Can the lag time between shifts on a L3710 GST be adjusted?

[unioncreek]

Just picked up a L3710 GST, haven't been around a tractor with a GST before. To me the pause between shifts after moving the gear shift seems to be too long to me. Is there some way to adjust the transmission to shorten the time between shifts? If I throttle back as I shift there is no pause.

Any help would be appreciated.

Bob

 

[PoTreeBoy]

Just picked up a L3710 GST, haven't been around a tractor with a GST before. To me the pause between shifts after moving the gear shift seems to be too long to me. Is there some way to adjust the transmission to shorten the time between shifts? If I throttle back as I shift there is no pause.

Any help would be appreciated.

Bob

Do you have the manuals? They may be available at KubotaBooks, I'm not sure if they cover the GST model.

There are some adjustments, but before you get into that I'd change the fluid and filter, making sure to use only Kubota SUDT2 fluid.

Does it by chance chirp when you first shift it after initial startup? That's à sign of air in the lines from a suction line leak. It's pretty common and needs to be corrected.

This transmission is all hydraulically controlled and is pretty complex, there is even some circuitry that deliberately slows the shifts in the 4-8 gear range.

 

[unioncreek]

I did download the manual from Kubota Books, my laptop hasn’t been working so I’ve been looking at it on my phone.

No chirping. The previous owner wrote the date of filter changes and has about 40 hours on it. The transmission oil is clear, but I’ll change it so I know it’s new.

Is Kubota the only place to get oil.

Bob

 

[PoTreeBoy]

Is Kubota the only place to get oil.

Bob

No, you can read plenty about it on this site.

But there have been reports of GST shifting issues when universal type fluids were used. SUDT2 isn't cheap, but it isn't out of line with other synthetic fluids.

 

[North Idaho Wolfman]

On a GST I only use 2 fluids.
Kubota SUDT2
Mystik JT 5

 

[N3BP]

The GST transmissions do have an undesirable lag between shifts. It's annoying but nature of the beast. About the only time you can get one to shift quick is if your up-shifting going down a hill. I don't believe there is anything you can do to speed up the shifts as it needs to synchronize naturally. Sometimes it's best to pre-select a gear.

 

[unioncreek]

On a GST I only use 2 fluids.
Kubota SUDT2
Mystik JT 5

Have you had any trouble running Mystik JT 5?

 

[North Idaho Wolfman]

Have you had any trouble running Mystik JT 5?

Zero issues with it, and I've been running it for 10 years in my GST and several others.

 

[PoTreeBoy]

The GST transmissions do have an undesirable lag between shifts. It's annoying but nature of the beast. About the only time you can get one to shift quick is if your up-shifting going down a hill. I don't believe there is anything you can do to speed up the shifts as it needs to synchronize naturally. Sometimes it's best to pre-select a gear.

You definitely don't want to downshift going up a steep hill, unless you use the foot clutch and brakes to prevent it from rolling back and popping the clutch.

 

[lugbolt]

gst's are really sensitive to the fluid....

 

[unioncreek]

I’m going to be changing the oil, hopefully next week.
Bob

 

[pigdoc]

Automatic transmissions in cars are valved or adjusted so that there is overlap between the gears to minimize the lag or abrupt change in torque when you shift. The two adjacent sets of clutches are actually both partially engaged at the same time, momentarily. This is to satisfy the needs of the 'typical' driver, in the quest for 'drivability'.

So-called "shift kits" for these transmissions come in a wide range of aggressiveness to more-or-less eliminate that overlap or lag. Gives nice CRISP shifts! If I get on my 6000-pound Cummins truck (with a moderately aggressive shift kit in it) it will chirp the tires when it shifts from 1st to 2nd, because there is much less overlap between the shifts than 'stock'.

I doubt anyone is marketing shift kits for the GST, just sharing a concept...

I don't know anything about GSTs, but for automotive ATs, it is also possible to adjust line pressures and band tightness to change drivability as well. That's not something for the amateur to play with. You can toast an AT very quickly if you over-tighten the bands! [Been there, done that.]

-Paul

 

[unioncreek]

The tractor sat for about a year it was part of an estate, they had changed all fluids and filters just prior to it sitting. I’m going to change the transmission fluid within the next couple of weeks. The lag time has shortened the more I use it. And as I become more familiar with using the tractor I understand better what it’s doing.
Bob