2wd Always?

[N80]

Apparently each persons property, tractor, and style is different.

Certainly. But I'm not sure I understand your example. You moved a pile of dirt in 2wd and it was easy. Well, easy is a relative term. You didn't mention if it would have been easier if you had used 4wd. If you didn't try, then you might not know. If you did try and could not tell the difference, I'd have to speculate that it was because the traction of your turfs is so poor that 4wd couldn't help much.

It has been my experience that I can get the bucket further into anything that gives resistance when I'm in 4wd regardless of conditions. If I can get the bucket further in, I can get more in it. Getting more in the bucket with each pass makes a faster, easier job.

But as you say, there are a lot of variables. When it comes to using the loader I have not yet found any set of variables in which it is even as easy to run in 2wd as it is in 4wd. And I'm running R1s.

Then there is also driver skill. I suspect there are experienced folks out there who can do better in 2wd than some of us can in 4wd. My reliance on 4wd could just be a matter of poor technique.

 

[patrick_g]

It has been my experience that I can get the bucket further into anything that gives resistance when I'm in 4wd regardless of conditions. If I can get the bucket further in, I can get more in it. Getting more in the bucket with each pass makes a faster, easier job.

My reliance on 4wd could just be a matter of poor technique.

Poor technique? Most likely the laws of physics!

To "attack" a gravel or dirt pile there are really only two choices. You either have to ram it a bit to help fill the bucket or use traction to push your way in (4wd does it best) while hopefully gently raising and curling the bucket for the easiest way to fill a bucket. The combined forward and upward motion of the bucket helps fill it with less requirement for ramming speed. Ramming speed works better with sand or gravel and not so great with dirt that has been in place for a while.

With 4wd, as the load in the bucket increases the front wheel traction increases which helps you pull forward to engage the pile. With 2wd when the bucket gets heavier it tends to lighten the rear wheels reducing traction. If you were going to design a 2wd loader you might want to consider front wheel drive.

Cap'n I cannow violate the laws of physics!!!

I prefer to have a fairly heavy implement on the 3PH so I can use all my hydraulics to help fill the bucket. Otherwise I pull the rear wheels into the air when trying to fill the bucket with dirt that has been piled a while. As soon as I start getting the bucket full the weight on the front wheels gives me added traction to powered wheels instead of reduced traction to the only driving wheels.

I may not be the slickest operator but I would challenge anyone to try to move more material with my tractor in 2wd than me operating it in 4wd. I think I would win handily and it is not because I am such a hot shot, it is because I will be working with the laws of physics helping me not fighting me.

Pat

 

[Egon]

Aww, all those technical descriptions are probably driving a true operator to drink!

 

[patrick_g]

Aww, all those technical descriptions are probably driving a true operator to drink!

I think not!!!! A true operator would already be drinking!!!!!!

Pat

 

[ray66v]

Certainly. But I'm not sure I understand your example. You moved a pile of dirt in 2wd and it was easy. Well, easy is a relative term. You didn't mention if it would have been easier if you had used 4wd. If you didn't try, then you might not know. If you did try and could not tell the difference, I'd have to speculate that it was because the traction of your turfs is so poor that 4wd couldn't help much.

It has been my experience that I can get the bucket further into anything that gives resistance when I'm in 4wd regardless of conditions. If I can get the bucket further in, I can get more in it. Getting more in the bucket with each pass makes a faster, easier job.

But as you say, there are a lot of variables. When it comes to using the loader I have not yet found any set of variables in which it is even as easy to run in 2wd as it is in 4wd. And I'm running R1s.

Then there is also driver skill. I suspect there are experienced folks out there who can do better in 2wd than some of us can in 4wd. My reliance on 4wd could just be a matter of poor technique.

To be more specific: I put the tractor in low, and drove toward the pile with the bucket down. No high rate of speed was necessary. The dirt was somewhat wet, but not sticky. The bucket filled without wheel slip, therefore, 4wd was of no use. half the time I had to back up, to be able to lift the bucket, so getting it full was not an issue. The operation had to be done in an efficient manor, since I only have a 1/5 yd bucket. If not, I would still be out there.

I certainly would have used the 4wd, if I needed to. The point was I did not need to. Because of the weight of the backhoe the tractor has no problem with traction. I can even plow snow in 2wd, and I have an over size plow.

The only time the turfs are a problem is in soft mud. I have the luxury of simply leaving the tractor in the barn until the ground dries so that is not an issue.

 

[john_bud]

Ray -
You mentioned the big thing with 2wd tractors and loaders. Weight on the rear. Lot's of it, if you have it you don't need 4wd.

My 2wd tractor has a 3000# backhoe on it and it still needed filled tires. Actually, it needs 1400# of wheel weights too! It only has a 20 cuft FEL bucket and when that is full it lightens the rear so much it can't back up a 1 in 10 grade!

 

[SPYDERLK]

Ray -
You mentioned the big thing with 2wd tractors and loaders. Weight on the rear. Lot's of it, if you have it you don't need 4wd.

My 2wd tractor has a 3000# backhoe on it and it still needed filled tires. Actually, it needs 1400# of wheel weights too! It only has a 20 cuft FEL bucket and when that is full it lightens the rear so much it can't back up a 1 in 10 grade!

