4WD variations.?

[Builder]

My understanding or maybe misunderstanding of what constituted 4 wheel drive versus 4 wheel assist is that if it has a driveshaft to the front wheels then it was 4 wheel drive. If it had hydraulic motors assisting the front wheels, then it was that 4 wheel assist. Wheel size is not an issue

That's correct. Deere made a lot of tractors with "front wheel assist" which was a hydraulicly powered motor at each front wheel to "assist" with traction at the front axle. It is not a true, mechanical driven front driveshaft from a center transfer case. It was limited in how much power it could deliver to the front wheels, so it was named "assist" rather than "drive".

 

[patrick_g]

Originally Posted by Gary Fowler

"My understanding or maybe misunderstanding of what constituted 4 wheel drive versus 4 wheel assist is that if it has a driveshaft to the front wheels then it was 4 wheel drive. If it had hydraulic motors assisting the front wheels, then it was that 4 wheel assist. Wheel size is not an issue"

That's correct. Deere made a lot of tractors with "front wheel assist" which was a hydraulicly powered motor at each front wheel to "assist" with traction at the front axle. It is not a true, mechanical driven front driveshaft from a center transfer case. It was limited in how much power it could deliver to the front wheels, so it was named "assist" rather than "drive".

That makes it pretty darned clear. Thanks guys.

That distinction (4wd vs assist) was a "convention" to simplify terminology like calling the big metal things that burn gas (or electricity or wood or...) and get real hot on top to cook food "a stove." Worked well.

Anybody know of a CUT with assist?

Many of us will be relieved to know the 4wd tractors we were sold as 4wd tractors and have the same or similar 4wd as our 4wd pickups are in fact (drum roll please) 4wd. Wow what a relief!

Now does anyone care to explain as clearly as the above two quotes just what if any problem there is with Kubota's bevel gear drive? Except for the nearly violent hobby horsing when turned sharply.

Pat

Pat

 

[SPYDERLK]

What is the big deal about full power at all steering angles with a tractor? Full power and traction is typically needed when pulling a plow which is generally in a straight line or when loading the FEL bucket which is also a straightahead direction. When do you need full power/traction while turning hard with a tractor?

Seems to me this is just a marketing gimick.

Suppose you need to go forward while turning and the fronts are sunk in a bit. How about climbimg over a log at full lock. How about trying to steer when pushing and lifting a load. ? Many times it would be helpful to significantly overdrive the fronts when trying to turn hard. Full pull power is always good to have ready at the front. All 4WAs have this. Most arent quite as healthy at as high turn angles as Kubuta can do. The power transmission on them is not the least affected by turn angle. Most tractors tho are limited by wheel turning clearance prior to turn angles where a kubota type system is needed. The very good thing about them on small tractors is good front axle ground clearance.
larry

 

[patrick_g]

Originally Posted by IslandTractor

"What is the big deal about full power at all steering angles with a tractor? Full power and traction is typically needed when pulling a plow which is generally in a straight line or when loading the FEL bucket which is also a straightahead direction. When do you need full power/traction while turning hard with a tractor?

Seems to me this is just a marketing gimick."

I agree that full power in 4wd is a good thing for plowing. When it comes to plowing I have a sub soiler and a middle buster that I virtually never use (and no other plows.)

I find the ability to use full power with the steering turned the max is very useful when using my box blade. For the size of my tractor (39 PTO HP), I have a large heavy box blade. It is a 6 ft box, weighs well over a thousand pounds, and has hydraulic raise and lower scarifiers. It has high sides and holds a lot of dirt when full so is very heavy. I frequently end up in low gear with max throttle when moving the max amount of dirt. Not being able to turn as sharply as possible and or use full power while doing it would really detract from performance.

Surely I am not unique in using full power and full steering deflection simultaneously. I suppose it to be a common practice with folks whose tractors can do it and actually WORK their tractors. Sure there are folks who may have never had the capability so they don't know what they are missing or their tractor is really a lawn mower, or whatever.

Pat

 

[IslandTractor]

Surely I am not unique in using full power and full steering deflection simultaneously. I suppose it to be a common practice with folks whose tractors can do it and actually WORK their tractors. Sure there are folks who may have never had the capability so they don't know what they are missing or their tractor is really a lawn mower, or whatever.

Pat

If real tractor users depend so much on 4wd at full steering deflection how is that only Kubota offers this feature and how did anyone manage before it was available? It still seems like marketing hype to me.

 

[SPYDERLK]

If real tractor users depend so much on 4wd at full steering deflection how is that only Kubota offers this feature and how did anyone manage before it was available? It still seems like marketing hype to me.

