Kubota L39 GST shift speed

[caballero59]

My L39 has a significant pause between shifts. I really don't like this. All the Deeres I've operated with power shift (7210, 6415, 8100, 8210) are positive and immediate while still being smooth. When I shift, I always let up on the throttle a bit to ease the shift anyway. There is absolutely no reason to have such a delayed shift that the tractor stops and rolls backward, losing all forward momentum. I've heard the computer can be adjusted for faster shifts. Does anyone know anything about doing something like this?

Scott

 

[caballero59]

Thoughts?

 

[KennyV]

The WSM has detailed information on setting up the hydraulic pressures in the transmission, that is where you need to set the GST shift speeds.
When properly set the GST is a great system. KennyV

 

[caballero59]

Can a swift positive shift be achieved with this tranny?

 

[Fallon]

The only other GST I've driven (L4?30) had noticable shift pauses as well. The 7000 & 8000 series JDs I drove years ago were instant & impressive. But I think they were dual clutch type trannies.

 

[ProjectKing]

Can a swift positive shift be achieved with this tranny?

What does swift mean? 0.5 second? 1 second?

I have operated a L39 and it shifted fine. You maybe confusing the transmission by letting up on throttle. When are you doing this?

 

[caballero59]

So what I've gathered from the responses is that the shift cannot be as positive as the Deere because of the Deere's dual clutch system but perhaps can be sped up a bit by adjusting transmission pressures. What a great tractor if it shifted like a Deere!

 

[dfkrug]

All the Kubota GSTs I have operated (4 or 5) shifted quickly and positively. I always
let up a bit on the engine speed controller pedal as I shifted. I don't recall what the
operator's manual said about that, but the internal wet clutches are servo-controlled
from what I have read, and they should be able to shift under load.

Has anyone here been inside a GST?

 

[David_Kb7uns]

The Kubota GST and Deere Power Shift are two different things. Power Shift is constant mesh gears and the clutches are alternated. The GST must clutch servo shift the gear forks and modulate the feathering of the clutch.

The Grand L3130 that I have with GST has engine speed, wheel speed, transmission temp sensors that go into the ECU for shifting. So the closer the speeds are when shifting the quicker the lockup time is.

Have found that Super UDT gives better shifting performance. For fastest shifting use the foot throttle and run the throttle like you are driving a truck and going through the gears, it makes shifting the quickest, if under light load will skip 1 or 2 speeds when shifting but above 8 or 9 will hit everyone as they get wider on spacing there.

If the ECU fails there are usually 2 connectors that you connect together after unhooking the ECU to force the 1st gear to be selected in order to move tractor for service.

Never been inside a GST but it looks like it has a valve body with servos for the shift forks and solenoids similar to an automatic transmission.

Would not play with pressures much it is computer controlled standard shift gear transmission that shifts very fast compared to other operators.

David

 

[caballero59]

Thanks for this info David.