What is correct way to drive an M7040 with hydraulic shuttle shift?

[ovrszd]

I'm Very aware of the wet clutch pack.... and how it works. (and NO you can Not 'ride' the shuttle lever to slip the clutch pack). Clutch pack is fethered using the GST hydraulic pressure regulation.On a GST tractor the clutch pedal has no real purpose, so it can be disconnected, as I have done... Or just not used as many do... Or use it if you like.
I could see no reason to ware the dry clutch, pressure plate, through out bearing and pilot bearing so I have never used it... and because I never use it I just locked the pedal down to get it out of the way in my cabbed tractor. KennyV

So what controls the GST hydraulic pressure regulation to allow the tractor to "inch"??

 

[ovrszd]

Although it is easier on the transmission components to stop when shifting the shuttle, my book says to slow the engine and don't shift from forward to reverse or vice versa at speeds greater than 6.8 mph or it will cause a fault. I gather a lot of large bales and usually shift while still moving - Stan a bale with the rear spear, while still moving but at lower engine speed shi t the shuttle forward, spear a bale with the front on the go and head for the bale wagon. My operators manual describes pretty well the dos and donts of shuttle shifting.

Very good description of what I see here by my neighbor cattle ranchers on tractors of all colors with hydraulic shuttle or Power Reverser.

 

[Fallon]

So what controls the GST hydraulic pressure regulation to allow the tractor to "inch"??

Bump the shuttle lever or ride the dry clutch Iike you would with a normal gear transmission.

I helped my brothers father-in-law with some brush & tree cleanup running his L4?30 GST. I never did get the timing on the shuttle down in the hour or 2 I ran the machine. I kept reverting to the dry clutch & brakes to stop where needed. A few more hours i expect and I'd have adjusted to using the shuttle lever only & not messing with the dry clutch.

 

[Baby Grand]

When moving & shifting our GL3240GST I treat it like an Eaton 2 speed rear end on a medium duty truck - I back off the fuel enough to take the torque load out of the drive train and shift, then once it's engaged I'm back on the fuel. There's a 1 or 2 Mississippi lag before it reengages, so I limit my shifts to when I 'm not climbing or going down any steep grades. For starts from a dead stop, I use the dry clutch, and for fine maneuvering - say hitching 3pt implements or trying to pick a load out of a truck with a chain on an FEL hook without hitting the truck or swinging the load, I also use the dry clutch, but those are the only times. Very, very happy with the GSTs ability to transfer power efficiently on my lower power/weight tractor, while still freeing my left foot from constant double clutch duty when running the FEL.
-Jim

 

[sixdogs]

Is the GST still offered on new Kubotas?

 

[ovrszd]

When moving & shifting our GL3240GST I treat it like an Eaton 2 speed rear end on a medium duty truck - I back off the fuel enough to take the torque load out of the drive train and shift, then once it's engaged I'm back on the fuel. There's a 1 or 2 Mississippi lag before it reengages, so I limit my shifts to when I 'm not climbing or going down any steep grades. For starts from a dead stop, I use the dry clutch, and for fine maneuvering - say hitching 3pt implements or trying to pick a load out of a truck with a chain on an FEL hook without hitting the truck or swinging the load, I also use the dry clutch, but those are the only times. Very, very happy with the GSTs ability to transfer power efficiently on my lower power/weight tractor, while still freeing my left foot from constant double clutch duty when running the FEL.
-Jim

Very good explanation!!!! That's what I was looking for. I got it now. Thanks Jim!!!!!

 

[Fallon]

Is the GST still offered on new Kubotas?

Yup. They stop offering HST or HST+ on bigger machines. Usually after 60hp or so. I love HST & HST+ for my CUTs, but the use case for bigger machines is efficiency & max power transmission for field work, not flexibility & ease of use. The 15% HST HP tax just isn't worth it on the big boys.

 

[Fallon]

Yup. They stop offering HST or HST+ on bigger machines. Usually after 60hp or so. I love HST & HST+ for my CUTs, but the use case for bigger machines is efficiency & max power transmission for field work, not flexibility & ease of use. The 15% HST HP tax just isn't worth it on the big boys.

And that goes for all manufacturers, not just Kubota. Pretty sure all the Grand Ls offer HST+ or GST. I think the Ms have GST or some other shuttle options.

 

[ovrszd]

And that goes for all manufacturers, not just Kubota. Pretty sure all the Grand Ls offer HST+ or GST. I think the Ms have GST or some other shuttle options.

Not sure I even had an option on my M when purchased in 2012. Hydraulic Shuttle. Only choice was 8spd or 12spd or 24spd (with creep).

 

[JWR]

I'm surprised how this thread has gone on to 40 posts. And had me puzzled more than once about which transmission was under discussion. I found a site at What is this Shift? Understanding Kubota Transmissions — Humphreys' Outdoor Power which describes in very good detail the plain gear drive, HSD, GST and HST types of Kubota transmissions. The GST (being a stick shift with no requirement to use the clutch) seems to be unique to Kubota. Interesting.