Manual vs Hydro Transmissions

[SOS]

I'm purchasing a NH 45 this weekend but I had one more question before I do. What are the advantage and disadvantages of a manual & Hydro trans?

From what I've read,

Hydro's are more expensive (around $1,800) and have more potential for parts to break. Do they cost more to fix? How long do they last?

Manual's are cheaper but the cluch will eventually wareout and cost me 1,800 to replace. How long should a clutch last under moderate to light use?

I plan on keeping the tractor for 15 years so I could use your help.

 

[RFB]

http://www.tractorbynet.com/forums/...0-55hp-cut-utility-tractor-4.html#post1049422

http://www.tractorbynet.com/forums/...0-55hp-cut-utility-tractor-5.html#post1049617

 

[Glowplug]

The way I look at it is simple. I do have a lawn tractor with HST and I have driven and soon will be purchasing a tractor with standard shift transmission but I don't have a ton of hours on that type of transmission.
HST is good for frequent directional changes such as for FEL work or when mowing and changing directions around obstacles. Standard shift is good for mowing straight-aways and with ground-engaging activities such as plowing and discing. HST is often found on CUT. Standard geared transmissions are found almost exclusively on utility tractors and agricultural tractors. In other words, you would be hard pressed to find a tractor much over 50hp that has a HST. HST is more complex. Just think about how it works. If it breaks I would imagine it would be very costly to fix. There is some loss of power from the engine to the PTO as far as hp goes with HST. But HST is very easy to learn for those who have never operated a tractor before. There probably is a bit of a learning curve with standard shift transmission. But there is a reason it is on ALL the larger tractors. They both have their advantages and disadvantages. You just have to think about what you feel comfortable with, what type of tractor you will be buying, and what type of work you will be doing.

 

[dirtworksequip]

Currently I own both. JD 870 w/ standard trans and a JD 3520 eHydro. The standard will give you rugged,simple service. Plus more to the ground power for the same hp. Also probably cost less to repair over the long run. I have not had any problems or repairs with the standard transmission or clutch. The 870 is 12 years old with 2090 hours.

The ehydro although fairly new I beleive may have more long term problems just because of the complexity of the transmission and electrical system. It may not be a mechanical problem, but electrical failure.

I run heavy equipment for a living and have worked with many big name excavating companys.I also own a couple pieces of my own. 9 times out of 10 breakdowns on the newer pieces are electrical and not mechanical. It takes some serious diagnostic head scratching sometimes to trace down the problem.

It all comes down to what do you want. Rugged dependability (geared)or ease of operation and convience. (hydro) Geared tractors are not any harder to learn to operate, they just take a lilttle more hand and leg movement.

 

[RalphVa]

Read the links posted above. There has been LOTS for discussion on these in the past.

If you do most of your work running the tractor across big fields, a geared transmission will save a little bit of fuel in not wasting so much heat to the transmission/hydraulic fluid. For most other work, HST is so convenient and safer on hills, etc. HST is what is used on air craft and ships. It's very reliable, probably more so than the geared unit with clutch.

My neighbor's old geared JD that's about 1975ish vintage had its clutch go out a couple years ago. The clutch in my 1983 Benz with a little over 200k miles on it is still original. It'd think, that clutches should last until engine overhaul is needed in both tractors and cars as long as they're used properly. However, clutch replacement in a tractor entails another whole lot of work to do in addition to engine work, not like on a car where you'd probably remove the engine and could easily do the clutch.

I have nothing but geared pickup and cars and have only ever owned one automatic transmission car (not same as HST), but for tractor work I like HST. However, if I had big fields to plow or to cultivate, I'd get a gear tractor.

There are shuttle shift units out there. Not sure how they work mechanically but could offer advantages of both gear and HST and probably be equally as long lasting.


Ralph

 

[MossRoad]

It would be helpful if you posted what types of chores you plan to do with this tractor.

For example, if you are going to be plowing fields primarily with this tractor, gears would make more sense. If you are going to be doing FEL work or mowing odd shaped areas, hydro would make more sense.

 

[Z-Michigan]

I think it's well summarized above. I'm currently shopping and have driven a number of tractors of both types. It really depends on what you want to do and how comfortable you are driving a stick shift. Basically if you're experienced driving manual and you're not going to do tons of loader work, the gear will save money and fuel. But the HST is more convenient, much easier if you haven't driven stick shift before, and allows really precise control at low speeds which is much more difficult with the manual shift. My tractor plans are a mix of each type of use and I'm still debating which one makes the most sense for me.

