How does an HST compare in pulling power with the same tractor and a gear trans?

[5030]

Either you apply full torque almost instantaneously ( clutch ) or it can be applied as needed to retain traction as with an HST.

I don't find that to be accurate but you are entitled to your opinion, just like I am.

 

[jyoutz]

I wanted a gear tractor and price had nothing to do with it. I like putting it in the gear I know works for whatever task I am doing and no need to change anything. I do not like the whine of HST. But that is just me. Most people probably do need HST and good for them. No issues whatsoever with that. If they are inexperienced or going to do a lot of loader work, then HST is the way to go.

Inexperience has nothing to do with this choice. I had a gear tractor for 21 years before buying a HST. The infinite speed options and ability to keep RPMs up while moving slowly is great for cutting and tilling. And loader work is much nicer with HST. Am I experienced enough to operate GST, yes. Did I choose that -no.

 

[LouNY]

My only hydrostat is my old F2000 front mower. My tractors are gear, the IH 574 has close to 7000 hours on it I've had it for 20 years and never put a clutch in it. Did it have one when I bought it who knows, looking at it I don't think it has been.
My Branson only has around 900 hours with not wet clutch issues. On the farm the IH Magnums are 5-9000 hours and never been split. The old 560 and 400 Farmalls have had one clutch each with well in excess of 10,000 hours on them. The IH 656's gear drives have who knows how many hours with no or one clutch. The Ford 8000 has close to 10,000 hours and has never been split. The 1086 could use a new TA and will get a clutch then. Of course the IH 656 Hydro has had one complete transmission exchange and that never felt as good as the original and only kasted a few years that tractor has been mostly parked for the 15 years.

Those of you that think a hydro is the best thing since sliced bread just keep on believing that, I'll stick with gears, thank you.

 

[DaBear3428]

If someone wants to buy a gear trans tractor because it’s cheaper and admits that as the reason I have no problem at all with that compromise. That’s how life works. But when someone buys a gear tractor be it’s cheaper and then starts trying to convince other people it’s better like they have already done themselves that’s when the argument starts. Unless you live in a country that still uses compact tractors for farming there’s not a single hood reason to buy gear trans compact tractor over a HST other than cost.

I admit i tend to look at the value (to me) of anything i buy, I do not care to convince anyone of what they need to spend their hard earned money on. IMO HSTs are great but they are not the only solution. there are some benefits to a geared shuttle CUT other that first cost, such as fuel efficiency, % of engine power to the ground, % of engine power to the PTO etc. i also like the fact that you select the gear, set the governor on a flat hay field and let it eat (i know there is the cruse control feature on some HSTs). is the HST better at a lot of things? yes it is, is it the best at all things? no it is not! As i will not harangue some one for their choice in a tractor I also will not accept someone haranguing me over how i spend my money.

My only interest is informing others of the facts and yes they are subjective (as are yours), also I do not feel the need to justify how i decide to spend my money, it is my money and i will smoke it if that is what makes me happy.

 

[jyoutz]

My only hydrostat is my old F2000 front mower. My tractors are gear, the IH 574 has close to 7000 hours on it I've had it for 20 years and never put a clutch in it. Did it have one when I bought it who knows, looking at it I don't think it has been.
My Branson only has around 900 hours with not wet clutch issues. On the farm the IH Magnums are 5-9000 hours and never been split. The old 560 and 400 Farmalls have had one clutch each with well in excess of 10,000 hours on them. The IH 656's gear drives have who knows how many hours with no or one clutch. The Ford 8000 has close to 10,000 hours and has never been split. The 1086 could use a new TA and will get a clutch then. Of course the IH 656 Hydro has had one complete transmission exchange and that never felt as good as the original and only kasted a few years that tractor has been mostly parked for the 15 years.

Those of you that think a hydro is the best thing since sliced bread just keep on believing that, I'll stick with gears, thank you.

HST has greatly improved since the manufacture of your old IH.

 

[LouNY]

So you say,
it's still a hydraulic pump driving a hydraulic motor.

 

[jyoutz]

So you say,
it's still a hydraulic pump driving a hydraulic motor.

Local dealers say they replace far more clutches than they do HST rebuilds.

 

[SPYDERLK]

HP is rarely a factor when trying to see how much something can drawbar pull. Weight and traction are. If HP is your limiting factor, you are in the wrong gear or range(HST).

