Gear drive vs hydro

[MossRoad]

.. hey.. at least i restrained myself from using the 'riding lawnmower' analogy at any point in this conversation.. :0

soundguy

DOH!

 

[N80]

I think you could also say that real work is work that you would have to pay others to do.. if you weren't doing it yourself.

IE.. I'd ahve to pay others to mow my fields for me.. If i didn't mow them. At current mowing rates... It's MUCh cheaper for me to mow them per year.. even figuring the cost of the tractor i bought to do so... If I paid to have them mowed.. I'd have to let them grow up alot more inbetween cuttings due to the price.. etc.

soundguy

Good point. But for some of us weekend warriors like me, that type of work doubles as entertainment. And I won't lie, even though mowing is my least favorite tractor work, I still end up enjoying it. And I have a blast doing most everything else. I even enjoy the maintenance. There are times when I have other things that I want to do which makes me want to get a tractor job done real quick, but that's pretty rare.

And I think that most of us here fall into that catagory...or we probably wouldn't even be here fussing about our tiny little tractors. And that means that most any discussion about trimming minutes or hours with the efficiency of one tranny vs the next are not sincere.

There are usually half a dozen active posts about from people rejoicing about HOW MUCH seat time they've gotten lately.

(There are obviously people here, who don't enjoy tractor time as much as some of us, or for whom it is employment and certainly the 'time' issues are more important to them....but again, this is not typical of the BX Nation.)

 

[MossRoad]

As far as real work and getting paid...

I volunteer at the school, church and little league a few days worth of tractor time, operator and fuel each year. I think I have more hours on the meter in volunteer work than work at home each year. Definitely this year. We had no rain, so I didn't have to mow at home.... the grass died early.

 

[art]

Me too, but that's because I don't know anything about HSt other than a test drive in a parking lot 3 years ago on a tractor I knew I wasn't going to buy...all I remember is pressing a pedal.



Makes sense I guess. So the throttle and the 'pedal' are seperate things? In other words, set the throttle to 2100 rpm which means PTO goes 540 and then work the 'go' pedal seperately and go as slow as you want but keep constant PTO speed? That's cool. So you can creep around obstacles and still maintain good mower blade speed.

Okay, that's neat, but again, we're still sort of splitting hairs here since with a gear tractor, especially some of the ones cited above with ground speeds of .24 mph at 540 pto speed, you can still go painfully slow while keeping good pto speed. Maybe not technically as precise.....but in practical terms, maybe a wash?

(Sorry to be thinking out loud, I'm just trying to think through this and I don't have any HST experience and with my tractor second gear is slow enough to mow around shed, cars and house. Which means I don't have a lot of experience using first gear even in my own tractor!)

Alright, so to justify your perspective you can slow a gear drive down by using the right gear to get the job done! So let's just say that you have mixed conditions and one moment the .24 mph works but the next few hudred feet you could go 2.4mph! Do you shift gears or just stay at the same speed? Time is a thing that you can never replace, once it's gone it's gone! Only a hydro will allow you to speed up and slow down the have a perfect job and not shift a gear! That is also the same transmission that allows you to work with a machine hooked up to it that might be to big for most curcumstances but with the flexibility of the ground speed you can overcome that even with the loss of power caused from the hydro!

 

[N80]

Experiences will vary, and I've done very little actual volunteer work, but I have helped my B-I-L when he has needed smaller tractor services (moving feed in his feed lot, cleaning feed lot. moving and spreading gravel around his cisterns, disking his veggie garden (so his wife doesn't have to hand till it!) etc) I not only enjoyed it, but it made me feel good too.

 

[N80]

Alright, so to justify your perspective you can slow a gear drive down by using the right gear to get the job done! So let's just say that you have mixed conditions and one moment the .24 mph works but the next few hudred feet you could go 2.4mph! Do you shift gears or just stay at the same speed? Time is a thing that you can never replace, once it's gone it's gone!

Funny that you mention it but we are talking about the time issue right now. Clearly I don't find that 2.3725 seconds it take me to stop and shift as valuable as some.

Only a hydro will allow you to speed up and slow down the have a perfect job and not shift a gear!