Sounds like short wheelbase, well overhung FEL, high CoG. My problem with the 7520, but 4wd makes up for it. In search of a 3000# swinging drawbar.
larry

 

[Egon]

Yes Pat, you are correct!

 

[patrick_g]

There was something overlooked in the 2wd vs 4wd FEL discussion. The operator of the small tractor so successful in 2wd... If we looked at the volume of his bucket and the length of the edge of his bucket in comparison to the weight of the tractor we might find that he has more pounds of tractor for his bucket size than a larger tractor has. This would certainly be a big plus toward ease of filling the bucket.

To expand the concept to ridiculous proportions for illustrative purposes... Consider a small LIGHT tractor with a teaspoon sized FEL bucket. Shouldn't need 4wd to fill the spoon or huge amounts of weight on the back either. A tractor with a large (for its weight) FEL bucket should be expected to have different characteristics and need different operating parameters to optimize its operation.

So again it seems we are comparing apples to watermelons. Just as insects can walk on the surface of water, held up by surface tension, larger animals like people, aardvarks, or fruit bats can't. It is an issue of scale and proportion.

As regards not needing 4wd if only you have enough weight on the rear tires. Yup, 'tis likely mostly true. However, some of us don't want the weight penalty and opt for 4wd to git 'er done without having to haul a lot of weight around all the time. Two approaches, both work, one is more flexible and treads more lightly.

I consider my tractor like a Leatherman multi-tool, a transformer toy. It isn't necessarily the best at any of the tasks it does but it is the best compromise at having a single tool to do many tasks. A tractor can be optimized for a limited number of tasks without requiring reconfiguration. If optimization for FEL work includes oodles of weight on the rear to reduce the limitation of only having 2wd you will suffer traversing soft ground and make much worse ruts than a more lightly loaded 4wd tractor.

There is no one best solution. Versatility comes at a price. 4wd is more moving parts, more front tire wear and sometimes (or often) will not substitute for gross weight.

Which is best? Depends! One thing is for sure... if you have 2wd only you can't select 4wd when it could be just the thing for the task at hand. With 4wd you have a choice. Whether or not someone needs or will profit by having 4wd depends on their requirements. Requirements have a way of changing over time. I personally prefer 4wd for its versatility but not everyone will be best pleased if they adopted my choices.

Pat



Pat

 

[RobJ]

Yard bird maybe. Here is a link that was given in that thread which seems to suggest, if not prove that front wheel lead is more than an urban legend.

Can I use a different size tire on my 4wd tractor

Ok if you want me to eat it then it is done. I'm not married to this one. Hey if balut tastes good, what's a little crow. Heck most of us have eaten rat..errr squirrel.

But a few notes from this un-authored link on the internet...
And since this isn't a white paper from Kubota or deere, I just wonder if the lead spin is actually there just to take up the slack in the gears?

"Negative lead (or slippage) will, from the outset, totally negate any potential advantages offered by front wheel assist."

So if your tires get a little worn, 4wd is totally useless, even though the front is still being powered, say in a muddy condition. Hmmm.. Hey that what it says, it's 100% right...right?

Oh wait, just thought of something, so if you have a 3% lead going forward, then you have a 3% lag going backwards. No wonder people get stuck trying to back out of a hole, the 4wd is totally useless. Yeah good point huh!! (yeah I know, don't bother).

"If you have owned a 4wd tractor for any length of time, you have probably noticed that the front tires have a tendency to wear at a higher rate than the rear tires."

Which means you should replace them more often of you have a useless w4d. Actually George, you don't need to jack up your tractor to check the ratios, if you run straight, in 4wd, on some powered soil or wet close cut grass, or some just damp ground, you should see the tracks left by the front tires slipped or dragged a bit as the front tries to pull the rear. Check that out this weekend and report back if you think about it. If you don't see this, then you are out of spec and your 4wd is be totally useless!! IE my back tires on my 2wd leave a nice flat impression..unless I'm turning of course.

"only at much lower speeds with the associated tire wear being nearly imperceptible."

Wait, they wear at a higher rate or not?? My rears wear at an imperceptible rate if you ask me. They should last decades! My BIL L175 still has it's mid 70's rears and they look pretty good

"in effect, trying to "outrun" the rear axle. Since the rear axle is supporting 60% of the total tractor weight, the front axle cannot drag the rear axle along with it at its slightly increased speed; therefore the front wheels must be content to slip (or spin). "

OK here is where I have a problem. Since this is true, then more wear and tear on the front drive parts will occur. Ever wonder why the first dog in a dog sled looks more tired than the others? He's dragging the others around!! Yeah I would run mine in 2wd until needed. ANd not like when you are already stuck, say before you cross the mud hole..

And I guess the article left out the all important tire pressure as George mentioned. So if your fronts are a little low, don't even bother with 4wd because it will "totally negate any potential advantages". Hey if your in a lag then that's what the article says right?

Don't worry, I'm sure you haven't heard the last from me on this yet!! To bad huh.

So mark your calendar, bookmark it, here it is. YOUR RIGHT!! (see above).

BTW, I think I'm going to convert my tractor to 4wd with a 3.78941 lead ratio. Any thoughts?