Theres no magic to kubotas setup. I thot I said that. You can call it hype, but in truth it offers a small advantage at very hard turn angles - harder than most tractors, kubotas included, are capable of. To repeat - all 4wd tractors offer full power at the fronts when turning. People who use their tractors for a large variety of tasks frequently benefit from this.
larry

 

[IslandTractor]

Theres no magic to kubotas setup. I thot I said that. You can call it hype, but in truth it offers a small advantage at very hard turn angles - harder than most tractors, kubotas included, are capable of. To repeat - all 4wd tractors offer full power at the fronts when turning. People who use their tractors for a large variety of tasks frequently benefit from this.
larry

Got it. (This time)

 

[patrick_g]

I was out this morning brush hogging in the dark by headlights. Some of the terrain was real craters of the moon type stuff. I could have done everything I did with less power in 4wd at full steering deflection maneuvering up hills dodging dirt lumps between eroded places BUT... would have had to back and fill and jocky around if I couldn't use 4wd at high power with full steering deflection.

Over time, improvements to the general state of the practice are more often incremental, evolutionary rather than revolutionary. Someone always has to be first with a beneficial feature. It isa like a spontaneous mutation in the natural world. If it is a disadvantage that lowers survival rates then it will not stay long. If the change is a benefit then it will probably survive and perhaps spread.

To assume having a desirable feature is just hype is not very generous nor likely accurate. No doubt the marketing types do sing the praises of anything that tends to differentiate their brand from another but the engineers probably did not add in this design feature just to be different and arm the marketeers with material for disllcussion.

Maybe it isn't new, improved, and lemon scented but it works for me and I am glad I have it. Speculating that it is pure marketing hype with no facts in evidence smacks of sour grapes.

Pat

 

[IslandTractor]

Maybe it isn't new, improved, and lemon scented but it works for me and I am glad I have it. Speculating that it is pure marketing hype with no facts in evidence smacks of sour grapes.

Pat

I appreciate your point but the inverse is equally true. Speculating that it is anything but marketing hype without evidence seems just to accept whatever the marketing guys tell us. I don't get stuck trying to turn with my Kioti. I assume most JD tractors don't have trouble turning in 4wd either. Where is the evidence that the Kubota feature is a meaningful improvement?

 

[patrick_g]

I appreciate your point but the inverse is equally true. Speculating that it is anything but marketing hype without evidence seems just to accept whatever the marketing guys tell us. I don't get stuck trying to turn with my Kioti. I assume most JD tractors don't have trouble turning in 4wd either. Where is the evidence that the Kubota feature is a meaningful improvement?

I guess just on the face of it I have difficulty thinking that being able to apply more power in 4wd while turning sharply is a bad thing. Why isn't more better in this case?

If folks have a hard time grasping that then I suggest two guys conveniently close together, one with a Kubota and one with the other style should take turns hooking onto the same big heavy box blade of dirt and making doughnuts. Maybe there won't be enough difference to warrant anyone getting their panties in a bunch because they don't have the Kubota feature. Maybe there is a significant difference. Maybe Kubota does worse, who knows. On the surface I can't imagine better full power hard turns to be a bad thing. I do know that I frequently make full power sharp turns under significant load and I wouldn't want to settle for less capability than I have.

Pat

 

[rtimgray]

I agree that some folks are not up to date terminology wise and create confusion when communicating with those of us who are.

So are our trucks really just front wheel assist? I don't think so.

When you engage 4wd you power all the wheels, in many cases in CUT's, mechanically. Whether or not there is sufficient traction to prevent wheel slip at some particular HP output is another matter. So limited slip or not in the rear and like wise in the front is not really the issue just as tire size is irrelevant.

CUT's are intended for extended periods of 4wd as needed and determined by the operator as are pickups. It is, at best, inconsistent to call a truck with a transfer case and a drive shaft that can power the front differential a 4wd truck if the same, nearly the same, or equivalent mechanical configuration on a tractor is not 4wd WITH NO EQUIVOCATION.

I have no problem with the technologically out of date folks using their antiquated terminology. Shucks, I have to be careful to not say ice box and other anachronistic terms. My problem is with those who insist that those of us trained on new technology and terminology are wrong, misguided, or at best marginally tolerated. If a finer distinction is needed to differentiate between styles of achieving 4wd then that too is another issue but so far has not been a hindrance in communications.