That's not even remotely accurate! I can change ground speed significantly with the throttle, the higher the gear the more true it is. I can disk in 3rd gear/low range and have considerable control over ground speed without changing gears. I can mow in 7th (2/hi) and have come almost to a crawl (although rpms to the mower do drop) up to pretty much as fast a clip as I can maintain on my bumpy fields. So to suggest that a gear tractor requires a shift change ground speed is quite a misunderstanding of how they work.

 

[N80]

Pretty neat and simple concept.

It really is. And its just another one of those 'old timey' things that makes so much sense, costs nothing to implement, but is no longer used. To me it just defies explanation why this isn't on every basic tractor.

Granted, it would have limited value to most CUT users but it just couldn't cost much of anything.

 

[N80]

I also remeber a quite funny story about an hst ( kubota i think) trapped at the bottom of a gully that it's hst wouldn't crawl out of...

Soundguy

Was it due to the fluid sloshing down away from a pump or something?

 

[dmccarty]

I bite and enter The Great Debate.....

When looking to by a tractor, the JD 4700 gear tractor is/was 41.5 PTO HP and 40 for the HST. The HST was more expensive but I don't remember price.

I wanted to maximize the HP which was a good idea but I don't think I would see the difference HP wise between 40 and 41.5. I have run out of traction. I have run out of hydraulic power. But not PTO HP.

The PowerReverser is real nice. Another reason I bought the gear tractor over HST was that I drive manual tranny trucks and wanted them the tractor and truck to operate as similar as possible. The PowerReverser has a foot clutch but it also has a lever on the left side of the steering wheel that tells the tractor to go forward, backward or neutral. In neutral you can change geers as if the foot pedal was pressed. It works real well. Unforntunately after a long day of working on the tractor I have been known to get into the truck and move the turn signel lever to get the Ford to move forward.....

Its real easy to go forward and backward with a PowerReverser. Don't see how an HST could be that much better. I was mowing yesterday and much of the mowing was backing over heavy brush and saplings. Go backwards 6-12 feet with the MX 6 held high. Lower the MX 6 and move forward. Aim for a new spot. Repeat.

Using the FEL is the same. Never had a problem where I thought I was going too slow or too fast. I just set the geer and leave it there. The only time I think I needed HST or Crawler gears was when moving brick cubes. The pallet forks just barely would bit into the slots in the cubes. Maybe 1/4 inch clearance. Threading the slots had to be done just so which was hard since I could not quite see what was going on with the forks. Going real slow would have helped.

Knowing what I know now I would consider an HST but I don't know if I would buy it. It would get down to the extra cost.

Later,
Dan

 

[MossRoad]

It really is. And its just another one of those 'old timey' things that makes so much sense, costs nothing to implement, but is no longer used. To me it just defies explanation why this isn't on every basic tractor.

Granted, it would have limited value to most CUT users but it just couldn't cost much of anything.

I agree. It is just a printed ring. They have to print it anyway. And they have to stick it on anyway.

Now back to arguing...

Go drive a hydro!

 

[MossRoad]

I bite and enter The Great Debate.....

Oh, good! According to the drinking game, I was starting to sober up. Thanks!

 

[Soundguy]

Was it due to the fluid sloshing down away from a pump or something?

In that situation, i believe it was...

I have heard other stories of darwbar loads that simply caused the relief to open.. some without even spinning a tire.. etc.

soundguy

 

[N80]

Go drive a hydro!

I don't swing that way....

I will say this, we were considering a house in the country a while back (I live in the burbs now, my land is about 45 minutes south) and the place we looked at had a big yard, a small barn and some small pasture areas. It looked like the kind of place that a small tractor would have been perfect and if we had decided to move (it didn't work out for lots of reasons) I would have seriously considered a smaller HST tractor for that. It would have been perfect for general mowing, horse oriented chores, etc. And, my wife and daughter might have been willing to operate it more for the horse chores.

But I can't end a post without a parting shot, so I will mention that even my wife and 14 year old daughter can operate my primitive gear drive tractor. I really feel sorry for the boys my daughter will date, if they don't drive a truck and can't drive a stick she's going to give them heck.

