# Newbie transmission question



## clattin (Dec 8, 2004)

Being new to tractors, I think I understand the concept of a hydrostatic transmission; but what is a shuttle shift? Is it just a fancy way of saying a geared transmission? I keep seeing "synchronized shuttle shift" and I simply don't know what that is.

Thx in advance,
Chris


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## mark777 (Jul 23, 2004)

*Shuttle shift*

Clattin,

The shuttle shift is an internal package of bearings and gears that stop the planetary motion or inertia and allow the operator to shift from gear to gear, or from forward to reverse without the use of the clutch.

I have yet to tare one apart as they are tenacious in their design. In fact John Deere and Yanmar mechanics often refer to them as "Bullet Proof".

They are best utilized with a combination of implements that include loader work. Either I'm lucky or they are that good, as I have yet to have one fale.

Regards, Mark


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## clattin (Dec 8, 2004)

So functionally it's just like a hydrostatic transmission? Is it safe to say that it's more reliable? I've heard that service on a hydrostatic can be very expensive.

Thx again,
Chris


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## mark777 (Jul 23, 2004)

Hmmm...More reliable? I don't know about that as it may start the controversy of Geared vs. Hydro vs. shuttle shift.

Hydrostatic drives have come along way...and I think routine scheduled maintenance issues, when strictly followed make the hydrostatic transmissions very reliable. The ones you hear about in the shop are usually serviced (or overhauled) because of neglect. 

I believe that shuttle shift transmissions divert a little more HP and Hydros sip very little HP required to drive the whole operation (option). These are my opinions from gathered sorted literature and collective feedback on other forums. In other words....I'm no expert. My own personal experiences are from owning geared and shuttleshift Yanmars.

Mark


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## Argee (Sep 17, 2003)

Now I understand shuttle shift a little differently....I understand it to be a directional lever separate from the range gears that allows you to shift from forward to reverse with the use of the clutch and synchro's quickly and stay in the same range. This makes it ideal for loader work. My neighbors Kubota works this way and I believe New Holland is similar...maybe John Deere has taken it to the next level.


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## Michael (Sep 16, 2003)

My thinking the best for loader work is most likely Hydro because you are not fumbling around with one thing to think about and it leaves you more time to control the loader then to think and reach for a gearshift lever. That is my experience with my Kubota L185 manual shift with a loader. I have to plan ever more carefully and have to be on my toes to get it operate smoothly. Most times I can easily do what I want but when I am using the loader with straps and loading something into or out of my truck I have to think carefully and work very slowly.


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## slipshod (Sep 19, 2003)

*shuttle shift*

Let me explain this the best way that I can. Shuttle shift is nothing more then the ability to change the direction of travel without changing gears or using the clutch. The machine in theory will go in the opposite direction at the same speed and power it was traveling if the throttle position is the same.
I own a 4600 John Deere with shutttle shift. The gearing on my machine is as follows; a fully synconized 4 speed , connected to a three range gear box. The four speed can be shifted up or down the range by using the clutch on the fly, from any gear to any gear. To change the gear range you have to stop and use the clutch to change from one range to another, clutch optional if 4 speed is in nuetral. 
The shuttle feature is a lever on the dash that has three positions forward nuetral and reverse. It is a great tool if you use a loader as I do. Mine has preformed flawlessly for over 1000 hours. The forward and reverse peddles on a hydrostatic model do much the same thing as a shuttle shift. 
I for one think the set-up I have is excellent and has handled any thing I have thrown at it.


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## Glenn9643 (Jan 22, 2006)

*Re: shuttle shift*



> _Originally posted by slipshod _
> *Let me explain this the best way that I can. Shuttle shift is nothing more then the ability to change the direction of travel without changing gears or using the clutch. ...
> 
> The shuttle feature is a lever on the dash that has three positions forward nuetral and reverse. It is a great tool if you use a loader as I do. Mine has preformed flawlessly for over 1000 hours. The forward and reverse peddles on a hydrostatic model do much the same thing as a shuttle shift.
> I for one think the set-up I have is excellent and has handled any thing I have thrown at it. *


Shuttle shift is available from various manufacturers in differing configurations. Some shuttles require clutching when changing from forward to reverse. Mine does. With Massey's "Power shuttle" option no clutching is necessary as described above. More convenience generally means more $$$.


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## Live Oak (Dec 22, 2003)

The "sync shuttle" or shuttle which requires clutching to shift is more or less a reverse gear or gear range that the transmission or final drive transmission is shifted into in order to go backwards. 

The "power shuttle" or shuttle which requires NO clutching is not a true gear per say. It is a multi-range hydraulicly actuated clutch pack within the transmission that when selected engages a corresponding gear set. On most tractors the clutch pack has a forward and reverse range or "shuttle. On some older equipment such as the D and older model John Deere 450 dozers and track loaders; this clutch pack was called an "HLR" or high/low reverser. This arrangement offered a high and low range without clutching as well as reverse. This was a real nice feature but it was a royal pain in the ass to repair when the o-rings in the clutch pack failed, which was more than occasional. Some larger model row crop and ag tractors also have this feature which again is real handy when it works but a HUGE expense to repair.


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