what are the advantages of glide shift?

[rywen]

currently i have an international 284 and im looking to buy a new kubota. primarialy this tractor will be used for mowing 11 acres of land, but also occasionally used w/ a rear scraper blade. i get by just fine w/ my non synchro transmission on the 284 but im not sure what transmission to get in the new tractor. i see all the advantages of the hydrostatic transmission, but one dealer i spoke with recommended the glide shift transmission since most of the work will be mowing at a constant speed. (but i understand the hydrostatic comes w/ a 'cruise control'). can someone tell me what the advantages of the glide shift would be (if any) ? i suspect its slightly more efficient, possibly less maintenance than hydro? but i havent read about any real problems w/ hydrostatic transmissions so i dont see that being a problem.

 

[RichNJKubota]

I looked at the different types of trans and bought a HST. Heard the same argument that mowing, etc would all be done at the same speed. However, that's not entirely true. When mowing I find I am slowing down and speeding up depending on the terrain and the thickness of the grass. It's nice being able to change the speed of the tractor and have the mower remain at the same RPMs.

Rich

 

[rywen]

right i agree.. thicker grass, diferent terrain. changing speed is helpful sometimes. although from my understanding i could just shift down a gear w/ gst if i wanted to change speed.. but are there any advantages of the gst at all? other than price diference? (i assume gst is cheaper than hydrostatic but i don't remember offhand)

 

[rdam]

I don't know much about the GST. but I do know it's electronically controlled. The literature says "12 forward and 8 reverse clutchless, shift-on-the-go gears using only one lever". Maybe they could call it a "semi-automatic".

I don't even know if it HAS a clutch.

Too fancy for me... I ordered a FST; 8x8 shuttle shift. Far more luxurious than my former 8x2 non-synchro Yanmar.

Rich. I did NOT know you could change speeds and maintain engine RPM with the HST. That is certainly advantageous.

 

[Richard]

In my opinion, one DISadvantage of a GST is if you are on hills.

I rented a L-35 (TLB) once and I'm on hills. I learned the hard way /forums/images/graemlins/crazy.gif that when you change gears while on a hill, the machine (that one anyway) freewheeled as the transmission made the change from X gear to Y gear.

Though the gear change wasn't "slow", it took long enough to scare the bloopers outta me the first time it happened and I was freewheeling backwards down the hill.

Your profile doesn't state your terrain...but if it were ME, *and you were on hills* GST would not even be an option.

It might however, work perfectly for you in your situation.

Richard

 

[Bird]

</font><font color="blue" class="small">( I did NOT know you could change speeds and maintain engine RPM with the HST )</font>

You can not only change speeds as frequently as you wish, but you can stop, back up, go forward again, etc. without ever changing the engine RPM, or shifting a lever, or using a clutch. Just step down more or let up a bit on the one pedal to change speeds or stop and step on the other pedal to change directions.

 

[_RaT_]

I have often heard that becasue of the lag time with GST, folks on hills get a special treat when shifting the GST type transmission. What I don't understand is how a FST or other manuals are any different. On either you can easily depress the brakes to accomodate a shift. Perhaps those with GST are so accustom to not using the brakes for shifting that the thought rarely enters their head. The glide shift transmission is very slick and easy. Shifting from one gear to the other is now almost automatic. That being said, I hear the argument for HST is that folks don't want to do all that shifting, frankly, on my manual tractor, I pretty much find a gear and stick with it. I'm not running through gears like a truck or car. I can easily mow in 4th or 5th on my manual. I start in 4th gear and keep it in fourth. Is this a practice unique to me? Now with loader work, it's another story, on a L4850, I typically use 4th for manuvering and drop into second for burying into a pile. On GST, that is very fast, on FST (L4850)it's a bit slower. On either, using the shuttle for reverse is a snap. So why did I buy HST on my L3830 you might wonder? For mowing, depending on terrain, HST can have big advantages. I have plenty of small ruts that would jarr you apart if you did not slow down. That is one of the beauties of HST. Speed response is nearly instant. The feel you develop using HST is quickly learned to accomodate the rougher terrain. I find that my mowing speed varies throughout the course of mowing from about 2 mph to as fast as 5 mph. All that is easily done on HST without any shifting. For my pond bank mowing work which has very steep banks and would eat a tractor alive if it went in, the HST is truely a work of art, I can't think of a better, safer way to tackle the job. The instant forward/reverse ability plus the HST ability to "almost" lock up the tractor when in the neutral position is a gigantic benefit.

I look at each tranmissions benefits like this.

FST
1. time proven gear design
2. less cost
3. shuttle is very nice, makes F/R a snap, a real bonus for loader work
4. more efficient transfer of HP compared to HST
5. less heat generated
6. full ability to operate differential braking

GST
1. most of the benefits of FST but a little more costly
2. the L30's use electric solenoids now to speed up gear changes
3. snap to use

HST
1. while not "time proven", reliability from 3 Kubota dealers say they have not had failures period. I'm on my 2nd HST tractor, both have been flawless.
2. instant speed response, slow to fast, fast to slow and everything in between.
3. nearly instant forward/reverse
4. the need for brakes is almost eliminated. In neutral, the HST almost locks the tractor.
5. constant PTO RPM while changing speed. IE, in medium, I can go from 0 mph to 7.5 mph and every imaginable speed in between. Since I rarely mow at PTO speed, medium is probably closer to 0 to 6 mph.
6. Super for loader work, least amount of jarring to the tractor and operator.
7. Even though HST still uses a clutch, it is rarely used and the likelyhood of it ever wearing out is not very likely.

I'm sure there are many more positive aspects for all transmission types, all are excellent transmissions. Any one will fill your needs well. Todays shuttles are a great improvement over the manual F/R shift and for many folks is quite adequate. That includes the GST. As more electrical is introduced though as is the case with GST, just be aware you may someday face a situation where you can't shift if a solenoid does not operate be it a shorted wire, a open wire or a bad solenoid until it is repaired. Perhaps that has all been well designed and will never be a issue. Talk it over with the dealer. Neither HST or FST use electrical componets to shift. Whatever you decide, no transmission is a mistake, just different, Rat...

P.S. I have in addition to my Kubota L3830, an International 454. While big and powerful, I much, much prefer the L3830.

 

[jcollins]

One addition to the benifits is that on the new L30 series you can program the GST to shift faster or slower to fit your needs. So that if you have a lot of hills you can prgram the transmission to shift very quickly to avoid the roll back problem someone had mentioned earlier.

 

[DK35vince]

Rat,
Very nicely done !!
That is the best breakdown of the transmission types I have seen on this site so far. /forums/images/graemlins/cool.gif

 

[DK35vince]

</font><font color="blue" class="small">( I hear the argument for HST is that folks don't want to do all that shifting, frankly, on my manual tractor, I pretty much find a gear and stick with it. I'm not running through gears like a truck or car. I can easily mow in 4th or 5th on my manual. I start in 4th gear and keep it in fourth. Is this a practice unique to me? )</font>

No its not unique to you.
Once I begin mowing my field or lawn (15 acres total) I very seldom shift a gear