Hydrostatic trasnsmission vs. gear drive

[Hermio]

Many forums have discussed the transmissions available: gear, shuttle or hydrostatic. One point that I have not seen mentioned is safety. With any gear drive tractor, if you get into a situation where the tractor is apt to flip over or roll over, you must rapidly find the clutch and disengage it before the rollover occurs. The whole process may take less than a second, and you have to find the clutch while you are in the process of being tossed about on the seat, or maybe even tossed out if you are not wearing a seatbelt. With a hydrostatic drive, all you have to do is stop pushing down on the HST pedal, and it will stop almost instantly. If you lift or drag heavy loads on slopes or in woods, this can save your life. Unless all you do is flat work with no heavy pulling loads, you should seriously consider an HST model. By the way, the lower theoretical efficiency of an HST drive is often made up for in mowing or similar applications by being able to speed up or slow down as the load changes, whereas with gear drive tractors, one tends to stay in a gear selected to let the tractor do the job in the toughest areas, and then not work as fast or as hard in the easy areas.

 

[DK35vince]

Many forums have discussed the transmissions available: gear, shuttle or hydrostatic. One point that I have not seen mentioned is safety. With any gear drive tractor, if you get into a situation where the tractor is apt to flip over or roll over, you must rapidly find the clutch and disengage it before the rollover occurs. The whole process may take less than a second, and you have to find the clutch while you are in the process of being tossed about on the seat, or maybe even tossed out if you are not wearing a seatbelt.

I've been running manual/gear transmissions for nearly 40 years and have no idea what you are talking about.

 

[Gary Fowler]

As with everything, safety involves knowing your equipment & being proficient in operation. It makes no difference whether it is HST or gear, if the operator doesn't know how to safely operate it, he is not safe. In an impending roll over, a real one-not a "I think I might be in trouble" type, the last thing you would be thinking of is pushing in the clutch OR taking your foot off the HST pedal. When a real rollover occurs, it is so fast that you don't have any time to react to anything. THE ONLY safe thing to do is plan your work and think ahead so you don't get into an emergency situation. Failure to engage the brain before getting on a piece of equipment is what causes 99.99% of accidents. The .01% is mechanical failure.

 

[Hermio]

I've been running manual/gear transmissions for nearly 40 years and have no idea what you are talking about.

How much of that has been in the woods? When going into woods that have been logged but have brush grown up, sometimes you cannot see a stump due to the brush, and that is but one of many things that can cause a rollover. Another potential problem is bush hogging a trail one direction, then going back the opposite direction. I did that once and had a downed 2" sapling pop up and get pushed up into the path of my chest. If I had been using a gear drive tractor, the sapling would have run me through. As it was, I just instinctively lifted my foot, which stopped the tractor and merely got severely bruised on my rib cage. (It hurt when I breathed for about a week.). Yes, I have used gear drive tractors in the woods also, but after that kind of incident, I am very leery of them. I prefer to use them only in open spaces where there are no hidden hazards. I am planning to buy a Mahindra 5035 HST when my funds permit. That will replace my similarly-sized Ford 4010, which is on its last legs.

 

[s219]

I guarantee there will be freak accidents where gear/HST will be completely irrelevant, and someone can probably find a scenario where HST would be less safe than gear. To me, this is a bit of a stretch. I certainly don't feel like my geared Deere is less safe than my HST Kubota because of the transmission, same way I don't feel like my manual BMW is less safe than my automatic GMC because of the transmission.

 

[Egon]

I've been running manual/gear transmissions for nearly 40 years and have no idea what you are talking about.

I've been pushing in clutch pedals for over sixty years. I know what the OP is talking about.

 

[Hermio]

I guarantee there will be freak accidents where gear/HST will be completely irrelevant, and someone can probably find a scenario where HST would be less safe than gear. To me, this is a bit of a stretch. I certainly don't feel like my geared Deere is less safe than my HST Kubota because of the transmission, same way I don't feel like my manual BMW is less safe than my automatic GMC because of the transmission.

Not really a valid analogy. To stop a car, you must use the brakes whether you have a manual or automatic transmission, so there is no difference in safety. To stop a rollover that might be caused by hitting an unseen object, you just have to stop delivering power to the axle. As a bonus, when you stop pressing the hydrostat pedal, you also get braking action.

In my case, I am alive today because of the hydrostat transmission on my Kubota, as I described previously.

Another aside: a hydrostatic transmission is NOT an automatic transmission. There is nothing automatic about it. It is fully manually controlled. It is just an infinitely variable transmission.

 

[ruffdog]

I have seen some instant pro's do some dumb things on easy to drive HST's but also have seen bad things happen on old geared units. The tractor doesn't do stupid, the operator does. Give the same people that do strange things on a tractor a chainsaw and see what happens.

 

[Hermio]

I've been pushing in clutch pedals for over sixty years. I know what the OP is talking about.

I, too, have been pushing clutch pedals for more than a few years-45 to be exact. I learned to drive with a manual transmission. So, for me, it is not a matter of skill. Now I will expand on the fuels efficiency angle. If you have a variable terrain you are mowing, with an HST, you will tend to speed up or slow down in response to conditions. With a gear drive tractor, you will tend to keep in whatever gear allows you to operate in the toughest areas without stalling out. That means you could go faster in some areas, but you don't, because you would have to change gears, which means stopping the tractor with a purely manual transmission. Few will do that. Thus, the hydrostat saves time and is more efficient in such cases. It also lets you use a smaller tractor. My Kubota happens to be 16 Hp (about 12 PTO Hp.) Yet I have had no trouble running it with a 60" finishing mower, a 4' bush hog, and a 50" rototiller. The 5 Hp per foot of Bush hog width would suggest I needed 20 PTO Hp for my bush hog, or at least 25 engine Hp. But with the HST, I can slow down easily when needed, and speed up when possible. My Ford 4110 is rated at 54 engine Hp. I run it in 6th gear (out of 8) when using a 6' bush hog. I could run it faster in some places, but it would stall in a higher gear in really heavy grass, or when mowing down small saplings. So, I keep it in 6th gear.

 

[Hermio]

I have seen some instant pro's do some dumb things on easy to drive HST's but also have seen bad things happen on old geared units. The tractor doesn't do stupid, the operator does. Give the same people that do strange things on a tractor a chainsaw and see what happens.

While it is true that most accidents are caused by operator stupidity, what we are talking about here is intrinsic machine safety. I maintain that in the woods, an HST transmission is intrinsically safer than gear drive. That does not mean that accidents will never happen with one. It just decreases the odds.