HST v Hydraulic Shuttle Transmission

[TripleR]

I only have a small CUT, a JD 3520 Power reverser, not a farm tractor. But I am a great fan of the shuttle. You choose a gear combination at leisure then put the reverser in forward or reverse. The hydraulic clutch is pretty fast and I don't think it will let your tractor move down a slope. You can use the reverser at any speed but be prepared for quite a jolt if you are speeding ! You cannot change gears without clutching either with your foot or by putting the reverser in neutral. I have never tried anything easier or more efficient for FEL work : your right hand controls the FEL and a flip of your left hand sends you forward or backwards.

We have HST, Hydraulic Shuttle Shift as well as they old non synchro "crash box" transmissions. While I really like the Hydraulic Shuttle Shift on our M8540, the HST on our L5030 is easier to use doing loader work as well as close in maneuvering.

I grew up farming with geared units then synchro geared then synchro shuttle before going with an HST and like kOua am a true believer, but whatever floats your boat is the best for you.

 

[Kevinc2004]

I grew up operating the geared tractors on the Dairy Farm. But since getting my HST BX1860 I am beginning to realize how much better a Hst would have been for the farm. I will not go back to a geared unit again!

 

[soulasphil]

HST transmissions are wasteful and I'm not sure they have much of a future at a time when oil becomes increasingly scarce and expensive. I notice that no HST is offered on the new JD 5 series tractors. They all have various forms of sophisticated Syncro Reverser, Powr Reverser Plus, Power Quad plus, Auto Quad plus using electric or hydraulic devices to handle gear transmissions. This is what Deere has to say about them : "The Powr Reverser transmission provides 16 forward and 16 reverse speeds with 2 lever shifting. Powr Reverser is perfect for smooth, easy direction changes like for front loader operation." Feels good to learn I'm not the only one of that opinion !
Your friend from France

 

[KabotaTim]

I bought a Kubota L3710 GST w/FEL about 10 years ago that I had for 5 years. I put about 200 hours of use on it and it had a Glide Shift Transmission (GST, aka hydraulically operated transmission w/shuttle shift). I really loved that tractor and transmission setup. Used it for a lot of hard loader work, tree removal and log handling, brush hogging, back blading, and snow removal.

In March of this year I bought a L3700SU HST w/FEL. I've got about 12 hours on this tractor so far and really love it. Here are my thoughts about the HST vs GST:
1. The HST is probably easier to use, but I still find myself sometimes reaching for the shuttle shift to change directions :laughing:. Don't have to worry about manual clutching at all with the HST, so performing delicate or close work requiring small adjustments front or back is much easier and more precise (easy to get close and avoid damage as HST pedal also works like a break to stop your movement).
2. The GST is more efficient (puts more useable HP to work at the wheels and PTO as the HST steals some HP to work the HST pump).
3. I was kind of disappointed when I bought my L3700SU that I could not get a GST tranny, but I must say I am really liking the HST.

Bottom line is either transmission works really good, and I would guess that the larger the tractor, the less the advantages of the HST would be noticeable. The GST is still light years ahead of a regular old gear shift transmission. I don't think you will be sorry at all with a GST, especially in a larger tractor.

 

[dennis52]

Less HP at pto
Higher purchase cost
Higher fuel consumption
More expensive to repair (and I couldn't do it myself)
I did not need it.

Now I am sure, for many buyers the usefulness and convenience of HST outweighs all those considerations.
For me and my slashing (brushogging) work on steep slopes, it wasn't high on the list.

Diesel is $US 6.60 a gal. here today.

 

[Andrewnewy]

HST transmissions are wasteful and I'm not sure they have much of a future at a time when oil becomes increasingly scarce and expensive. I notice that no HST is offered on the new JD 5 series tractors. They all have various forms of sophisticated Syncro Reverser, Powr Reverser Plus, Power Quad plus, Auto Quad plus using electric or hydraulic devices to handle gear transmissions. This is what Deere has to say about them : "The Powr Reverser transmission provides 16 forward and 16 reverse speeds with 2 lever shifting. Powr Reverser is perfect for smooth, easy direction changes like for front loader operation." Feels good to learn I'm not the only one of that opinion !
Your friend from France

Interesting comment, however the real back story to this, is JD were trying to get the new ZF transmission to put into the 5 series, however, Deutz put there foot down (as a major owner of ZF) and so the only tractors in this 100hp range you will see with a true TTV transmission will be SAME-Deutz. The HST transmission we see in the smaller tractors Sub 100hp are similar but a very different kettle of fish, Essentially they are the same concept, but to achieve there flexibility rely 100% on hydraulic power to transfer engine HP to the wheels. (PTO HP doesn't change from an HST to a Gear tractor)
Because of these in-efficences in HST trannys anything sub 100hp, I would go Gear tractor all the way, anything over 100hp, TTV is the only way to fly.
in Particular the Deutz TTV's are designed to apply 100% mechanical power to the wheels in key working ranges. This is the only TTV transmission on the market which can do this. They hold the patent on this design and until someone comes up with something better we won't see this change.

