Transmission Durability: GST vs Hydro

LittleBear · Jun 24, 2005

I am looking at the Grand L5030. Which transmission (GST or Hydro) will generally last the longest without needing repairs? For example, I know a wet clutch will outlast a dry clutch. Are there any similar generalizations with these transmissions?

Dargo · Jun 24, 2005

Odds are very strong that either will outlast how long you will keep the tractor; even if that is a very long time. I really had no preference between the two when I went to drive them. Since I do a bit of loader work, I gave the very slight edge to the HST, and bought my L5030HSTC.

Either transmission is good, and you can't go wrong. As far as durability, most every heavy dozer uses a hydro type of transmission for heavy ground contact work. I'm yet to see a gear dozer. They don't seem to have issues. I think it really should be a matter of your own personal preference.

AntrimMan · Jun 25, 2005

Stop looking and make the plunge. You will not hate the HST, it is more versatile IMHO. True, there will be some failures of each type of tranny. I have an old hydro '72 Wheel Horse, always rode hard and put away wet, and she still goes good, the hydro part has never given trouble. Kubota has their act together too. Some times I find myself negotiating backwards up looonnnng sttteeeep wooded slopes while kneeling on the operators seat with one knee and using the other foot on the HST treadle, yeah I know the tractor police will pay me a visit now that the cat is out of the bag, I can't imagine doing this with a clutch. The HST is one heck of a good brake too.
Make sure the HST fits your needs, buy the machine, whip the heck out of it and pm me to tell me I'm correct when you can't break it or the kleenex are on me. Big smile.
Best of luck,
Martin

texbaylea · Jun 25, 2005

I have the HST and love it. Wouldn't go any other way. My opinion is that the transmissions are equally rugged however My greatest concern about the GST was the switches and solenoids the control the shifting. In my mind this is the weakest spot of the GST

Vernon

tralderman · Jun 25, 2005

From a dealers perspective, we do not see more failures one way or the other. We have seen used HST and GST transmissions that are 15 - 20 years old that still perform like new.

A GST gives you a little more oomph but not enough to really make a difference. However, the HST is easier to use and can be somewhat safer to operate for the novice.

Don't buy one over the other because you are concerned with durability. Buy the transmission that suits your needs best and is the easiest for all those who will be operating it.

- Tim Alderman
Alderman's Inc.

Rick_Morrell · Jun 26, 2005

Dargo:

"As far as durability, most every heavy dozer uses a hydro type of transmission for heavy ground contact work. I'm yet to see a gear dozer."

Actually, the reverse is true for heavy-duty track-type tractors. Once you get above the 300 hp class (Cat D8, Deere 1050, Komatsu 155 - heavy construction, but still construction) then you're pretty much getting an electronic powershift transmission (similar in principle to the GST) which is an electronically-controlled gear transmission. Like loader tractors, the hydrostatic transmission in a track-type tractor shines for enabling a bulky machine to be nimble, allowing better control in fine grading operations.

I have an L3130 with a GST. I like it because I was accustomed to the powershift transmissions found in construction and mining equipment, and it had fewer parasitic losses than the HST. As far as durability goes, I would venture to guess the HST may be a little more bullet-proof simply because it doesn't have solenoids like the GST (no doubt a large MTBF, but still an electronic gadget).

Rick

SkyPup · Jun 27, 2005

I have two GST's and a Hydro, they all work extremely well for what they are intended to be use for.

Dargo · Jun 27, 2005

( Once you get above the 300 hp class (Cat D8, Deere 1050, Komatsu 155 - heavy construction, but still construction) then you're pretty much getting an electronic powershift transmission (similar in principle to the GST) which is an electronically-controlled gear transmission. )

Yes. I worked helping rebuild part of a D11R dozer that went down. No, I wasn't the chief mechanic nor the "brains" behind the job. I was a "gofer". However, I did get to see how it was built. Cool! Everything is like supersized. Heck, it even had all sorts of GPS stuff on it. /forums/images/graemlins/shocked.gif

Anyway, you're right on that. After seeing one up close and personal, it looks more like a GST or electric shuttle shift sort of a setup. It was nothing like the Cat 955 I once owned. Unfortunately for me, the Cat I had apparently had been ran hard and put to bed wet many times before I ever got it. Oh well, you live and learn. I now know more about that thing and the 450 Case high lift than I ever wanted to know! /forums/images/graemlins/blush.gif

Rick_Morrell · Jun 27, 2005

Dargo:

Too bad about that 955. That's a neat piece of equipment. It's a shame when someone doesn't take care of their tools.

 ( Heck, it even had all sorts of GPS stuff on it. ) 

Sounds like your D11 was equipped with CAES or a like gadget (LCD monitor on the dash?). That's a popular option for overburden removal in a coal mining operation. They're quite a piece of machinery.

Rick