Kubota L3901 4X4 HST VS GST Transmission

[k0ua]

Of course I am explaining basic operation here.. there is always more, And Hydrostat + has a lot more. But first things first. Now you have the basic ideas of how to operate the system.. Now lets talk about ranges.. Remember I said the range selector was like a gear shift behind the hydraulic motor? Well that is what it is. Does it make sense that you will have more torque and less top speed in Low range, and medium torque and medium speed in Medium range? And low torque and High speed in High range?.. Just like a gear transmission right?
Within each range you still have infinite speed control in both directions up to the maximum speed the tractor will go in that range. Make sense?

 

[Sprinklerman]

Both my kubota and my new hollands are HST machines . I passed up some good deals on gear machines , I have run them before . They were ok , but I do landscaping , snow removal , grading and general maintenance . I dont farm with mine . I waited and found a good used HST .

 

[k0ua]

Both my kubota and my new hollands are HST machines . I passed up some good deals on gear machines , I have run them before . They were ok , but I do landscaping , snow removal , grading and general maintenance . I dont farm with mine . I waited and found a good used HST .

Hard to beat an HST for the kind of work you do. If I was plowing 40 Acres, I would want a good Gear machine. But for what you mentioned.. it is HST all the way.

 

[Sprinklerman]

Hard to beat an HST for the kind of work you do. If I was plowing 40 Acres, I would want a good Gear machine. But for what you mentioned.. it is HST all the way.

I would love to have 40 acres , I have 7 acres 1/2 wooded 1/2 cleared about 10 miles from my house , use to be a strawberry farm . I would like to plant it with something , but all I think I would be doing is feeding the deer

 

[FTG-05]

Of course I am explaining basic operation here.. there is always more, And Hydrostat + has a lot more. But first things first. Now you have the basic ideas of how to operate the system.. Now lets talk about ranges.. Remember I said the range selector was like a gear shift behind the hydraulic motor? Well that is what it is. Does it make sense that you will have more torque and less top speed in Low range, and medium torque and medium speed in Medium range? And low torque and High speed in High range?.. Just like a gear transmission right?
Within each range you still have infinite speed control in both directions up to the maximum speed the tractor will go in that range. Make sense?

You're doing great, thank you!

 

[David_Kb7uns]

keep in mind that the hydrostatic system is infinitely variable ground speed for a given input speed from the engine within the range of possible speed. Unlike an automatic transmission in a truck which has a finite number of gear ranges that are selected by clutch packs. If you want to go exactly 2.1280763 miles per hour, you can do that with a hydro while lets say your engine is turning 2000 RPM. Now with the exact same engine RPM of 2000 you can adjust the swash plate angle to now make the tractor go 1.928503 miles per hour. and if you want to change direction and go in reverse at 1.928503 miles per hour you just change the swash plate angle the other direction passing through the neutral position to make the hydraulic motor run in the other direction because the flow direction of the fluid is reversed. With an automatic transmission in a truck, you cannot go 1.928503 miles per hour and 2.1280763 miles per hour with a fixed engine speed of 2000 RPM. The speed in the automatic transmission are fixed for each given RPM and each gear the transmission is in. The GST transmission is actually closer to the automatic in your car or truck than the Hydrostatic transmission is.

I will differ with you on the GST being close to an automatic in a car. A normal modern car automatic has a torque converter along with clutch packs and bands for the planetary gear sets.

The GST has a valve body that shifts gears with forks controlled by hydraulic cylinders controlled with electric servo valves. This will give you many combinations in a compact area because their is no stick involved along with the hardware. The front end of GST tranny has a normal dry clutch which never gets used except in an emergency and the Forward and Reverse is done with wet multi disk clutch packs.

David Kb7uns

 

[David_Kb7uns]

So from assumption this means that the range selector can be shifted while not completely stopped like the Grand L's and the gear selection will have to be stopped. Next time I stop by my dealer I'll check this out.

Usually range is always stopped and gears can be synchronized or not. The way I read it in the brochure is only the shuttle gears for F and W can be shifted while moving. I may be wrong but I say test drive it.

The economy or standard Ls are basic tractors kind of like the old days. The Grand Ls are a whole different story. They have heavier axles, larger loaders and a heavy duty drive train. The 3 point has 2 external lift cylinders, hydrostatic steering, isolated work platform, Intellipanel larger hydraulic pumps and so on. Look each over carefully the difference is not just fluffy options.

David Kb7uns

 

[FTG-05]

Ok, sorry for another dumb question: What's a "Grand L"?

Thanks,

 

[boyt]

I have a hst grand l love it fast lots of power never had a problem and I plow snow with mine I would recommend it highly

 

[k0ua]

Ok, sorry for another dumb question: What's a "Grand L"?

Thanks,

You own one. The standard "L's" are the actually economy line of the L's and the Grand L's are the deluxe line of tractors in the Kubota L series. An example would be your L4330, that would be a Grand L, an example of a Standard L would be an L2800, L3400, L3200, L3800, and now L3301 and L3901.