HST vs. Shuttle shift

[Tx Jim]

ovrszd
IMHO type of trans or type of trans control(shifter) has nothing to do with different ""types of shuttle shifts"". Would you give your theory of how type of trans or how trans is controlled changes type of shuttle shift?
Thank you,Jim

 

[ptsg]

Isn't that just nitpicking at this point?

Different types of shuttle transmission are built differently. It's not just the control of it that changes.

 

[ovrszd]

ovrszd
IMHO type of trans or type of trans control(shifter) has nothing to do with different ""types of shuttle shifts"". Would you give your theory of how type of trans or how trans is controlled changes type of shuttle shift?
Thank you,Jim

Oh my Jim.... Okay, I'll use your 7040 since you are familiar with it. For those that might not know, Jim has a Hydraulic Shuttle lever. A Transmission shifter lever giving him either 4 or 6 gears, they are synchronized. And last a Range lever giving him "high" or "Low". So he either has an 8 speed or a 12 speed. If he has his transmission in 3rd gear and range lever in low, he's in 3rd gear. If he wants to be in 6th gear he leaves his transmission shifter in 3rd and changes his range lever to high. This requires a complete stop. Can't change the range on the move. He's a couple steps better than the most mechanical type of shuttle shift. He's light years worse than the best shuttle shift.

An example of the better/best type of shuttle shift would be the JD road grader that I run. I described it earlier. Here's a condensed version. It's a hydraulic shuttle 8 speed. All power shift on the 8 speeds, no clutch, no stop. Can be running down the road at 28 mph in Forward 8th, toggle the shifter to Reverse and the grader will downshift until it stops forward movement, shift itself to Reverse and start moving in 4th, then upshift thru the gears until it's in Reverse 8th, again going 28 mph. No clutch, no braking, full throttle.

So Jim, would you say these two example of shuttle shift are the same type?

 

[ovrszd]

Isn't that just nitpicking at this point?

Different types of shuttle transmission are built differently. It's not just the control of it that changes.

Absolutely nitpicking. Jim has done this with me on different subjects before. Very predictable.

 

[Tx Jim]

Isn't that just nitpicking at this point?

Different types of shuttle transmission are built differently. It's not just the control of it that changes.

I never stated or implied control of shuttle shift wasn't involved in type of shuttle in fact IIRC I stated it was involved. You can call me nitpicking I call it clarification.

 

[k0ua]

And there are several types of Hydrostatic transmissions. The basics are just a variable displacement piston pump with a swash plate who's output fluid drives a fixed displacement hydraulic motor that drives an old non synchronized 2 or 3 speed gear transmission (the so called range shifter). BUT there are variations on that theme like the Kubota Hydrostat + which has a two speed motor so it "doubles" the ranges, and also electronic controls to control throttle and swash plate angle. Also some of the swash plates are directly controlled by the operators foot, and some are hydraulically controlled and some are electrically/hydraulically controlled. Cruise controls can be mechanical, or electric/magnetic or maybe by electronic means.

But I really don't want to get into this discussion.

 

[ovrszd]

And there are several types of Hydrostatic transmissions. The basics are just a variable displacement piston pump with a swash plate who's output fluid drives a fixed displacement hydraulic motor that drives an old non synchronized 2 or 3 speed gear transmission (the so called range shifter). BUT there are variations on that theme like the Kubota Hydrostat + which has a two speed motor so it "doubles" the ranges, and also electronic controls to control throttle and swash plate angle. Also some of the swash plates are directly controlled by the operators foot, and some are hydraulically controlled and some are electrically/hydraulically controlled. Cruise controls can be mechanical, or electric/magnetic or maybe by electronic means.

But I really don't want to get into this discussion.

Excellent explanation James!!! You've thrown yourself under the bus!!!

 

[k0ua]

Oh, and to the Original Poster, aren't you really really glad you asked about the difference between shuttle and hydrostatic transmissions?

You never knew it was all this complicated and would bring so many people out of the woodwork did you?

 

[Tx Jim]

ovrszd
After being employed at a JD dealership for 21 yrs with 13 of those yrs serving as dealer service manager I'm probably as much or more knowledgeable about a JD Powershift trans as you. But in my opinion Powershift trans is just that a semi automatic trans not a TRUE shuttle shift which this thread was originated about but if you want to call it a shuttle shift is fine with me.

 

[ovrszd]

ovrszd
After being employed at a JD dealership for 21 yrs with 13 of those yrs serving as dealer service manager I'm probably as much or more knowledgeable about a JD Powershift trans as you. But in my opinion Powershift trans is just that a semi automatic trans not a TRUE shuttle shift which this thread was originated about but if you want to call it a shuttle shift is fine with me.

With that criteria, all of James' examples are just one type of HST.