How to drive Kubota L3430 HST Uphill

[Komrade]

Hello Forum.
I am absolutely new to tractors.
I've recently purchased a slightly used (550h) 2008 Kubota L3430 HST with BH9000 Backhoe and a 72" FEL (and a meyers snow plow) to maintain a property on a relatively steep bank of a river.

We unloaded the tractor at the bottom of the hill, as it was middle of the night, and it would be difficult to turn around with a 30' trailer.

I had to take the FEL home first, and come back for the plow. As I climbed up the hill I seemed to lose speed and RPMs no matter how hard I pressed forward, or how high I raised the RPMs. That seemed to be the case in both "L" and "M".
The grade of the hill is around 20%.

I've read elsewhere on this forum that it's a "common" problem with these tractors, due to the early version of the HST transmission. However, no one really talked on how to properly drive this tractor.

Any hints or links would be greatly appreciated..

 

[jeff9366]

You are fortunate to have a low hour Kubota L3430 as your first tractor.

I have an L3560 HST, your tractor's direct descendent, as my third tractor, my second Kubota HST tractor.

HST transmissions deliver max torque at low ground speed. Therefore your HST has three primary ranges so you can move over the ground at varying speeds.

[In addition, your L3430 may have a HST+ feature offering two HST sub-ranges within each HST primary range via a two-position wand shift on the steering column.] ***

Your Operator's Manual will have a page showing speed over the ground in each of the three HST primary ranges and three sub-ranges, selected by the two-position wand shift on the steering column.

Max speed in each HST+ range on my L3560 are:
HST+(1) LOW = 2.1 mph, MED = 4.3 mph, HIGH = 09.9 mph. ***
HST+(2) LOW = 3.5 mph, MED = 7.1 mph, HIGH = 16.4 mph.

*** My guess is HST remained in HST+(1) sub-range while HST primary range was shifted between LOW and MEDIUM.

Did you have Four-Wheel-Drive engaged as you went up hill?

You do not have an 'early version' of the HST transmission.

Johnson City Kubota & Equipment, LLC​

"Hydrostatic Drive". There is nothing new-fangled about this transmission. It has been around for a long time. Nevertheless, it is among the least understood of all transmission types. It is common for it to be compared with the automatic transmission in an automobile. They are different animals altogether. The only similarity is that they both use oil to transmit power. Tech types describe a hydrostatic transmission as being a variable-displacement hydraulic pump, driving a fixed-displacement hydraulic motor. Now, to the un-initiated, that's a bunch of gobblety-gook. So let's s t r e t c h that explanation out a little bit. Any hydraulic pump's sole purpose in life is to deliver some amount (volume) of fluid to some other device, which in turn moves whatever is attached to that device, causing work to be performed. This can be either through linear motion (as in a hydraulic cylinder), or rotary motion (as in a hydraulic motor). If we want to control how quickly our gizmo moves (or rotates), one way we can do that is to vary the amount of oil that the pump sends to it. If our pump is delivering four gallons a minute, things will happen four times faster than if we only pump one gallon a minute. Since we can control our pump's output, we can control the motor's speed. Now, unless we just want to go around in a circle all day long, we've got to figure out how to change directions. No problem. Most hydraulic motors don't care whether they are turned clock-wise or counter-clockwise. Since a hydrostatic transmission operates in what is called a "closed loop" system, consisting of the pump and motor units, we simply reverse the direction of flow from the pump, causing the motor to operate in the opposite direction. Oh, by the way, "closed loop" means that a fixed amount of system oil can be considered as trapped, or contained, within the pump/motor circuit. Assume that a certain hydro transmission is of a size that it contains 500 ml of oil within the closed loop. That volume remains constant, never changing regardless of tractor speed or direction. So, for any change that we make in the output volume and/or direction of flow of oil from the pump section, a reaction must occur in the motor section, inducing a corresponding change in motor speed and/or direction. In reality, there is a certain amount of oil that is constantly escaping from and being replenished back into the closed loop section of the transmission. This is because a small amount of oil is allowed to flow all around the various components for lubrication and cooling purposes. The greatest advantage of a hydrostatic transmission is the ability to infinitely vary the ground speed, and quickly change directions. It's like having a million speed transmission. If you need a travel speed of 1.200589 MPH, it is available. Another advantage is reliability. This transmission is, by way of design, pretty much self-protecting from operator abuse. Also, on foot pedal controlled transmissions, there is a built in safety factor in that you need only lift your foot from the pedal, to bring the tractor to a controlled stop. The only disadvantage of note is a slight loss of power at the PTO shaft. You must also remember to apply the parking brake should you park the tractor on a slope. Hydrostatic is, by far, the best choice for turf mowing applications or for any tasks that require constant speed and direction changes within a small area. Loader work is another area where hydrostatic is a great choice.


LINK:

http://www.tractorbynet.com/forums/...5995-hydrostatic-transmission-hilly-land.html

 

[jeff9366]

Keep auditing T-B-N and you will soon be a tractor operating genius.

 

[nybirdman]

Or the short version:the more you press the pedal on the floor the "less" power/speed you have.Turn up the RPM"S and use less pedal for more hill climbing /power.

 

[The Fred]

Oh boy

Fred

 

[TripleR]

Many if not most people who are first exposed to an HST tractor are surprised at how high RPM they need to get good performance, I know I was when I got my L5030 HSTC.

 

[jeff9366]

Hello Forum.

I am absolutely new to tractors.