 

[dynasim]

I am not really here to enter the HST/gear debate, but would like to enlighten the story about HST slippage(not being able to spin the wheels).

I was curious about the effect, which the HST goes into bypass, and the tractor fails to spin the tires. I have a the largest engine in the tractor class. It has been observed(causing annoyance)by some that in low gear, you can't make the engine stall on my tractor leading to the conclusion that it has a weak HST.

Through relatively rigorous testing(FEL poked into the side of a hill), I have come to the conclusion that you can make it stall. You just have to push the go pedal down far enough. Most reasonable people will simply push the pedal down a little way, and since the HST is in bypass, it doesn't do any good to go any further and stall the tractor. The deal is, when the tractor is at rated RPM's, you have to push it most of the way down, which isn't a comfortable feeling.

If my observations are true, the HST can put the same torque to the ground that a gear transmission(with the corresponding gear ratio, or ground speed).

I guess I will jump a little into the debate. For me, the ability to precisely position the tractor, make small incremental and predictable movements, hold a position on a hill, and safely start movement on steep slopes is critical to my safety and activities(I do most things without helpers). An HST is an order of magnitude better than a gear for these things. With a gear, you have to develop the art of transistioning between the brake and the clutch in order to do the things I would need to do safely and effectively. I grew up on a farm, collecting wood, loading feed, haying, tilling, installing engines, etc., all with gear tractors, some with powershift, so I have a basis for making a comparison.

I don't mow or pull ground engaging equipment, so my observation don't apply there.

Chris


P.S. I have used a tiller in rocky and rooty soil, and found it very useful to have immediate and total speed control.

 

[N80]

I was curious about the effect, which the HST goes into bypass, and the tractor fails to spin the tires. I have a the largest engine in the tractor class. It has been observed(causing annoyance)by some that in low gear, you can't make the engine stall on my tractor leading to the conclusion that it has a weak HST.

I would not have drawn that conclusion anyway. I would just assume that its designed to bypass before a stall. That seems like a reasonable design feature and does not indicate how much hp the tractor can apply in dynamic situations (i.e. not up against a hill).

If my observations are true, the HST can put the same torque to the ground that a gear transmission(with the corresponding gear ratio, or ground speed).

I don't see how those observations lead you to that conclusion. I'm not saying you are wrong, I just don't understand your reasoning. My reasoning that suggests that HST does rob you of some HP (draw bar) compared to a gear tranny might be wrong also but is based on several things. First, it has been mentioned that the HST generates a good bit of heat. That means less HP. How much? I have no idea. But I also remember reading, and experiencing, that an automatic tranny in a car or truck puts significantly less of the flywheel HP to the ground than a gear tranny. I'm assuming that loss is in both heat and in spinning/pushing transmission fluid, etc. I may be wrong about the reason but countless dyno tests published in magazines suggest that the effect is true. But that was during the days where a straight drive always got better mileage than an auto and that has obviously changed so the HP loss may be a thing of the past and it might not translate to an HST anyway.

But so far, two important facts remain. 1) No one has produced any test results to suggest that the drawbar HP would be the same or different yet....so we just don't know for sure and 2) If a Kubota L4400DT and a Kubota L4400HST (and comparable machines) cost the same thing, this would not be a big issue and would be a non-issue if someone could prove that drawbar HP was the same. But, they don't cost the same, and likely never will....and I'm not holding my breath regarding drawbar HP comparisons either. (Although there were some posts regarding some Ag based tests of some domestic CUTs but I don't know if there were any incidental gear vs HST reports).

And I suspect that if a dealer told me the DT and the HST put the same torque on the ground and cost the same, I'd give the HST a serious look. But I still wouldn't buy it because I want to be able to work on this thing in the future.

I guess I will jump a little into the debate. For me, the ability to precisely position the tractor, make small incremental and predictable movements, hold a position on a hill, and safely start movement on steep slopes is critical to my safety and activities (I do most things without helpers). An HST is an order of magnitude better than a gear for these things.

