GST Transmission tips or tricks?

[npaden]

Okay, I'm stuck in the office and haven't been able to use my new to me L4200 GST more than an hour tops since I got it last Friday.

I test drove a L5030 GST as well, and ran my L4200 for about an hour smoothing my driveway and had a few questions about how those of you with the GST transmission are using them.

What I found myself doing is for the most part picking the gear I wanted to start in and clutching it to make it start smoothly. In the lower gears (1 - 4) it seems to go pretty smoothly but shifting from 5th it seems to go into the next gear pretty hard and even on the brand new L5030 that I test drove it actually spun out when I went from 10th to 12th gear even when I let off the foot throttle between the shift. Do you try to clutch it a little bit to make the higher shifts smoother or do you just let it shift hard and go on with life?

When I messed around with the loader for about 15 minutes I had it in 3rd and that was relatively smooth to go back and forth between forward and reverse but I think it will take a little getting used to operating the loader joystick with my right hand and and moving the shifter back and forth from forward to reverse with my left hand.

I'm just looking for any tips or tricks from people that have been using the GST transmission longer than the 1 whopping hour that I have on the clock.

Any input would be appreciated.

Thanks, Nathan

 

[KennyV]

Nathan:
You will quickly get familiar with the shifting of the transmission. Your foot clutch is a standard, single disk, DRY type… The GST has another clutch in it, a multi disk WET clutch. It will take a lot of abuse and never give you problems. The dry clutch will not take anywhere near as many cycles. You will get familiar with the feel of the shifter and shuttle lever as you feather in the hydraulic clutch. I have not used my foot clutch in years and I have well over 900 hours on my L4200GSTC. KennyV.

 

[npaden]

Thanks for the input!

I know you have the same machine but didn't want to pester you via PM on something that later people might search and get the answer on the main board.

You say that I will get used to the feel of the shifter as I feather in the hydraulic clutch. What exactly do you mean feather in the hydraulic clutch? Do you mean letting off the foot throttle then switching gears and then as it comes back into gear stepping down on the foot throttle?

I think I had the lever throttle up a little past idle so that's part of why it was jumping a bit more than I expected when shifting between gears.

If you don't mind another question specific to the L4200, do you have to push down on the forward and reverse lever when it is in neutral to start it? On mine even if everything is in neutral I need to push the forward and reverse handle down to turn the starter over. Not sure if that is standard or if the shifter switch is just worn on mine.

Thanks again for the input!

Nathan

 

[_RaT_]

<font color="blue"> The GST has another clutch in it, a multi disk WET clutch. It will take a lot of abuse and never give you problems. </font>

Interesting, the wet "Ever Clutch" in our Kubota L4850 feels like it is in need of replacing.

 

[KennyV]

Nathan
When you select a gear, several things happen… The clutch pack will disengage, Then the gear you have selected will engage and Then the clutch will reengage.
The forward, reverse shuttle will do the same thing. It disengages the clutch pack and selects either forward or reverse… If you move either lever slowly you can control how rapidly the clutch pack will reengage. That will allow you to feather the clutch in… same with the PTO engagement lever, you can slowly move it toward on and it will slowly close the PTO clutch pack.

You might check your shuttle lever spring. I have replaced mine. The spring actually moves the lever to engage the neutral safety switch. The spring has two legs on it and I had one break off and had the same trouble you have. Very easy to replace and if you remove the cover at the lever you will see the spring. It’s only a couple dollars, and easier to replace than it is to describe…

RaT… I think that is the same clutch pack… Runs in oil, very hard to burn or overheat… dose it feel like it is slipping under load or chattering as it engages? How many hours on that tractor? KennyV.

 

[KennyV]

Nathan… I almost forgot… PM anytime that’s no problem /forums/images/graemlins/smile.gif, I’m just glad to see someone else here with a L4200. There are a few of us around. For a relatively small tractor it will surprise you how much work it will do /forums/images/graemlins/cool.gif. KennyV.

 

[_RaT_]

Slipping, no chatter

 

[KennyV]

Can you be sure it is not the dry clutch? /forums/images/graemlins/confused.gif KennyV.

 

[JimMorrissey]

Kenny....You have not used the stardard foot clutch in years????? What about loader work and tight situations. Can you give us some more details on how you do this. I'd like to not use my clutch as much as I do, but I just can't make my foot to avoid it....Apparently I have more to learn on the GST tranny.

