What happened to GST?
- Thread starter Jay4200
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crazyal
Super Member
What do you plan on doing with the tractor. Each type, gear, GST, and HST have places they out shine the others and other places that they just don't do as well.
dfkrug
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The Glide-Shift Trans (GST) is one of several gear trannies sold by Kubota,
since the 80s. Some would say it is the ultimate type of gear trannie. What
disadvantages does it have vs. the DT (dual-traction unsynchronized) or
FST (fully-synchronized) gear trannies? The only thing I know of is price.
crazyal
Super Member
Well as you said price. But if you main use for the tractor is something like pulling a plow then DT is probably your best option. Plus it's simple and of the different types it's been around a lot longer.
OP
Jay4200
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I would guess that the disadvantage over DT is slightly more complexity - two clutches, and I believe that straight gear puts more power to the PTO. What does "dual-traction" mean anyway? I don't know what FST does - I'd guess no clutch required but no direction lever? Advantages of GST(and maybe FST?)...what's a clutch? I think I've stepped on mine twice in 5 years. I can see the advantage of HST for loader work though, simply because it would be easier to make the bucket move faster since the motor is revving fast all the time. GST is pretty good for loader work though - way better than gear. The direction lever makes forward to back instant, but I chop the gas when I make that shift - letting off the gas right when I stuff the bucket into a pile makes the lift slow, although I usually manage to curl and lift enough to get a full bucket during the slight engagement pause, so the movement is usually seamless. Personally, I don't like HST - I don't like having the motor scream away while modulating travel speed - it just doesn't register correctly in my brain. My lawn mower is set up that way and I always feel like I'm not quite in control. I definitely like having a gas pedal. I also think I rack up 1/2 the hours on my meter because I only rev the motor when I need extra power (or when I get frustrated). With HST, you pretty much have to run the motor at the RPMs required for your worst-case power scenario all the time. Apparently it's also hard to use the split brakes with HST - I have a friend with a B26 HST who complains about that.
OTOH, if somebody took away my 2500-hour L4200GST and dropped off a new L5040HST, I wouldn't complain. 'Course, if I had to pay for it, I'd probably stick with GST.
JayC
TripleR
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I own and run both HST as well as geared units and my HSTs are not "screaming" all the time as I vary engine RPMs to fit the power needs just as I do on my geared units.
dfkrug
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There are lots of variations on the gear trans theme, and this is just
Kubota. Other big makers offer similar choices with different brand names.
Gear vs. HST is a whole other topic, and there are thousands of lines
written on TBN about that. There is heaps written about GST, too.
Some things to note:
> though Kubota charges more for the GST vs FST, DT, these electro-
hydraulic trannies should go longer without clutch maintenance, since the
foot clutch should be rarely used, and it is a wet-multiplate unit. OTOH,
the others have dry foot clutches that are wear items that will need
replacement and tractor-splitting. The earliest GST I drove was an L2650
of about 1990 vintage, if I recall. I think that even the early ones had
wet foot clutches. Some newer non-GST Kubotas may use wet multiplate
foot clutches, too. I do not know. The GST does have more electric
controls for added complexity, but it has proven reliable. Again, the GST
is 2 thumbs up if your tractor use calls for a gear trans.
> DTs I have owned have either had a dash-mounted fwd-rev shuttle, or
a between-the-legs stick shift. Some shuttles had synchros, some did not.
The between-the-legs stick shift style is simply awful, IMO. I have never
driven a fully synchronized range and shuttle like the FST. Although you
may have the same trans on a rare 2WD Kubota, the DT (dual traction)
seems to mean 4x4. The 2WD version sometimes is designated "F".
crazyal
Super Member
Not sure about some of the other models but the GL40s have auto throttle which only gives it 'gas' when you step on the pedal so you don't need to rev the motor up. Or you can set the hand throttle to a middle RPM, like 1500, to have extra RPMS to make the FEL move faster and have more power and not have to reduce it to shift from forward to reverse. A big advantage of HST for loader work is you don't need to shift, pull a lever, or even let off the throttle. You just simply push the HST pedal in the reverse direction.
Maybe I'm mistaken but I've always associated DT and gear with a standard transmission like a car. It's simple and cheap. The ones I have used were unsyncronized and shifting gears was always a challenge. Even to this day I can still feel the grinding of the gears, lol.
