Why no hydrostatic transmissions on larger tractors?

[Sawyer Rob]

Mainly because of the heat generated, the noise, the inefficiency, and short lives.
More horsepower aggravates and increases all of the above.

That's the long and the short of it right there!

SR

 

[ptsg]

I’m not sure about reliability being a factor. My dealer’s service manager told me they replace far more clutches on gear tractors than they see HST problems.

Not surprising considering that US and a simple clutch don't go very well together. At least for most people.

Around here, it's not uncommon at all to get anywhere from 3000 to 4000 hours on a clutch. Some more, some less, depending on the type of work and the operator of course.

 

[MinnesotaEric]

Not surprising considering that US and a simple clutch don't go very well together. At least for most people.

Around here, it's not uncommon at all to get anywhere from 3000 to 4000 hours on a clutch. Some more, some less, depending on the type of work and the operator of course.

Meanwhile, my Payloader has 13,000 hours on its "unreliable" hydraulic transmission. It is on its second D466, arguably the most reliable mid-size, straight-six diesel produced.

 

[ROUSTABOUT]

One they brought to me, I was told it wasn't quite going into reverse. 24speed hydrostatic. I took it down, reverse was not there. Shopping the first three parts had me at 5500 $. Bought another tractor with gear shuttle and swapped shuttle unit over. Much cheaper and much better. I think it was a 1455 Massey Ferguson. Been a few moons. Had a six cylinder Perkins.

 

[ptsg]

Meanwhile, my Payloader has 13,000 hours on its "unreliable" hydraulic transmission. It is on its second D466, arguably the most reliable mid-size, straight-six diesel produced.

Doesn't your machine use a Torque converter coupled to a power shift transmission? As far as the engine, from what I've seen on the internet, those things run forever along with the Cummins 5.9 with just basic maintenance.

 

[MinnesotaEric]

Doesn't your machine use a Torque converter coupled to a power shift transmission? As far as the engine, from what I've seen on the internet, those things run forever along with the Cummins 5.9 with just basic maintenance.

You are correct. Basically the engine runs three hydraulic pumps. One for the transmission, one for the steering, and a big one for the loader, and third function which is rated at 42 gallons a minute or the ability to cycle up and down 31,000 pounds in seven seconds. My machine was made for loading on-road running dump trucks and logging operations.

 

[TMBRWLF]

Meanwhile, my Payloader has 13,000 hours on its "unreliable" hydraulic transmission. It is on its second D466, arguably the most reliable mid-size, straight-six diesel produced.

Great location. Offen went to Nevis in the 60s/70s. Lake Belle Taine. Look up Beauty Bay Lodge. Grand parents build it in 1946...

 

[kfriis]

Meanwhile, my Payloader has 13,000 hours on its "unreliable" hydraulic transmission. It is on its second D466, arguably the most reliable mid-size, straight-six diesel produced.

Don't know about the OM617, huh?

 

[kfriis]

Don't know about the OM617, huh?

.... but since this is a 5, I guess it completely invalidates my comment!

 

[Gord Baker]

Many larger tractors are available with Shuttle feature which gives you Reverse in whatever gear you are in. Very handy in certain circumstances.