Hydro vs Standard Shift?

roberts · Aug 14, 2003

All else being equal what about the noise factor? Sometimes when my son is doing loader work close by I can bearly hear the engine. Not so with the Hydro

slowrev · Aug 14, 2003

What kind of tractor is he using that has that noisey of a transmission ? But then again it is better than the Smokey Mtn Man dillema. Remember....

JerryG · Aug 14, 2003

We all have different strange things about use. Maybe one of mine is that I am not going to own a tractor that you have to run at near full throttle all of the time and listen to the noise. I do understand why several times member here have talked about hearing protection. That is one of the reasons that I won't own a hydro.

Typhoon · Aug 14, 2003

I run my TC29 at low throttle all the time and its hydro. I consider my tractor to be very quiet for the most part. But like you said, everyone is different and has different items that they consider to be most important. I have been bucking and limbing trees and pulling them out of the woods, (being in very tight spots, on steep inclines, in mud, etc) and the hydro has saved my butt many times. I actually have more experience with gear tractors (its what my dad had) and they have their strong points too, but for maintaining my 50 acres, the hydro reigns champion in every catagory. Again, just my opinion. And I don't have to run mine at high rpm's at all. I run at high rpm's when doing loader work, or when mowing, or pulling a heavy load. But just getting from point A to point B, I run it at low rpm's all the time. And my transmission is virtually silent. You cannot hear it unless you listen very close.
Good luck! /forums/images/graemlins/grin.gif

Soundguy · Aug 15, 2003

( Well, thats perhaps is more speculation on your part, my local dealers would argue with you to a considerable degree about the durability issue. The hydrostatics have been found to be very durable )

Given that a hydrostatic drive is just packed full of seals and o-rings... I can't see how they can stand end to end in durability over time. Take a 50 year old geard tractor up against a 50 year old hydrostat.. I think you would find a higher 'death rate of the hydrostats, after 'x' years. Deffinately speculation on my part... but is a hadged guess. What is the oldest hydrostat tractor we have to compair to? a cub from the 70's? hard to establish good numbers there, when people have 1939 9N's banging around on original trannies, and input shaft seals.... 65 years and going... In the short term.. i agree that the hydrostat is going to be an even contender, except possibly in ground engaging implimints, and a few select other areas... but i think as you add time as a factor... I think the mortality rate of the materials involved will peak out higher than the gear units...
Another point about that is operation vs. good operation. A 60 year old gear tranny with a shot input shaft seal will leak like a seave.. but if ya keep dumping the oil in every day.. the tractor chugs right along.... let a handfull of seals/ orings fail in a hydrostat, and i imagine the tractor wouldn't be able to move... etc. Again.. not bashing the hydros...

Soundguy

Soundguy · Aug 15, 2003

( the winner hands down in my book, for ALL applications,)

I simply think that is incorrect.. I don't think we have the technology yet that will allow for the same level of power transfer and extremely low loss ratio of gear to gear, as a coupling, as opposed to a fluid coupled drive... there just has to be more loss in that system at our present level of hyd technology. Given two identical tractors, edentical engines, rpms, etc.. The Gear model has to transmit more power to the ground impliment than a hydro can.. simple math... I don;t agree with 'all' applications. Seems to mee that lugging a plow up and down a pasture for xx hours is gonna build some decent heat inthat hydrostat, that otherwise wouldn't be present iont he gear tranny..... again, has too.. that energy loss in the fluid coupling goes somewhere...( is turned into heat ).

Soundguy

DKinWA · Aug 15, 2003

Rat-

"picking the fly poop out of the pepper"

My wife thought that was hilarious /forums/images/graemlins/laugh.gif Getting back to tractors, I really don't think either transmission really has anything over the other. As much as I like my gear tractor, I wouldn't write off a hydro if I went tractor shopping tomorrow.

stvman · Aug 15, 2003

I think the area of the country you are in makes a big diffrence in long term value of a tractor. I can only speak for the northeast but hydros here sell easily 4 to 1 over gear at most of the dealers I talk to. Some will not even take a gear in trade.

I wish I preferred gear I like to save money. But for me there is no comparison I would gladly put 1000.00 a year in the bank over the life of the tractor to pay for any potential problem for the privelage of having hydro.

As far as complexety and o-rings failing over time My dad has a 16 year old Toyota van with an automatic trans 475,000 miles, never touched still going strong. If I had to place a wager on the future my money would be on hydro. Steve...

_RaT_ · Aug 15, 2003

If we read all the comments Jerry we will find that you don't have to run a hydro at full RPM, no, no more then a gear tractor. Is there any reason this is so hard to understand as it seems to be mentioned quite often? I run mine at 1700 to 1800 RPM for most uses like many others except when mowing, then its about 50 to 100 RPM less then full 540 PTO RPM. When you mow with a gear tractor and mow, its running at the same RPM to acheive the same PTO RPM. Is this a common thought that hydros are run at full or near full throttle? Curious, nothing could be further from the truth. My experience is that I can operate it at the same RPM as my gear tractor. The higher the engine RPM the faster I go and if using the PTO, the faster it goes. At about 2000 RPM, I'm at the peak of the torque curve. Attempting to straighten out the misunderstandings, but it's not easy here. Rat.... /forums/images/graemlins/smirk.gif

MossRoad · Aug 15, 2003

Some Hydro's have been known to suck air and quit pulling on certain grades of slopes 

So have some engines, starving them of oil lubrication. It is important to know the operating limits of a machine before using it. /forums/images/graemlins/smile.gif

slowrev · Aug 15, 2003

Agreed, it's just that the gear trannies do not have this limitation.

