2wd Always?

[texasjohn]

I'm 4WD all the time for traction/braking except when on pavement.

 

[SPYDERLK]

Biggest reason is safety. With 4wd, you also get 4 wheel brakes. On my tractor, it has to be just so (all tension off the gears, etc) to get the thing in and out of 4wd. If I left it in 2wd, I can see myself getting into a ticklish situation needing 4wd and not being able to get the lever to go. I leave mine in 4wd unless I go all the way down my driveway. Half way? It stays in 4wd.

Ralph

All my tractors go in easily if im moving. If they dont go in at a standstill, moving ahead slowly will get them in. Most come out easily too when going straight. If not, I accelerate then let off and quickly operate the lever. Works every time.
larry

 

[SLOBuds]

WOW.

I have been on TBN for quite a few years now, and I have never seen this 2wd vs 4wd debate before! Hey - what makes the world go round, right?

My L35 just putts around on my 10 acres, though it seems to work plenty hard during those putts. And the parcel is hilly with many solid pucker-power spots. So if it's the same to everyone I think I'll just stay in 4wd.

Looks like the answer to this is NOT what I imagined going in.

Thanks for the feedback and ideas.

 

[john_bud]

Heck, I'm gonna go weld my tractor lever in the 4wd position and add 2 extra sets of tires on both axles!

Sorry, these discussions make my brain hurt ("It will have to come out!").

1) 4wd is slightly harder to turn and will be slightly wider (about the 5-10% mentioned above)
2) 4wd does tear up the ground more. Not noticable on firm soil but obvious on loose spring soils!
3) 4wd does use slightly more fuel per hour. But you will need to keep tight records to learn just how much more.
4) It might wear more in 4wd, but skipping one greasing is probably more damaging.


This is my typical operational method. I use 2wd for things that don't need traction (using a 3pt sprayer, 3pt spreader, going to a different field). I use 4wd for things that need traction (FEL work, pulling any ground engaging implement, etc). Some times I find that it's been in 2wd after a day of box blading - oh well. Some times I find that it's in 4wd when going 2 miles down a dirt road - oh well.

jb

 

[Z-Michigan]

Someone mentioned 4 wheel braking.

May I correct that statement?
Most tractors that I know of only have brakes on the rear wheels.

Yes, that's right, but the point is that in 4wd, because there is a solid link between front and rear axles, applying brakes (which only directly affect the rears) uses the traction of all four wheels/tires.

I have fairly flat land and tillage is a small part of what I do. For me, using 2wd most of the time makes sense. I use 4wd when I need traction (including to reduce slip in tillage), for doing heavy FEL work, or in the rare instance that I'm on the one small incline on our property. Otherwise, for my mowing and light FEL tasks, 2wd works great, and 4wd would be pointless. Your situation may vary.

As for turning radius - it depends on the traction situation. When traction is awful, I get tighter turns in 4wd. When traction is great, I get the same or tighter turns in 2wd. In most common traction situations I can't really tell a difference. I have a system with U-joints on the front axle shafts, not the Kubota bevel gear system.

 

[Rara Avis]

Well JD Operator Manuals state that you are supposed to be in 2WD when operating on pavement or moving the tractor without engine running...

Here are some more notes...in JD manuals

Caution: Front-wheel drive greatly increases traction. Extra caution is needed on slopes. Compared to 2-wheel drive, a font wheel drive tractor maintains traction on steeper slopes, increasing the possibility of a tip over.

To increase front tire life, disengage front wheels when transporting tractor. To provide 4-wheel braking, engage MFWD.

NOTE: Disengage front-wheel drive before driving at fast speeds or on paved surfaces.

 

[N80]

None of my 3 Kubotas, nor any of my tractors have as tight a turning radius in 4wd as in 2wd. The difference is in the 5-10% range unless you use the brakes in 2wd.
larry

There must be something wrong with your 3 Kubotas. In a bevel gear system there is absolutely no reason for the turning radius to be larger in 4wd in 2wd. The angle at which the wheels turn is identical and there is no palpable binding of gears. Again, I've measured it on mine, not eyeball, but with a tape measure. No difference. None. It is certainly conceivable that there is a difference between models. Mine is an L4400.

 

[N80]

Sorry, these discussions make my brain hurt.

You're probably going to need a few more aspirin.

1) 4wd is slightly harder to turn and will be slightly wider (about the 5-10% mentioned above)

Not on my tractor. And if it were true, it would stink. My plowing, mowing and disking is done in tight places. Adding 10% turning radius would be a deal breaker for me. That would really stink. If that is true on other tractors, well shoot, maybe some of you didn't do your homework.

3) 4wd does use slightly more fuel per hour. But you will need to keep tight records to learn just how much more.

This depends. See my example above (plowing). For just putting around, probably true. But in that case 'slight' is the operative word.

Also, as far as my Kubota Manual, there is only one reference to taking it out of 4wd and that is for extended use on pavement and even then it only says to do so to avoid excessive tire wear.

The quote from the JD manual about extra traction increasing your risk of roll over is simply bizarre. I'm not saying that there is no situation where that is not true, I'm just saying that compared to 4wd there are many more opportunities to wreck a tractor on a slope in 2wd.

 

[SPYDERLK]

There must be something wrong with your 3 Kubotas. In a bevel gear system there is absolutely no reason for the turning radius to be larger in 4wd in 2wd. The angle at which the wheels turn is identical and there is no palpable binding of gears. Again, I've measured it on mine, not eyeball, but with a tape measure. No difference. None. It is certainly conceivable that there is a difference between models. Mine is an L4400.

