Glide Shift(GST) vs Hydrostatic(HST)

[Vincent]

Who has experience operating both GST's and HST's in Grand L series Tractors? I would appreciate your comments regarding the relative merits (as well as drawbacks) of these transmissions for tasks such as loader operation, road maintainence, and cultivation.
At this time I'm biased toward the GST as the gear selection can be used to control ground speed while the throttle maintaines engine RPM and implement hydraulic performance. It seems to me that the HST varies both these parameter at the same time. I have experience with manualy geared equipment and know that is not the way to go for ease of operation or safety but do not have actual experience to properly evaluate the relative performance of these two well enginerred transmissions.
Muhammed has continually improved this site and I have enjoyed reading the fine, often spirted theads on this board for the about past year. While this is my first post I am confident that the collective experience of the users will help me make the right decision when the time comes.

 

[MChalkley]

Vincent, would you do me a favor while I work on a reply to your question? Click on the 'Archive' link at the top left of each page, then go to 'Keyword Search' and search for '+hydrostatic +gear' in the Kubota forum. That should point you to the times we've thouroughly thrashed this one on the old forum, but we might as well do it again on the new one...

 

[MChalkley]

Vincent, I traded a '97 L3600GST for a '99 L4310HST so I could get the hydrostatic trans, so that tells you where I stand, if you haven't already found out from the archives.

There are two areas I can think of in which gear transmissions excel over hydrostatics: when precise ground speed control is critical, and when using the tractor extensively for plowing or pulling other hard-to-pull ground-engaging implements.

It's usually not very practical to control ground speed with gearing alone. Far better to set the engine to produce the power and/or hydraulic flow you need and vary the ground speed with the transmission alone. Diesels work best when set to an appropriate rpm and left there. I burn at least a third less fuel on my more powerful L4310 than I did on the L3600, primarily because I'm not messing with the throttle all the time. Diesel tractors bear no resemblance to gasoline cars when it comes to performance characteristics.

Contrary to what you said, the HST does not vary 'both these parameters at the same time', though I'm not sure which two of the three you mentioned you were referring to. The HST pedal only varies the ground speed of the tractor, by changing the effective 'ratio' of the transmission. It's really controlling the speed of the pump and motor in the transmission, but has the effect of varying the ratio in the process.

Aside from the two exceptions I mentioned earlier, I've found hydrostatics to be infinitely easier to use (pretty important), safer (more important than anything else), and more productive (very important to me). Do you want more details/evidence? I don't want to be too skimpy with the info, but I don't want to repeat myself unnecessarily, either. Like they say: You make the call. /w3tcompact/icons/smile.gif

 

[MChalkley]

I can't believe the "brain trust" is going to leave my post to stand without comment. Surely you guys have something else to add... /w3tcompact/icons/smile.gif

 

[gordon]

For me it's a tough call both have good and bad points. All in all if I were to buy a new tractor it would have the glide shift trans, because of what I use my tractor for. For loader work a hydro would be better. I do believe a hydro is the safer of the two but the hydro pedal and brake can be a real pain for me. I do alot of brake steering while pulling and feel more comfortable with the glide shift---Thats my two cents worth

 

[Anonymous Poster]

Since I decided on an L35 over a L with an aftermarket hoe my choice was made for me (GST) but it would have been a tough choice. I have a BX with a hydro and the L35 with the GST. I'm happiest when I can just get on something and use it. 17 years with a Gear tractor made the L35 a dream, no bending to shift, no clutch to use unless you want. Full power but good speed control as the engine is so torquey it goes up easily at any rpm. The hydro is fun on the BX but I haven't got to the point that I can stop and backup and go forward without jerking myself to pieces, and I'll probably never get used to it since I don't have to worry about how I release the throttle on the L35. The HST models have no where near the hydraulic flow that the L35 has, and an aftermarket backhoe even a frame mount didn't fit my bill so the choice was made for me. Fortunately I'm happy with it. I still don't understand how an HST is safer. Maybe if you're planning on having a heart attack while driving. I still wonder why Kubota does not put the HST in the "industrial use" L35 when it's a kissin' cousin to the L3410. That aspect still sends up a red flag (to me). People that are buying these are using them as a loader and wouldn't buy them if they didn't work.

