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

[KennyV]

I disconnected the linkage on the dry clutch over 10 years go... this allowed me to hook the clutch peddle down and out of the way... Have not used it for some time before I disconnected the linkage so I know the hydro shuttle and wet clutch packs are working just great, I have never had any problem inching forward or backwards for 3pt hookup. KennyV

 

[ovrszd]

So you can select a gear, engage the GST to move forward, then hold the movement by braking like an AT trans in your truck? Similar to a shuttle system in a construction backhoe for example?

I gotta find one of those that I can drive for a few minutes!!!

 

[Fallon]

Glide Shift is not constant mesh like PowerShift is and has only fork shifted synchronized gear sets with ECU modulated hydraulic multi disk clutches.

David

I assume so, but from an operators point of view they function the same. PowerShift will shift pretty much instantly, GST has a 1-2 second pause in power while the clutch is out, it shifts, then it let's the clutch back in.

Driving some 7 & 8 thousand series JD machines a decade or 2 ago in college it was impressive. While plowing tapping the clutch would stall the machine, but you could often up shift & keep on going. Truly impressive transmissions.

 

[Fallon]

So you can select a gear, engage the GST to move forward, then hold the movement by braking like an AT trans in your truck? Similar to a shuttle system in a construction backhoe for example?

I gotta find one of those that I can drive for a few minutes!!!

Not quite. It has a clutch not a torque converter. Applying brakes while in gear would lug or stall the engine. You can use the F/N/R lever to ride the clutch & inch forward or backwards.

 

[David_Kb7uns]

Most PowerShift diagrams I have seen have 2 clutches and 2 gear trains andthe clutches flip back and forth with the gears being preselected. GST is just an automated Fully Synchronized Transmission.

On inching with a GST I will either put foot lightly on brake or engage 1st click of parking brake and use throotle a little above idle while moving shuttle lever in desired direction and releasing. The brake keeps tractor in place or from rolling as there is no connection of wheels to drivetrain while in neutral.

David

 

[ovrszd]

Not quite. It has a clutch not a torque converter. Applying brakes while in gear would lug or stall the engine. You can use the F/N/R lever to ride the clutch & inch forward or backwards.

Oh, so with the GST by "riding" the lever you are slipping the hydraulic clutch to allow inching. Same thing I do with my clutch pedal on the Kubota. No big mystery there. Thought the way KennyV stated it he wasn't using a "clutch" at all. Maybe he just doesn't realize he's using a hydraulic clutch?? So what's the purpose of the clutch pedal??

 

[KennyV]

So you can select a gear, engage the GST to move forward, then hold the movement by braking like an AT trans in your truck? Similar to a shuttle system in a construction backhoe for example?

I gotta find one of those that I can drive for a few minutes!!!

NO you can not... The shuttle will accomplish disengaging the wet clutch pack and selecting F/R and then re-engaging that clutch pack... will Not allow stop while clutch pack is engaged... But the hydraulic pressure that is used to activate the clutch pack is moderated to feather the engagement ... KennyV

 

[ovrszd]

NO you can not... The shuttle will accomplish disengaging the wet clutch pack and selecting F/R and then re-engaging that clutch pack... will Not allow stop while clutch pack is engaged... But the hydraulic pressure that is used to activate the clutch pack is moderated to feather the engagement ... KennyV

So to inch forward/backward you cause the shuttle to slip under reduced pressure?

 

[KennyV]

Maybe he just doesn't realize he's using a hydraulic clutch?? ...
... So what's the purpose of the clutch pedal??

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

 

[MHarryE]

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.