Yes, it must be some difference in models. Theres some sort of magic going on. The problem that arises with 4wd turning is that the tighter the radius being turned the more discrepancy exists between the summed distances moved by the fronts and the rears. The tighter the turn the further the fronts go compared to the rears. Fronts that are well overdriven are great for turning, but fronts that are driven just right to work neutrally along with the rears when going straight are not. In turning these fronts are being pushed by the rears, but being forced to run at the same tread speed as the rears by the linked system. They slide causing a wider circle. Normally, fronts are overdriven slightly, gently sratching along trying to stretch the tractor. More would be better for maneuverability, but with a loaded loader and counterweighted tractor the forces on the drivline would be abusive when going straight. It becomes a balancing act. I dont see any way this system dichotomy can be fully resolved in a system hard linked front to back.
larry

 

[Egon]

Whatever; my toy tractor stays in four wheel drive both in the paved driveway at home or out at the play farm. Both are steep enough so that it is required to enable me to drive up the driveway or the hills.

Others will have different situations!

 

[SPYDERLK]

Whatever; my toy tractor stays in four wheel drive both in the paved driveway at home or out at the play farm. Both are steep enough so that it is required to enable me to drive up the driveway or the hills.

Others will have different situations!

Yeah my toy tractor hardly notices it either. But still, in 4wd on a gently uphill, flat, or downhill turn, where it becomes evident Im not quite gonna make it, a quick flip of the lever and the front end slews over as the fronts freewheel and I make the turn with room to spare.
larry

 

[NewToy]

Biggest reason is safety. With 4wd, you also get 4 wheel brakes. On my tractor, it has to be just so (all tension off the gears, etc) to get the thing in and out of 4wd. If I left it in 2wd, I can see myself getting into a ticklish situation needing 4wd and not being able to get the lever to go.ve mine in 4wd unless I go all the way down my driveway. Half way? It stays in 4wd.

Ralph

Sounds like your gravl drive is somewhat steep as is mine. On around the third day I had my tractor I was going down with a pretty good load of stone on my trailer in 2WD and I started breaking loose in 3rd gear hi. I was able to accelerate and "get the wheels back under me" but it was quite hairy, going a bit faster than I wanted to. After that I never go down unless in 4WD and the extra traction/braking is amazing. It feels like there is actually another set of discs on the front. I was like "Piloon" thinking there are only rear brakes but that 4WD is a pleasant surprise.

John

 

[N80]

Normally, fronts are overdriven slightly, gently sratching along trying to stretch the tractor.

I have been told, or I read it in the shop manual, that the fronts on the L4400 are slightly overdriven.

 

[D7E]

Run 2wd unless the situation dictates 4wd...

Pretty much sums it up for all sizes.....Why extra wear and tear..???
Seen some good examples on loader tractors today on auction sold with prop-shafts removed and running as 2wd with stripped crown wheels..?
Spent their life in 4wd..??

 

[wolc123]

In general, it is best to use 4wd whenever you are off the pavement, especially on soft or tilled soil. The reason for this is because energy is wasted pushing the dead axle, and that costs money for fuel. For tillage work, a 4wd may require around 25% less fuel to do the same work. Most CUT users cant grasp this concept because they are much more familiar with on-road automobile operation, where 4wd almost always uses more fuel. The pavement can not absorb energy like the soft ground can.

 

[ray66v]

I run 2wd, unless I need 4wd.

I have seen the front tires wear out on my fathers tractor, because of being in 4wd all the time.

 

[D7E]

In general, it is best to use 4wd whenever you are off the pavement, especially on soft or tilled soil. The reason for this is because energy is wasted pushing the dead axle, and that costs money for fuel. For tillage work, a 4wd may require around 25% less fuel to do the same work. Most CUT users cant grasp this concept because they are much more familiar with on-road automobile operation, where 4wd almost always uses more fuel. The pavement can not absorb energy like the soft ground can.

This is questionable as the fwd takes power to propell so if on hard dirt or not laden down is unneccessary .For example i have a 40KPH tractor which if left in 4wd on highway will noticably take more power ,Flick the switch and the rpm's will decrease by 1-200 ...?
Why do modern ag tractors have an automatic function where when you lift the 3pt the fwd kicks out automatically ....To save wear and tear and make turning easier...?

 

[SCDolphin]

I try everything in 2wd first. If I have a traction problem then I switch to 4wd. I do less turf damage in 4wd unless I try a tight turn then when the 4wd is engaged: it seems to cut the grass more. The R4 tires don't have any traction on wet grass or clay as compared to the coventional ag pattern

 

[N80]

Seen some good examples on loader tractors today on auction sold with prop-shafts removed and running as 2wd with stripped crown wheels..?
Spent their life in 4wd..??

That's speculation. I've seen all sorts of things damaged on used tractors. I'd suspect abuse or poor quality before I'd suspect that it was due to a 4wd tractor spending its life in 4wd. I'm not sure why folks can't understand that a 4wd tractor is made to spend its life in 4wd!

I'm personally glad that I don't waste any time wondering if or when I need to be in 4wd and the only time I do waste on the issue.....is here.

 

[N80]

Why do modern ag tractors have an automatic function where when you lift the 3pt the fwd kicks out automatically ....To save wear and tear and make turning easier...?

That sounds like speculation too and I'm sure the answer is system specific. Large ag tractors often have little in common with small utility and CUTs. And I wouldn't own a tractor that did that (unless there was a full time override) since that sort of behavior could get you killed on a wet muddy hill.

As far as fuel savings, some owner's manuals say specifically that 4wd is more efficient, though mine does not. An example has already been given above.

I do think people confuse modern CUT 4wd systems with the older automotive systems they are used to.