MossRoad · Aug 15, 2003

All else being equal what about the noise factor? 

Some HSTs have a hydrostatic whine. Both of mine do and I find it quite pleasent. It is not loud or annoying. Just the sound of a different piece of machinery. I can't hear it when the mower or brushhogs are running, but can when doing loader work.

MossRoad · Aug 15, 2003

Most HST tractors need to be run at high throttle all of the time. This provides pressure to the driveline and hydraulics and also provides proper lubrication.


OK, I'll recant my statement since several people have commented that they don't run their HST at high throttle most of the time. I'll change MOST to BOTH OF MY until I hear otherwise. Sorry for any bad information that I may have given. /forums/images/graemlins/blush.gif

But I would still like to hear what the operator's manuals for several brands of HST say about operating RPMs please. Again, thanks in advance.

kensfarm · Aug 15, 2003

I think it's time to have the "First Annual Tractor Olympics"!

MossRoad · Aug 15, 2003

I think it's time to have the "First Annual Tractor Olympics"! 

Wouldn't that be fun. Take the same tractor with the same engine, but a GEAR and a HST and put them to work. Use the same operator and the same tasks.

What events would you folks like to see? Here's a few.

FEL in loose material from point A to point B.
FEL in hard soil from point A to point B.
Mowing
Brush hogging
Field plowing

And don't forget the obstacle course! /forums/images/graemlins/cool.gif

kensfarm · Aug 15, 2003

It would be interesting to see a farm covered w/ CUTS like ants on a ant hill.. and the farmer who hosted the event would get all his farm work done in a weekend!

cowboydoc · Aug 15, 2003

Attempting to straighten out the misunderstandings, but it's not easy here

It's not easy because everything is speculation and personal bias and opinion. Things are stated as fact when they are not. It's opinion that you can run your tractor at lower rpms but the manual and other owners disagree. That's why there is never going to be consensus on any of this. Just state your opinion and move on. You are not anymore right or wrong than anyone else on this issue. What works for you doesn't necessarily work for someone else. It's an individual choice and one is not anymore right or wrong than the other.

KiotiDK35 · Aug 15, 2003

Very well put Richard.

fivestring · Aug 15, 2003

And move to a different farm everyday!!! /forums/images/graemlins/grin.gif

MossRoad · Aug 15, 2003

DISCLAIMER: I'm not trying to beat a dead horse here, just provide some information for all of us to share. If anyone has something similar in their owner's manuals, please provide it as I'm just curious by nature as to other machines and such. I really enjoy learning new things. Thanks.

Here's what it says in my operator's manual:

This is for a late '70s International Harvestor 2500B. It is a 50PTO HP 4 cylinder gas engine tractor/loader with HST. Some came with backhoes, mine came with a 3PT hitch with draft and position control and independant PTO.

This is from page 22 if you care to read along, if you have the book, of course /forums/images/graemlins/tongue.gif .

"Greatest efficiency of entire tractor, loader, and backhoe is at 2000 engine RPM and up, depending on desired speed of tools... the tractor forward and reverse travel speeds are controlled by range movement of the foot pedals or the Remote Drive Control Lever.

When pedal is not depressed, the transmission is in a locked or braked position.

Maximum torque and slowest travel speed is obtained with the least downward movement of the pedal.

Example: The least possible depression of the pedals will give you the slowest speed with the greatest torque to the drive wheels for digging or crowding into the stock pile or bank.

Using the tractor brakes is rarely required because:

As your foot moves upward from the hydrostatic pedal you are automatically decelerating your travel speed... and when your foot moves completely off the pedal, the pedal returns to the neutral or lock-up position and automatically brakes your transmission and travel."

It goes on on the next page to read:

"The hydrostatic transmission is designed so that: In high range the travel speed deceleration is less abrupt(slower) and the braking is more cushioned to prevent abrupt automatic braking."

"The cushioned braking and travel speed deceleration is timed with the automatic pedal return(or full-up position)

This definite time differential is designed into the system to not only provide the travel speed deceleration and cushioned stop but prevents accidental reversal of direction by the operator."

This is the part about the engine providing control at all times, which would include braking.

"The operator accustomed to mechanical or torque converter equipped tractor may be in the habit of reducing the engine speed for more positive control when operating in close quarters. This is neither necessary nor desirable with the hydrostatic tractor because the higher engine RPM will provide more positive control of not only the hydraulic tools but also the travel speed and automatic deceleration and braking. Maximum performance and control is achieved with high engine speed."

So, this is where I got my impression that the HST should be run at higher RPMS most of the time. Hope this helps /forums/images/graemlins/smile.gif