff lock. ....
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 | Chief
Join Date: Jul 2003 Posts: 4297 Southwest MiddleTennessee
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2003-06-06 56808
Mark, glad to hear that you were not seriously hurt and no damage to the tractor. Welcome to the "Man of Steel Club". ;o) ....
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 | TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
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2003-06-07 57009
I did mention the diff lock awhile back. It would increase traction and also prevent counter-rotation. However, if steering were required the lock would be a liability. When it's engaged, the front wheels tend to turn and skid. The tractor doesn't turn much. Steering with the diff lock engaged is both a safety issue as well as being hard on the drive train.
I leave my brakes locked together for the same reason since I have started out across the yard a couple of times by forgetting they were unlocked and then hitting only one brake. I wouldn't want that to happen on a steep slope. The only times my brakes are unlatched is when I'm actually brake steering or occasionally to help the steering when doing heavy loader work. I heard somebody say that separate brakes could be used to help keep a tractor straight in a downhill slide but even he acknowledged that it's not a very practical idea.
Mark: Good think the slide stopped with little damage to you or property. If your tractor has HST the TX may have been more effective than the engine in stopping the slide. Diesels don't have a lot of engine braking. HST braking is a very good reason for people with HST's to avoid using cruise control when on slopes. The fact that the slide stopped in time of course is more important the reason why.
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| DRankin
Join Date: Jan 2000 Posts: 5116 Northern Nevada
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2003-06-07 57028
The tractor in question was the 4100 Gear and I was running in 3rd or 4th out of eight forward gears.
The whole scenario was like one of those trained seals rolling around on a big ball. The instant the drive wheel got done "digesting" the rock and came back to earth the whole process came to a screeching halt.
There was not time to even step on the brake, it just happened too fast. But I think I did take my foot off the gas pedal which just made the stop that much more abrupt.
The use of the diff-lock is a good idea.... on that tractor. On my BX it does not seem to want to stay engaged unless I hold the pedal down all the time. ....
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| AC5ZO
Join Date: Jul 2003 Posts: 928 Rio Rancho, NM 87144
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2003-06-09 57165
I needed to move some large rocks weighing several hundred pounds this weekend. It was necessary to go on some steep hills and even traverse across some slopes. This is rocky desert terrain in New Mexico. The soil is sandy and dry. This is similar to the condition that started this thread.
Based on some of the discussions that we have had in this thread and others, I decided to try some things. Baseline information...My tractor is a NH TC45 4WD with 16LA Loader with calcium loaded R4 rear tires.
Some of the travel was not comfortable because of the sloped ground. Traversing the side slopes was the most uncomfortable. From a "personal comfort" standpoint, I felt better driving up the hills with the weight in the loader rather then backing up the hills, but I could make the slope either way. All travel used 4WD and both brakes locked together.
When traversing across the slope, the front end definitely had a tendency to slide down the hill with the weight in the loader. Engaging the differential lock definitely helped keep the front end from sliding down the hill. When going through washouts and over small rocks, the differential lock also helped. Lesson..I will rely on the differential lock more than I ever have before when driving in straight lines and especially on side slopes and rocky terrain.
On one occasion I was driving down a smooth slope with a large flat space at the bottom. I had no load in the FEL. I have a 12X12 synchro shuttle transmission. I can generally downshift or upshift as needed. But, on the hill, the speed comes up so fast when you engage the clutch to shift that you cannot do this on a sloping surface. In this case, I did not shift, but just let back out on the clutch slowly. The speed was caught, but the rear wheels may have skidded a bit during the slow down. As I said, this was not a dangerous position to try this, because of the wide open run out area. The lesson here is to pick a speed and stick with it. If it looks tricky start out slow and stay there. With a HST, you may have more variability, but reducing speed on a hill is like braking and can cause a skid.
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| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
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2003-06-10 57259
I think that everybody to a large extent develop their own operating styles and eventually do what feels best. This discussion has been pretty good at introducing some ideas and getting us to think and maybe try different ways of doing things in relatively safe circumstances. It is I think everything that should be happening here. Nobody is always right or always wrong and there seldom is a completely right way or wrong way of doing something. Everybody can learn something new and so we have.
I'll add that the idea of using a diff lock should be tempered by the notion that when it's engaged, if you need to steer you can't. For myself, what seems reasonable is to decide if the risks of tipping or sliding are greater and I'll probably do different things accordingly. I still don't know whether I'd rather slide down a hill foreword or backwards. It's a choice I'd rather not have to make. Some of the idea of backing up hills may be due to older 2wd farm tractors that often didn't have loaders and were heavy in the rear for traction. Weight distribution tends to be more equal on newer compacts and maybe tendencies to backflip are reduced. It still is an issue though.
No clutching on hills is a strong argument for HST's. I have a 12 x 4 synchromesh myself. Speed picks up rapidly on a hill and diesels don't have much engine braking. Clutching is a bad idea. When I road the tractor even when unloaded except for loader and a heavy 3ph implement there's enough push going down hills for the rpm to exceed the max-no load point. I slow down before creating hills so I don't have to use the brakes.
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