I can spin all the tires in low range on a HST. A gear tractor can do the same. So two tractors, same weight, same tires, both capable of spinning tires....I fail to see how one will outpull the other. When you already cannot get ALL the power to the ground.....loosing a little due to HST losses is irrelevant.

When it matters is trying to pull something at a specific speed.....like trying to pull a disc at 6mph and up a slight hill. If you struggle to maintain speed with a HST, then the gear version of the same tractor WILL do better.

But the notion that a gear tractor can pull significantly more.....or in the case of the messicks video (which was terrible BTW) claiming that the gear can pull 50% more.

Sure, that may be true in high range....but who pulls in high range?

I pull a 3-14 plow with my HST MX5100. By that notion I should be able to pull a 4-14 or a 4-16 easily had I opted for the GST trans.

Absolutely. Weight is traction. Case closed? Well-l-l no when the development does not cover a common exception that is a norm for most of us. We have tractors equipped with loaders. We ballast and counterweight by necessity to improve the force application platform. This weight is more traction and more potential force ... if you can get requisite torque to the axles.

The feature of HST allowing infinite speed control from 0 to top speed of each range presents the possibility of "infinite"/huge wheel torque at creep speed in any range. Creeping speed requires so little of the engines power that the operator has no indication of the tremendous forces that may be being applied. Wisely, the HST designers include a relief valve between the output of the variable displacement pump and the hydraulic motor that drives the wheels through the range gears. So when the relief operates and the wheels wont turn you shift to a lower range. When the wheels wont turn in the lowest range that is the limit of motive force that the tractor will apply.

With a gear tractor the link between engine and wheels is fully mechanically defined. Engine speed and wheel speed are always directly proportional. There is no variable between engine and final drive that the operator can control. The engine feels wheel torque and the operator can gauge it by sound and gear down where needed. The hidden "infinite" torque possibility of a zero to xspeed is removed, so the automatic resetting "fuse" in the HST isnt needed. The wheel torque is limited by the gearbox amplification of clutch slip torque. Presumably the designers choose components with accommodating safety factors. Apparently so, at least in above creeper gearset reduction transmissions.

So, Which transmission on a comparably powered tractor will provide greater motive force (wheel torque/r) ? Absent a specially contrived test you can only find out by equipping the tractors with loaders and requisite counterweight and ballast for safety and prudence. Then use them on the high side of their loader capability. I think you will find as I have, that you will occasionally find the wheel torque limit of the HST tractor but never the one of the gear tractor. Indeed, the manual trans seems to spin wheels nonchalantly in 1st gear on loads it wont move.

 

[K5lwq]

Inexperience has nothing to do with this choice. I had a gear tractor for 21 years before buying a HST. The infinite speed options and ability to keep RPMs up while moving slowly is great for cutting and tilling. And loader work is much nicer with HST. Am I experienced enough to operate GST, yes. Did I choose that -no.

Not what I was implying. My point is that the learning curve will be less with HST for inexperienced people. Inexperienced people on a gear tractor are likely to abuse the clutch and may see failures more often. They also will not be able to select the correct gear for the task right away.

 

[MinnesotaEric]

Well, your second phrase pretty much confirms the first one about not knowing how to run a clutch, specially considering the compact tractors over there get hardly any hours per year, which won't tell much of the durability of an HST either. Heck, I have yet to see an HST tractor with over 3000 hours that hasn't been worked on the HST at one point or another.

There seems to be this misconception that clutches are replaced as frequently as one replaces a filter or something silly like that. That's simply yet another case of misinformation sent towards the geared transmissions. Around here, a clutch will easily last over 3000 or 4000 hours, more in most cases and that's doing some hard work like pulling discs, trailers, plows, etc. Actually working the tractors.

Just keep in mind that a simple HST repair can cost a lot more than a simple clutch job and that's if there is actually parts to fix as it's not uncommon for them to only sell new HST units.

He tells a mechanic.

Why are you assuming:

People who like HSTs don't know how to run a clutch?

Or a power shuttle?

3-or 4,000 hours?

But these are little machines. HST commercial lawn mowers get sold with 2,000 or 3,000 hours because after that they start needing more maintenance. The HSTs in the smallest tractors are comparable to ZT5400 drives, but generally don't rack up the hours in the same time frame because they aren't used in daily production commercially. Larger HST transmissions are expected to last as long as the transmissions themselves by fleet managers with in-frame engine rebuilds going from 8-12,000 hours.

Regular maintenance, pin wear, improper storage, and harsh operators are the biggest contributors to premature failure.