I will be told, and fairly so, that I have no basis for disagreeing with this statement since I have never spent any quality time with an HST, but I feel safe in challenging your 'order of magnitude'. I have never been in any situation, no matter how tight or precarious that I have been unable to make precise and predictable position changes, movements, and adjustments. I can start on any hill (on my hilly property), up or down, wet or dry, and hold position on same, with little or no effort and rarely even have to think about it. I spend lots of quality times on wet, muddy and rocky hills, in the woods, around the cabin often with loader full and or implements on the back. and So it just seems a bit preposterous so think that HST is that much better. How can this be? Either, I'm delusional, which is possible and in which case you guys should just humor me or I'm some sort of Zen master with a clutch and a gear shift, or maybe, just maybe, that when you spend enough time with manual transmission you just learn to make it do the things it can and is supposed to do. I think that's probably it, because I've never been a master of anything and having that insight proves I'm not delusional.(I hope!)

So, is HST any better at these things? I can't say since 1) No experience 2) zero problems with my gear tractor (which has no synch or shuttle shift). But I trust you guys that it might be some better, maybe even a lot (I don't know about a magnitude ), but if given the rather extreme positions I get my tractor into and out of with relative ease, it still seems unlikely to be worth the money to me.

With a gear, you have to develop the art of transistioning between the brake and the clutch in order to do the things I would need to do safely and effectively.

I guess when you've spent your entire life driving nothing but manuals, that art becomes second nature. I very honestly am almost never even aware of doing these things. The main time I do become aware is when my left knee begins to ache and that would undeniably be less of a problem with an HST!

I don't mow or pull ground engaging equipment, so my observation don't apply there.

Well, even if you had, some of these guys wouldn't accept your observations unless you'd been doing it for 15 years on both types, every day, uphill, in the snow, with no cab.

 

[dynasim]

"I don't see how those observations lead you to that conclusion. I'm not saying you are wrong, I just don't understand your reasoning."

Maximum torque applied to the ground=maximum engine torque*gear ratio

was my thought, but power bleed would lower the net torque available, so you likely have more sound reasoning.

However, it is likely that, for a give class(frame size) the designers would design the transmission choices and ratios to maximize(make equivelant) the running gear to a torque limitation. (Actually, I would make the HST with a higher allowable torque do to the inherent soft start of the system, but that is a different debate). If that is the case, the robbed power would simply make the tractor go slower.


I would not do the things I do with my tractor if de-clutching was necessary to start movement. Subjective observations(what I made) about things are inherently subject to questioning, but are equally easy to defend.

Chris

 

[DreaminGreen]

Quote N80; "Well, even if you had, some of these guys wouldn't accept your observations unless you'd been doing it for 15 years on both types, every day, uphill, in the snow, with no cab."

Would that be with R1,R3 or R4 tires ??????

 

[N80]

so you likely have more sound reasoning.

The moderators are probably going to ask you to leave now.

I would not do the things I do with my tractor if de-clutching was necessary to start movement. Subjective observations(what I made) about things are inherently subject to questioning, but are equally easy to defend.

Chris

True.

 

[MossRoad]

...

If my observations are true, the HST can put the same torque to the ground that a gear transmission(with the corresponding gear ratio, or ground speed).

...

I don't think it can. Gears are a direct connection from engine to tranny to range selector to differential to axles, etc...

On a hydro (at least on my IH) the engine turns a pump. The pump pushes fluid. That fluid turns a motor. That motor turns the range selector. Then it is the same as a gear from that point back. There is fluid that bypasses the motor and slips by the seals, etc... that's where the loss is.

Just look at the stats on a tractor's drawbar HP. If it has the same engine and one is gear and the other is hydro, the hydro will probably be less.

 

[N80]

Just look at the stats on a tractor's drawbar HP.

Kubota does not list them, nor do they submit to the Nebraska tests (I think only the large Ag tractors would qualify anyway). Does anyone else that makes CUTS list drawbar HP? I think, like most automakers they don't want to for marketing reasons. The tractor companies, that I've looked at anyway, don't even publish the RPMs at which max HP is achieved. Kubota lists 'net' and 'gross' engine HP, and I don't even know what that means. I don't recall seeing Kubota list torque figures, which seems to me would be more important than any other figure.

What I would really like to see, on every machine, is rear wheel torque-rpm curves. But we'll never see it.