HST Ground EngagagementM

[SCDolphin]

I have looked at the orange tractors with hst and JD's. I have about 15 Acres I need to disc up and pull a bottom plow now and then. I have a need for hst. Some JD dealers told me that their hst was not built for ground enagagement. What's up with that. Does orange have a tougher hst???

 

[MDM]

What model of tractor are you referring to? Some will pull better than others. I just did a little plowing a couple of days ago. I pulled a 16" one bottom plow with ease with my L2800HST. A 30 hp hst machine will not have the pulling power of a 30hp geared tractor of identical design and weight. Is that what you are asking. If all you are going to be doing with your tractor is pulling ground engaging implements, then get a geared tractor. If you will be doing a little plowing here and there plus a lot of other various tasks, then consider a HST. You just have to get the right sized tractor for your needs. I doubt that a Kubota or Deere HST tranny would be any more reliable than the other. The dealer probably meant that geared tranny would be better than HST for pulling a plow. There are far more knowledgeable here than me, and I'm sure they will weigh in.

 

[john_bud]

I have looked at the orange tractors with hst and JD's. I have about 15 Acres I need to disc up and pull a bottom plow now and then. I have a need for hst. Some JD dealers told me that their hst was not built for ground enagagement. What's up with that. Does orange have a tougher hst???

Well, I didn't think so, but I guess the K HST is tougher than the JD HST.

(That, or the sales person you spoke to is ill informed.)



I use my K L3410 HST with a 2x14 bottom plow, tiller, box blade, etc. No problems. It probably has 10% loss in draw bar HP compared to a gear tractor. I'm ok giving that up as it's not a primary tillage machine. If you want a JD, you may want to speak to a different dealer for a second opinion or even email JD direct and ask for clarification of your sales persons statement.

I drive orange, but green tractors are good (just picked too soon).

jb

 

[Z-Michigan]

See my post to your identical question in the JD forum. There should be no difference between those two brands or any other HST from a quality manufacturer. All can be used for a moderate amount of plowing, just not a good choice for 10+ acres (arbitrary cutoff).

 

[SCDolphin]

On Kubota looking at L5240 or JD in equiv. horse power. I like the M tractors but my knee won't hold up to clutching. I have about 15 acres I would like to be able to disc up and plant.

Thanks

 

[Z-Michigan]

That's a fair bit of land work. Have you considered a Kubota L series with "glideshift" transmission (GST)? The GST is basically a gear transmission (12 forward, 8 reverse) with a powershift system. There is a clutch pedal but my understanding is that you don't use it while operating - I think it may be just a safety feature like the clutch pedal on their HST models is. The GST also includes a left hand shuttle lever and a hydraulic clutch. Pretty cool setup all in all. The GST would be better for that amount of ground engaging work than HST, and really doesn't have any downside unless you just HAVE to be able to go precisely 2.34534589 mph at exactly PTO rpm (which an HST can theoretically do). Having said all that, HST on a tractor the size of an L5240 or JD 4520 should be capable of doing your ground engaging work.

 

[AceDeuce]

A 30 hp hst machine will not have the pulling power of a 30hp geared tractor of identical design and weight.

In theory that would only be true at the same forward speed (due to the lower mechanical efficiency of an HST). However, the obvious benefit of the HST is it's infinitely variable speed. The slower you go, the more torque it delivers. That implies that, even with the additional losses, an HST equipped tractor should be able to generate higher maximum pulling force at the drawbar than a gear-driven machine - just at a slower speed.

I realize the above statement is based on a narrow set of parameters and is only true in the theoretical world. I couldn't tell you what happens in real life because I am far from an authority on the matter.

I would tend to agree though, in practice a GST would be a better option for ground engaging applications. HST was designed for the kinds of uses that a compact utility tractor will see - involving frequent speed and direction changes. A GST is excellent at constant speeds moving continuously forward.

 

[psdx]

The last post is exactly right, but to clarify a bit...

The available hp from a HST tractor is less than a comparable tractor with a mechanical gear transmission. This fact is evident by the PTO hp ratings for any given tractor that is available with both transmissions. Therefore, less available hp means less drawbar hp. To get the same PTO or drawbar horspower with a HST transmission you need to buy slightly more engine horsepower. To me the convenience is worth it, but others may value the savings (of requiring less hp) from using a grear driven transmission over the convenience of a HST.

 

[john_bud]

The last post is exactly right, but to clarify a bit...

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And a further clarification - you do field work at the fastest possible speed that gives you the result you need, so slowing down to get more torque is possible, but not practicle when you are trying to make $$.

Also, most tillage equipment works better as you increase the speed. Too slow and a turning plow won't turn the earth over.

jb