Shuttle shift goes along with a conventional manual transmission. Basically it's a separate lever that is used only to choose between forward and reverse, and it's usually mounted on the left side of the steering column. Let's you change directions without moving your hand all the way to a gearshift somewhere else.

I have done a lot of direction-changing testing with both types of transmission. I find that there is no speed advantage to HST, but it does require only one movement (your right foot to a different pedal [or other end of the same pedal on Kubota]) vs. having to use throttle, clutch and shuttle lever on a gear transmission.

On bigger tractors (not the TC45, but at the TC55 and up) there is often a "power shift" feature which combines a manual gearbox with a electro-hydraulic clutch and allows you to move the shuttle lever without pushing the clutch. Very convenient, though not any more convenient than HST.

One other significant difference is that on HST, if you take your feet off the pedals the tractor will come to a stop pretty quickly. On gear drive the tractor will keep moving until you push in the clutch and apply brakes. This could be a useful safety benefit if the tractor will be driven by someone who is easily distracted or easily confused about how to stop the tractor. The flip side is that with HST you have to keep your foot down to keep moving, unless you apply the cruise control feature (which is very common on HST tractors).

By the way, HST has been around for several decades and is pretty well proven technology; it just costs more and uses a bit more fuel.

The NH TC45 is pretty close to the top of my list right now, so I don't think you can go wrong with that one.

 

[Glowplug]

It'd think, that clutches should last until engine overhaul is needed in both tractors and cars as long as they're used properly. However, clutch replacement in a tractor entails another whole lot of work to do in addition to engine work, not like on a car where you'd probably remove the engine and could easily do the clutch.

You'd think that. But I've heard of guys burning up clutches in tractors every few years. Of course, these are people who abuse them. They do heavy extensive loader work, don't clutch appropriately, and run in high gear. If a clutch is used appropriately it should last quite a while, hopefully the life of the engine. I find it kind of hard to believe that a new clutch for a geared standard transmission would run $1800. But it may be true.

On bigger tractors (not the TC45, but at the TC55 and up) there is often a "power shift" feature which combines a manual gearbox with a electro-hydraulic clutch and allows you to move the shuttle lever without pushing the clutch. Very convenient, though not any more convenient than HST.

That's my understanding of what Kubota's glide-shift transmission basically is.

 

[jk96]

I find that there is no speed advantage to HST, but it does require only one movement (your right foot to a different pedal [or other end of the same pedal on Kubota]) vs. having to use throttle, clutch and shuttle lever on a gear transmission.

Z, I just don't know if I agree. I've operated both, but I went with HST on my tractor because 60-70% of my usage is for mowing with lots and lots of trees, some tight spaces, etc. With as much slowing, stopping, reversing, etc that I do when I mow I just can't imagine a gear being just as fast as my HST. I guess its possible but it wouldn't be easy or fun, it would be a real pain in the ....... I'd look like a dang monkey on crack out there trying to change gears, throttle, speed, clutch etc if I was going to keep moving at the same pace. As everyone already pointed out, type of usage is key.

 

[Z-Michigan]

Z, I just don't know if I agree. I've operated both, but I went with HST on my tractor because 60-70% of my usage is for mowing with lots and lots of trees, some tight spaces, etc. With as much slowing, stopping, reversing, etc that I do when I mow I just can't imagine a gear being just as fast as my HST. I guess its possible but it wouldn't be easy or fun, it would be a real pain in the ....... I'd look like a dang monkey on crack out there trying to change gears, throttle, speed, clutch etc if I was going to keep moving at the same pace. As everyone already pointed out, type of usage is key.

All I can say is your mileage may vary... I learned to drive on stick and have many tens of thousands of miles on manual shift cars and motorcycles. I can manipulate all three controls very fast, faster than I can usually move my right foot between two different pedals. Of course it is A LOT more work and would not be my choice if I were going to do a lot of loader work or mowing in really tight areas. So much so that I'm leaning towards an HST for my own tractor even though I can use the gear no problem.

I'm really interested in the issue of clutch life with gear transmissions... if my loader work and tight-area mowing is going to wear out clutches every three years, that tilts it heavily toward HST for me. If it's not going to wear out the clutch, then it's neutral for me, and the cost and fuel use differences seem more significant.