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

[oosik]

Hmmm ....... I just wonder. A "newbie" who has never been near a tractor. Does he REALLY have the knowledge to figure out which transmission will be best for his situation. Both my tractors have/had standard gear shift transmissions. Up until I bought the Taco Wagon all my vehicles have been gear shift. My first tractor - Ford 1700 4WD - was gear shift. Mainly because I was most familiar with this type of setup.

 

[Cougsfan]

One advantage a geared tractor has, and if it has been said, I missed it. On a geared tractor; a certain gear at a certain engine speed gives you a constant ground speed. Not so with a hydro. For weed spraying where constant ground speed control is important, that can be an issue. Especially on hills. Few hydrostatic tractors (if any) have speedometers. I spray with a hydrostatic, so I use a automobile gps to tell me my ground speed. That helps immensely, but I still have to constantly jocky the throttle to maintain a constant speed (even with it's "cruise control"). This is a little off topic cause it has nothing to do with pulling power, but it does have to do with hydro vs gears.

 

[4570Man]

No, you just prefer the ease and convenience of a hydro. No shame in that.

I guarantee you’ll have more hand work to do after you get done with the gear jammer. There’s a reason virtually every precision equipment is hydraulic vs gears. And a 1900s tech gear trans was the comparison here not a good one.

 

[crashz]

My L2501 is the first HST tractor I have owned. Love the precision, the speed, the ease and the smoothness. But I miss the power of my little JD 770. I do no ground engaging work, but have mowed with both, and the 770 would barely slow in the deepest, thickest stuff. The L2501 needs to slow up.

When doing loader work, the L2501 is hands down easier. But I could dig and load pretty well with the 770. Just needed a little rhythm.

One thing I notice I do less is spin the tires. The 770 only slowed down when it broke traction. And on a light tractor, that happens a lot.

 

[Edward Romero]

One thing I haven’t read is when you’re working on a slope the gear drive will lock your wheels when you have to stop your tractor along with a parking break. An HST does not hold you on a slope and you have to rely on solely the parking break. Really helps if your parking on the hill and leaving your seat a lot like me having to pick up rocks to clear the land for mowing. Mine a Kubota MX5400DT. It has a Shuttle Shift and I find extremely easy to use. And besides as a person who been using a clutch since 12 years old it’s all second nature. Besides with the HST your losing all the fun. I’m extremely happy with the gear drive and saved $2,000. And with HST users you cant miss the power disadvantage if you never worked with the same tractor with a gear drive. And tractors are loud enough without adding that annoying whine of an HST.

 

[npalen]

So what is the difference between the two regarding the parking brake?

 

[4570Man]

So what is the difference between the two regarding the parking brake?

I don’t see how you could consider working on a hill an advantage with a gear trans. A gear trans has zero holding power when it’s in neutral. Meaning while you’re changing directions or sitting with the engine running it’s all brakes holding. Also when you change directions you have to hold the brake and feather the clutch. Compared to the HST where you just have to push the pedal. You have to set the parking brake when you leave the HST because it will creep a little bit.

 

[Edward Romero]

This conversation is entertaining but the two tractor drive technologies were designed for different purposes. The hydrostatic transmission allows better close quarter control. You set the engine RPM on a diesel engine and the governor adjusts the fuel delivery based on load to maintain the same RPM. So saying a gear transmission tractor can idle up a hill, the governor is increasing the fuel as the incline increases. Now on the hydrosatic transmission, you can set the engine RPM and the operator is controlling a fluid flow. The benefit of the hydrostatic drive is that you can maintain the engine RPM in the sweet spot of torque while the operator adjust speed. Mowing a lawn or using a loader, the HST shines while you have to constantly slip a clutch on a GST. As for which pulls better, given a fixed load and both spinning tires, they should be equal. If you want to know which will pull more of a load with the same HP, the gear drive will. Time is also a factor, pulling a heavy load with a HST builds heat and you lose more efficiency.

Construction equipment use hydrostatic because besides the drive system, there are a lot of other hydraulic functions on the vehicle as well As for the large tractors, the premium ones use CVT transmission to get the benefits of the hydrostatic with less power loss.

On my Kubota MX5400DT you don’t slip the clutch ever. Let the clutch out in any gear with out giving more throttle and she goes. Driving a 10 speed bus you do not slip the clutch like you would with a gas rig. Maybe on a gas tractor you might have to but only drove diesel tractors

 

[Edward Romero]

I don’t see how you could consider working on a hill an advantage with a gear trans. A gear trans has zero holding power when it’s in neutral. Meaning while you’re changing directions or sitting with the engine running it’s all brakes holding. Also when you change directions you have to hold the brake and feather the clutch. Compared to the HST where you just have to push the pedal. You have to set the parking brake when you leave the HST because it will creep a little bit.

Put the tractor in gear, kill the engine and she won’t move. My tractor will start up that hill in any of the lower 4 gears and you do not slip the clutch. On a HST kill the engine and put it in gear and it has no holding ability for the wheels. It’s a diesel maybe in a gas tractor you might need to slip it slightly.

 

[MinnesotaEric]

For loader work, the HST is the way to go. For snowblowers, I also think the HST is the way to go as the HST can keep the blower's rpm up under varying loads easier than a gear tractor.

Anyway, one of my popular videos discusses HST verses gear transmission.