Pat

To try to clarify this just a little bit more - the reason that there is a significant distinction between true four wheel drive tractors (the big articulated dudes) and our four wheel drive tractors (that we can switch in and out) has to do with our sales are recorded and reported. I believe that, at least according to some reporting schedules, the tractors that have MFWA, MFWD, or are otherwise known as 4wd actually fall into the 2wd category for the sake of that poll. You could kind of think of it like this - our little tractors are part time 4wd (possibly like your trucks) as opposed to the real 4wd tractors that are full-time 4wd.

Try not to be too hard on folks that aren't up to speed on new vs. old terminology. Whether or not someone calls your tractor 4wd or front wheel assist or happy yankee flypaper has very little to do with its abilities. I refer to my little front wheel assist and mechanical front wheel drive tractors as four wheel drive in casual conversation as well.

Take care.

 

[patrick_g]

To try to clarify this just a little bit more - the reason that there is a significant distinction between true four wheel drive tractors (the big articulated dudes) and our four wheel drive tractors (that we can switch in and out) has to do with our sales are recorded and reported.

Try not to be too hard on folks that aren't up to speed on new vs. old terminology. Whether or not someone calls your tractor 4wd or front wheel assist or happy yankee flypaper has very little to do with its abilities. I refer to my little front wheel assist and mechanical front wheel drive tractors as four wheel drive in casual conversation as well.

Take care.

I guess I take exception with arbitrary distortions introduced for "accounting purposes." How someone collects information and chooses to label column headings to display information that the vast majority of tractor and pickup owners never have and probably never will see and has little impact on daily communications by just plain folks is at best of passing interest, a piece of truth but not important to most of us and likely not to be a trivia question on the Discovery channel's "Cash Cab."

Still, I would be happy to have my tractor and each of my three 4wd trucks referred to with a standardized term such as "s4wd" (Selectable 4wd) should it be introduced and accepted.

Regarding the terminologically anachronistic among us... Hey, I am one too. Recall my ice box example? Like the Will Rogers quote, (Here stated as best my memory can do.) "We are all ignorant, just about different things." We all fall behind in some areas of our complex and fast paced times.

I agree that labels don't make our tractors more or less capable but consistent use of rational labels would sure help us talk about them with less confusion.

Pat

 

[Egon]

Should I say my tractor has part time two wheel drive or part time three wheel drive when the rear differential lock is engaged.??

I do have a truck that has full time one wheel drive and part time two wheel drive. How do I classify this??

In any case what is important to me is the lack of cessation of forward or rearward motion of the tractor or truck!

 

[rtimgray]

Whenever my vehicle experiences the cessation of forward motion and someone asks me if I'm stuck, I just reply - "Not 'til I'm outta gas!"

 

[MossRoad]

Should I say my tractor has part time two wheel drive or part time three wheel drive when the rear differential lock is engaged.??

I do have a truck that has full time one wheel drive and part time two wheel drive. How do I classify this??

In any case what is important to me is the lack of cessation of forward or rearward motion of the tractor or truck!

To answer your questions... Yes, Ford and I agree.

 

[davitk]

Ah, yes, but I am sure there is one thing we can all agree on, out of fuel or not, and that is one never knows the meaning of 'stuck' until one is stuck with all 4 wheels still turning.....

 

[SPYDERLK]

Both wheels on a powered differential axle always drive if in ground contact. Motive force is just limited to approximately twice that of the one with the lesser traction.
larry

 

[Egon]

Not 'till I'm outta gas!"

I'd say "Not till I'm out of diesel" which may actually be true as there are frequent checks made to see if there are debris on the bottom of the tank. If there was a fuel Gage there would probably be fewer checks!

 

[MossRoad]

One more type of drive system...

No transmission.
No differentials.
No drive shafts.
One engine.
One hydraulic pump.
One hydraulic motor at each wheel.
Each wheel is the same size.
The left front and right rear motors are in series.
The right front and left rear motors are in series.
Those two circuits are in parallel.
The unit is articulated and bends in the middle.

Turning the steering wheel to the left causes the front left tire to roll backward while the left rear rolls forward as both left wheels get closer together. The right front tire rolls forward while the right rear rolls backward as the right wheels get farther away from each other. The opposite happens if the steering wheel is turned towards the right. Amazing thing is, no scuffing of the turf happens if you turn the wheel lock-to-lock while standing still, going forward or going backward.

Here's a link to a movie of it turning a full circle in my driveway. No tire slippage on pavement at full lock-to-lock turn. Just a perfect circle turn.

 

[Builder]

Here's a great example of a FWA tractor

1969/ SIDE CONSOLE/ 4020 JOHN DEERE 4X4/ RARE!!!!!! - eBay (item 270273054899 end time Sep-15-08 18:30:00 PDT)