No one instructed me how to properly drive this tractor.

Or the short version: the more you press the pedal on the floor the "less" power/speed you have. Turn up the RPM'S, using the hand throttle, and use less pedal for more hill climbing /power.

i.e.: Use the hand throttle to increase engine revolutions.

 

[art]

Just another side, with hydro's brakes are not used as much as on gear drive tractors and often go thousands of hours with out needing to be repaired even on hilly ground. The life span is often two or more times the life of on gear drives if they ever need to be replaced but there is a catch!
They still do need lubrication as well as some action of work to keep them free!!!! We often find that with tractors five to ten year old and more that the brakes will stick in partial on position giving you the same conditions that you had with power.

 

[The Fred]

the same conditions that you had with power.


Power? What power? I think that's the problem, the poor gentleman has no power.

Fred

 

[Komrade]

Did you have Four-Wheel-Drive engaged as you went up hill?

Yes I did. I was told to always have it engaged on hills. Manual says so as well.

Also, I do not have HST+ (no shift lever)

Will try to find a balance to it. Didn't have a chance to play with speed this weekend.

 

[rswyan]

the same conditions that you had with power.


Power? What power? I think that's the problem, the poor gentleman has no power.

Fred

... lol ...

 

[boggen]

the HST, automatically "down shifts" like in an automatic transmission in a car or truck in a sense. when going up hills. this your MPH begin to drop off rapidly.

if you had a pure manual gear transmission, you would of needed to change to lower gears as you went up the hill as well.

ya need to remember tractors are not built for speed demons on the highway. they are setup so they produce Torque vs MPH.... a car or like is setup for less torque and more MPH.

 

[joshuabardwell]

Think of the HST as if it was a continuously variable transmission. The engine is running at constant speed. As you press down on the pedal, the transmission "shifts" to higher gears. What this means is that when you press the pedal just a little bit, you have lots of torque and low speed. When you press the pedal down all the way, you have little torque and high speed. What this means is that if you are going up a hill and start losing power, the correct response is to let the pedal up, not push it down. Imagine you were driving a manual shift car and going up a hill and started losing speed. You wouldn't shift to a higher gear. You would shift to a lower gear. That's what letting up the pedal on the HST does.

If your tractor has gear ranges, that also affects your torque. So, for example, in "high" range, you may not have enough torque to get up the hill, even if you barely touch the pedal.

Final thought: HST runs best at high RPMs. So don't be afraid to throttle up the engine close to the rated PTO RPM. On my tractor, that's something like 2200 or thereabouts. I don't always put it full up to 2200 if I'm just tooling around, but any time I'm actually working, it's running at 2200.

 

[hawkeye08]

Short answer, keep rpms up, less pedal is more power, shift lever in low, make sure brakes are not on (especially parking brake lock)...

 

[joshuabardwell]

Short answer, keep rpms up, less pedal is more power, shift lever in low, make sure brakes are not on (especially parking brake lock)...

tl;dr - More RPM. Less pedal. No Brake.

 

[jeff9366]

I was told to always have it engaged on hills. Manual says so as well.

Have you found the page in your Operator's Manual that specs max speed in each of three HST gear ranges?

You need to reply to your correspondents.

 

[Komrade]

Some links on tractor stalling on hills

http://www.tractorbynet.com/forums/...92651-kubota-l3430-hst-specifications-bh.html

Once and awhile I sense it could benefit from a touch more horsepower. Usually this is driving down the road in high gear and noticing the tractor can't stay at speed when going up a grade. I learned to use the cruise lever to drop off the speed a little to keep the RPM up. On that same grade, just keeping the foot to the floor (on the hydrostat pedal) will result in the tractor trying to stall out.

http://www.tractorbynet.com/forums/kubota-buying-pricing/70266-new-l3430-hstc-3.html#post791344

I have hilly terrain and low or medium range works best for driving up hills because the tractor tries to stall if I attempt to climb hills in high range

http://www.tractorbynet.com/forums/kubota-buying-pricing/114792-used-l-3430-hst-vs.html#post1320243

If I keep my hydrostat to the floor, I will stall the tractor as the grade increases. I am curious if the new one does this too

Note: Seems to be expected based on comments..

Going to go get the manual now.

 

[Komrade]

Just another side, with hydro's brakes are not used as much as on gear drive tractors and often go thousands of hours with out needing to be repaired even on hilly ground. The life span is often two or more times the life of on gear drives if they ever need to be replaced but there is a catch!
They still do need lubrication as well as some action of work to keep them free!!!! We often find that with tractors five to ten year old and more that the brakes will stick in partial on position giving you the same conditions that you had with power.

if I visually inspect them, will I see any stuck brakes?

 

[Komrade]

T

Final thought: HST runs best at high RPMs. So don't be afraid to throttle up the engine close to the rated PTO RPM. On my tractor, that's something like 2200 or thereabouts. I don't always put it full up to 2200 if I'm just tooling around, but any time I'm actually working, it's running at 2200.

Thanks. L3430 (rear) PTO RPMs are 2440. I will try operating it that high (or close) when going up the hill and letting the pedal go as I seem to lose power. Do I need to set them this high when operating the backhoe?

 

[Komrade]

Have you found the page in your Operator's Manual that specs max speed in each of three HST gear ranges?

Fwd:
L 0 to 3.6MPH
M 0 to 7MPH
H 0 to 15.5MPH
Reverse
L 0 to 3.2
M 0 to 6.3
H 0 to 14.0