And the brakes are another item. I use the tractor for moving cars, stumps in tight areas, sometimes if you can't brake turn you can't move the object where you want it. I agree with previous discussions on general turning, even in tight areas, with the HST you can slow it down to .0003 miles per hour and creep around an object (of course isn't that less productive, going SLOWLY (hee hee Mark) when you can pivot at max speed? (great for scaring the family) OK Mark, your turn.

 

[Thomas]

Good Morning Vincent.
When I bought my Kubota I wanted a front end loader which I knew I was going to be useing alot,brush hogging,removing rocks,land scaping,snow removeal etc.. and I choose HST.
I'm very please w/ the HST.
Can you compare GST & HST at your local dealer....in a practice pit ?
Take Care.

 

[PaulB]

I am going to answer this post as I did the one on the L2500 and live vs non-live pto...WHERE IS YOUR DEALERS HEAD, UP HIS BUTTOCKS? How can you walk out of a dealership and not know that HST affects only ground speed, if the dealer is doing his job? This is called education not just making a sale. Of course I think you should get HST, precisely because you wnat to be able to run at full rpm with unlimited control of ground speed, but I am more distressed at the fact that your dealer didn't tell you this. Maybe you have only been window shopping so far, and if so I apologise for being critical, but maybe I am spoiled by having a good dealer who really TAUGHT me what to look for in my tractor. And del, as far as safety I believe the main point is that the time required to simply lift your foot off the HST pedal MUST be less than the time required to push in the clutch and release the throttle and shift into neutral in a panic situation.

 

[art]

Mark, this doen't happen to often but let me take advantage of your opening. If you need to maintain a constant ground speed how do you do it with a gear or gst transmission? The only one you can go over hill or dale at a constant speed with is a hydro.

 

[W5FL]

Did I miss something? /w3tcompact/icons/blush.gif My Kubota is a gear (only way it comes). It goes over hill, dale, hood high grass and the ground speed doesn't vary any at all. The Diesel just takes a little more fuel and keeps a constant ground speed. That is the main disadvantage of the hydro and the advantage of the gst and gear transmissions is that they DO maintain constant (and very predictable) ground speed.

 

[PaulB]

I think what Mark meant was they are excellent at maintaining a given ground speed (better than HST) but the speed is not infinitely variable, as it is with HST. If you have 8 forward gears and ruN at 2600 rpm, you have 8 different ground speeds. My HST has an infinIte number of speeds, but unless I use cruise control I can not PRECISELY maintain a given desired speed. If gear 5 is a little slower than you want, and 6 is a little too fast, what do you do?

 

[W5FL]

>but the speed is not infinitely variable.....

IF that was ever a problem, I would just use the throttle. /w3tcompact/icons/smile.gif

After driving an old Massey with 6 wide spaced gears and then going to a new Kubota with 8 close spaced gears (forward and reverse) and all synchronized I have never even thought about needing a speed corresponding to 1/2 gear speed. If I had a creeper set of gears (4 slower gears), I would use them sometimes with a tiller, but I do ok in first gear and PTO 540 speed running all day. For mowing, I just run in the highest speed that doesn't bounce the tractor around. /w3tcompact/icons/smile.gif

 

[Anonymous Poster]

PaulB, yes it would be, but why do I need to do all three? Just hitting the clutch is enough, or just throwing one of the two levers into neutral which doesn't require the clutch would be enough. Not to mention that with 2 legs and 2 hands I can do all at once. I've gotten myself in a few hairy situations, so I can appreciate the ability to stop quick. I usually run at a slower pace than a real "operator" so maybe I've been fortunate so far because of that.

 

[Peter]

I forget who in the above conversation questioned SAFETY with a gear transmission, but consider you have come to a stop, in gear, with the clutch in, if your foot ever slips off the clutch, you may to through your barn, run over/kill your kid, run into a hole/flip over, etc. Or when you think you're shifted back to neutral but you are not (you know, working fast, doing some back and forth repetetive thing), you let the clutch out thinking you are back in neutral. At least in a car, when you pop the clutch by mistake, the throttle is sprung back to idle and you stall out. Not so with a tractor running at 2000 rpms. HSTs are MUCH safer due to this fact. It always goes back to neutral when you take your foot off it.

I've been using my loader to fill up my truck. I can creap up to within an inch of the wheel-well without worry. With a gear transmission and a little slip, big OUCH.