 

[KennyV]

Hello Jim:
Spring has tried to make it a few times already; I think it’s just around the corner now… my allergies are thinking so /forums/images/graemlins/crazy.gif…
Using my loader even with forks has been no problem, I use the shuttle and with tilt wheel you can give what little input on steering that you need with your knee. Left hand on wheel/shuttle. Right hand on joystick and right foot on accelerator pedal. There have been times it seemed kind of busy but not enough to be any trouble. Using the loader with a tree shovel attachment was probably the most problem until I discovered how handy the Creep speed was for really tight spots. I do have large turf tires on and they may give me just enough slippage while digging to give that moment of time to reverse or neutral, but no problems even loading into the side of my dump truck. I am never running against a clock, so not really trying for maximum production. I guess having OLD tired knees is the main thing that keeps me from using foot clutch but so far I like it. I do every now and then push the clutch so as to keep it usable, but for a practical use the pedal could be removed… I’d not notice it gone. KennyV.

 

[npaden]

Okay, now I found out I have tilt steering too! The lever is broken off though. Looks like I've got some tinkering to do!

 

[SkyPup]

Taken from “New Features of the Kubota Grand L30 Series Compact Tractors”

The Glide Shift Transmission (GST) is original Kubota technology which provides 12 forward and 8 reverse shift-on-the-go gears without the need for clutch operation. The GST has a hydraulic clutch and transmission gears that are changed by the action of an actuator located in the transmission. When the operator initiates a gear change, the GST automatically performs a series of operations that includes disengaging the hydraulic clutch prior to the gear change, changing the gears and then engaging the hydraulic clutch after the change.

The ECU allows for a single shifting lever that actuates a potentiometer signifying the specific gear selection. In the Grand L30 series tractors, the ECU controls a proportional pressure reducing valve, solenoid valves, and performs a gear change by operating a hydraulic clutch.

With this GST system the pressurization of the hydraulic clutch can be set by a proportional pressure reducing valve for limitless stages, all of which is controlled by the ECU. The tractor is equipped with an engine tachometer sensor and a travel speed sensor, as well as a potentiometer that distinguishes the position of the gear selection lever. Based on digital signals from the engine tachometer sensor and the potentiometer, travel speed after the completion of a gear change is calculated, while the travel speed sensor calculates the actual travel speed. Based on the difference between the two speeds, the pressurization characteristics of the hydraulic fluid supplied to the clutch is set. Thus the Kubota GST brings about a smooth gear change by changing the pressurization characteristic in response to the various patterns of gear operation.

Acceleration of the tractor is calculated based on digital signals from the travel speed sensor. Under conditions when the tractor accelerates rapidly, the pressurization is changed to become slower during the pressurization process. When the tractor accelerates slowly, the pressurization is changed to be more prompt.

After the hydraulic clutch begins engaging and the acceleration of the tractor starts, the acceleration is calculated and the pressurization characteristic is compensated. Tractors may be equipped with a variety of different implements according the context of work users wish to perform. In particular, when an extremely heavy implement is attached to the tractor, acceleration does not occur until the compensation begins, which makes gear change time much longer. Therefore the compensation of the pressurization characteristic based on the total tractor weight is realized. The offset can be input using the “Adjustment Mode” of the IntelliPanel, with the correct offset stored in ROM. The ECU of the GST takes in the correction value by communicating with the ECU of the IntelliPanel and compensates the pressurization characteristic. The offset is just a derivative of the diameter of the tractors tire diameter.

 

[npaden]

After operating my tractor for about 10 hours over the weekend one thing that I notice on my tractor was that the shifting from forward to reverse actually seems to be a little easier when the tractor is still moving slightly. When I say slightly I mean very slightly, wheels are barely moving.

If I came to a 100% complete stop sometimes it didn't want to shift into reverse so I had to move it forward a tiny bit to get it to go into reverse.

Not sure if that is specific to my tractor or if they are all like that.

FWIW, Nathan

 

[Muleskinner]

I'm starting to have a possible problem with my GST on my L39. Some times if I shift from forward to reverse or from reverse to forward before the engine completly idles down the trans will grind slightly like a bad syncro. Also some times if I shift from forward to reverse there is a short delay before the trans will engage. (Five seconds) Once or twice I have even had to shift the shuttle back to forward and then back to reverse to get the trans to engage. Any ideas? /forums/images/graemlins/confused.gif

 

[SkyPup]

Be sure to let it hang in neutral for about a second before going into F or R, do not simply go from F->R or R->F.

 

[skyhook]

Okay, now I found out I have tilt steering too! The lever is broken off though. Looks like I've got some tinkering to do!

Just reviving an old thread,
npaden, I have the exact same tractor 1996.
You probably don't have it any longer.

SkyPup, I don't think my 1996 L4200gst has this ECU yo speak of.

 

[johnk]

I have a 3130 GST 2008 over 500 hours and no problems.........