This is why JD are having to pull out there old transmission, they don't have access to anything else.

Another big thing I need to point out, you will notice Deutz are now this year offering TTV transmission completely across the range(some yet to be released) from 100hp to 230hp, this comprises 7 models, this is to completely move away from gear transmissions eventually, and guess what, the market has responded, they can't build them fast enough! particularly in the 100hp market, the new Agrofarm 420ttv is selling out faster than they can produce them!

 

[Andrewnewy]

Less HP at pto
Higher purchase cost
Higher fuel consumption
More expensive to repair (and I couldn't do it myself)
I did not need it.

Now I am sure, for many buyers the usefulness and convenience of HST outweighs all those considerations.
For me and my slashing (brushogging) work on steep slopes, it wasn't high on the list.

Diesel is $US 6.60 a gal. here today.

PTO hp on an HST and Gear will be the same, Same gear setup, however, the HST will take a little bit of power away to drive the Hyd Pump, but won't be much / noticeable.
Higher purchase cost Yes, your currently paying for all the R&D, where as gear is old school, nothing new, all these transmission have been around a long time, even all the power shifters, shuttle shift, hydraulic shift, all old technology, just with new paint on the outside.
Higher Fuel Consumption, yes and No, fuel consumption would be the same on both version if both engines were running at the same speed, However HST typically will always run at a higher RPM, But realistically HST & Gear tractor both running the PTO at 540rpm will use the same amount of diesel
Repair Coststhis could be debatable, I think this will depend on your mechanic & dealer, Really HST is reasonably straight forward, and to some extent there are less pieces than a gear tractor. At the moment parts will cost more. But the whole point of HST is to make a transmission idiot proof, the biggest killer of Gear tractors is Operators riding the clutch, Crashing gears or just selecting the wrong gear and overloading. HST solves all these problems, making it so that you should have the typical problems you have with gear tractors. However if both case's, if you look after it and drive it properly, they will both last many thousand hours with out problem

Fuel costs are going up no question about that!, and in big diesels we are seeing major advancements to reduce fuel consumption, Deutz Latest round of Agrotrons are now dropping back to 4 cyl, but still producing the same power as there predecessor 6 cyl! This is where technology will go. It might be quiet a while before we see this kind of advancement in the sub 100hp units. This will mainly be dictated by price but at the end of the day the CUT market is looking for the best deal.

 

[dennis52]

PTO hp on an HST and Gear will be the same, Same gear setup, however, the HST will take a little bit of power away to drive the Hyd Pump, but won't be much / noticeable.
Higher purchase cost Yes, your currently paying for all the R&D, where as gear is old school, nothing new, all these transmission have been around a long time, even all the power shifters, shuttle shift, hydraulic shift, all old technology, just with new paint on the outside.
Higher Fuel Consumption, yes and No, fuel consumption would be the same on both version if both engines were running at the same speed, However HST typically will always run at a higher RPM, But realistically HST & Gear tractor both running the PTO at 540rpm will use the same amount of diesel
Repair Coststhis could be debatable, I think this will depend on your mechanic & dealer, Really HST is reasonably straight forward, and to some extent there are less pieces than a gear tractor. At the moment parts will cost more. But the whole point of HST is to make a transmission idiot proof, the biggest killer of Gear tractors is Operators riding the clutch, Crashing gears or just selecting the wrong gear and overloading. HST solves all these problems, making it so that you should have the typical problems you have with gear tractors. However if both case's, if you look after it and drive it properly, they will both last many thousand hours with out problem

Fuel costs are going up no question about that!, and in big diesels we are seeing major advancements to reduce fuel consumption, Deutz Latest round of Agrotrons are now dropping back to 4 cyl, but still producing the same power as there predecessor 6 cyl! This is where technology will go. It might be quiet a while before we see this kind of advancement in the sub 100hp units. This will mainly be dictated by price but at the end of the day the CUT market is looking for the best deal.

The spec sheets I have seen on tractor models with a choice of gear or HST (same engine HP) seem to rate HST with lower pto HP

 

[JOHNTHOMAS]

The spec sheets I have seen on tractor models with a choice of gear or HST (same engine HP) seem to rate HST with lower pto HP

How much lower? 1 or 2 HP? 10 or 20 HP?

 

[Andrewnewy]

How much lower? 1 or 2 HP? 10 or 20 HP?

Yes generally only 1 Hp if that, at the end of the day there will be some hp loss to drive the extra Hydraulic pump driving the HST, but in the whole scheme of things 1hp doesn't make any difference!
You would see the same drop in Hp if you have a cab on your tractor with air con.