And installing the back hoe or other implement, you can stand next to the tractor, push the HST peddle with your finger and move the tractor an inch at a time. HSTs rule unless plow fields all day long.

Again, the archives have these arguements and many more.

 

[W5FL]

Tractors are indeed dangerous pieces of machinery. /w3tcompact/icons/frown.gif But they enable many of us to do jobs that would be even more dangerous or impossible without them.

Although I do not agree with you that hydro's are any safer than gear transmissions, but if you are right, then they should make all tractors with hydros as we need all the help we can get in making these machines safer.

My truck is a standard shift, my Honda is a standard shift and my Tractor is a gear tractor, and fortunately I have not had any of those things happen to me, yet, although I am aware that they could.

My tractor is extremely useful because it it heavy, very strong, transmits tremendous energy through the PTO, and can lift thousands of pounds, cut heavy brush, and move or till large amounts of soil very quickly. All those things that make it very useful can also make it dangerous.

 

[Anonymous Poster]

Both HST & GST propel the tractor by the same method.
GST (like an old camera F-Stop setting) has 8 preset size holes through which the fluid is forced, causing 8 different speeds.
HST has a multiple size opening controlled by the foot petal giving many other size hole opening, and so other speeds available.

I have A L3600GST (I got it used with less than 50hr at a good deal).

If I was buying new(which I almost NEVER do) I would certainly entertain the HST.

However Having the preset speeds, I know when hogging up close to a fence 5th gear just a tad to quick, 4th
is just right. No guess work, just alot of cut grass.

Good Luck/Have Fun

 

[W5FL]

Does a GST have a clutch? If so, what does it do?

 

[Bird]

wen, I'm sure I've driven more miles in manual transmission cars and trucks than in automatics, and I know I've put more hours on manual transmission tractors than hydrostatics (never operated a GST, and I've only baled just a few bales of hay with a John Deere powershift). And I'm not afraid to operate any of them with the experience I've had. I figure "safety" is a relative matter. And I don't think anyone is saying that the manual transmissions are too dangerous to use, but I also don't see how anyone could not consider the hydrostatic to be just a little bit safer. Generally all you have to do is lift your foot (or toe) off the pedal to stop; no movement even to the brake in most cases, no need to move the left foot at all, no possibility of your foot slipping off the clutch and having the machine lurch forward or backward, etc.

As far as making all tractors with hydros; I wish!/w3tcompact/icons/smile.gif And of course, we could require all cars to have anti-lock brakes, roll bars, air bags . . .where would we stop?

Like you said, they're all dangerous; just a matter of degrees. So, if everything else is equal, then I'd still say the hydro is safer than the manual transmission, especially for new operators.

Bird

 

[Anonymous Poster]

I suppose if you WERE running your tractor at 2000rpm and you were right next to something and your foot slipped off the clutch (my feet are only size 9 and I can't recall this happening) you probably deserve to run through your barn wall. I never have my tractor at anything above an idle and certainly don't have the hand throttle yanked on when I'm ANYWHERE NEAR anything. I use the throttle pedal which also returns pretty quick. The easy creeping is a plus I'll agree. I park my BX in a space about 3 inches wider and longer than the tractor. Wouldn't try that with the L35! I'm all for an HST IF AND ONLY IF they come out with a good way to use the brakes and the HST (can you say JD?) AND have an adjustment to control the "stop" rate when you take your foot off the pedal, AND a much simpler pull lever cruise control which will work as easy as the hand throttle on the GST. But WHICHEVER any of us prefers, the GST or the HST and the Kubota itself is so far ahead of what I used for 17 years, not to mention what came before that, it's like complaining about the shade of paint on the tractor. Just grab your pick and shovel and go work for 10 minutes! UGH

 

[Anonymous Poster]

On my L35, (GST) the clutch pedal is there so the tractor will be balanced and not tip over for the lack of another pedal...or so it seems. Actually I think it is there for us gear heads to use so we won't go insane at shifting without it, until we try a few times and see that it really does go into reverse without hitting the clutch pedal. That took me awhile to start doing. I'll have to take a look, maybe the pedal isn't actually connected to anything! In reality, it is used to stop the PTO I think, and of course for us who drive stick cars all day and other stick tractors it is there to stop the tractor if you feel more comfortable doing that then operating one of the levers. The lever that is by my hip you just pull straight back into neutral, no H pattern to have to guess at in an emergency.