[rlordjr]

As I have been surveying the domain of garden tractors with my newfound license to "get a better tractor" it seems like 2 paths have been taken.

For example, all of the heavy duty JD machines seem to have front and rear hydraulics for hooking up pressure-powered implements. Nifty.

But our Gravely's and some others continue with the "direct drive" using PTO's and such. Granted some of the JD's have both and the larger tractors have your basic 3pt hitch and rear pto for "real" farming.

Seems like the "modern" equivalent would be a drivable electric generator (see the Raven at Lowe's) to power electric implements, but that's another topic.

Here's my real questions: Are hydro-driven implements lighter or easier to work with than mechanically driven ones? Are they more expensive because of the high-pressure hoses, seals, etc.?

Just seems like it would be cool to have a machine with a really robust hydraulic system and then implements that literally "plugged in" to get power.:dunno:

 

[Richard-tx]

The advantage to hydraulic implements is the flexibility in mounting. The disadvantage is the maintenance. Hydraulic filters are not cheap. Neither are pumps or motors. Some hoses can be costly too.

Nothing is perfect. Everything is a trade-off.

 

[CADplans]

Hydraulics throw 20% of the horsepower out the window (into heat!! :duh.

Plan on 20% larger engine than a gear drive equivalent to do the same job.

Oh, yea, 20% more fuel consumption.

That said, hydraulics are REAL convenient, there are tradeoffs in life. :dunno:

Use the right tool for the right job. JMHO

 

[braxx]

I have Case/Ingersoll GT's and they are hydraulic driven and can have a rear hydraulic PTO (It is a hydraulic port to supply hydraulic pressure) to run a rototiller, powered lawn clipping bagger, log splitter, pull behind finish mower and a pull behind brush hog.
Driven off of a belt is a mid mount bower or a front snow blower.
Also a rear hydraulic 3pt can be added/used.
I like the setup. No belts or clutches to adjust or break in the driveline.
Plus infinate speed control from 0-8mph. You can slowdown or speed up without changing throttle or having to pick a different gear.

 

[arcam8123]

I have a friend that traded a Gravely 8179 with a rear tiller for a Case with a hydraulic rear tiller. He regrets it to this day.

 

[TUDOR]

For example, all of the heavy duty JD machines seem to have front and rear hydraulics for hooking up pressure-powered implements. Nifty.

Here's my real questions: Are hydro-driven implements lighter or easier to work with than mechanically driven ones? Are they more expensive because of the high-pressure hoses, seals, etc.?

Just seems like it would be cool to have a machine with a really robust hydraulic system and then implements that literally "plugged in" to get power.:dunno:

Most of the hydraulic remotes on JD tractors are for the cylinders required for implement use, eg. lifting and turning front mount plows or 3PH back blades. Only a few models have sufficient flow to use for powered implements such as a tiller.

Implements driven with PTO shafts can also be driven with hydraulics. There is little difference in implement weight or strength for hydraulic powered implements over the same implement driven by a shaft.

The price for hydraulic power is not cheap. Pumps, motors, valves, and hoses are precision made and costly. The advantage is that they last a long time with minimal maintenance if quality components are used. There are many hydraulic problems being discussed on MTF at any given time. Most of them are on tractors that are 20, 30, 40, and more years old, and usually caused by contaminents in the system and the normal wear and tear caused by hundreds, if not thousands, of hours of use. Most have the original components, including hoses, still in service.

As has been mentioned, there is a minimum of 20% horsepower penalty involved with using hydraulics. This can be partially balanced against the minimum of 10% horsepower penalty paid to reduce engine rpm to PTO rpm and delivering that power to the implement. Actual horsepower loss is dependant on actual horsepower used, not the horsepower that the engine is capable of producing, thus fuel consumption is not really much higher.

The biggest advantage of using hydraulics, besides convenience, is that the maximum torque available is independant of the engine's output. A hydraulic motor produces the same maximum torque whether the engine is at idle or full throttle, only the horsepower numbers change. A PTO is reliant on the engine output for its torque availability. That is considerably lower at idle than at full throttle.

Depending on the filter involved, most do not cost more than 2 or 3 times the cost of a quality filter for your truck. Changing the oil in the system can get a little pricey, depending on the reservoir capacity. Oil and filter change intervals are in the area of 100 - 300 hours of use.

Getting the right combination of pump and motor can be a mathematical chore. There are several variables involved.

 

[TexasT]

But our Gravely's and some others continue with the "direct drive" using PTO's and such. Granted some of the JD's have both and the larger tractors have your basic 3pt hitch and rear pto for "real" farming.

Another point to think about is that the Gravely G tractor has its roots in a design that is 45 years old. The 450 used an electric lift. Hydraulics then were for REAL farm tractors and the scaling it down for lawn and garden tractors hadn't really happened.

Technology has come a long way, just look at what can be done with the Zero turn. Those sunstrand pumps from the seventies had a pretty finite life and many were cut short by lack of maintenance. Simplicity did pretty good with them to drive their hydrostatic tractor but to size it up to run implements got pricey. Small tractors are a very competitive market, the one you're selling cant cost twice what the other guys does.

I never understood with the great strides in pumps and such, why Gravely didn't go to a completely hydraulic two wheel tractor. Engine, pump, filters reservoir, wheel motors and a hydraulic pto. They could have set it up to run the old attachments. Seemed like a no brainer but I guess no one wants to walk behind any more.

After having my 1066 Farmall, 125 pto hp is hard to beat. But it didn't groom or get into tight places like a walkbehind.

 

[coldone]

I am not sure of what you are asking. The only Gt that has hydro powered implements are the Case GTs. That system is a hydraulic pump directly mounted to the engine. All others tap into the hydrostaic system to get their power from the hydro. The Hydro taped system usually just run the lifts not the implements. The implements are powered from a mechanical PTO through belts and shafts. If you are planning on running a tiller I would sugest that you look for a GT that uses a belt to drive the tiller. The PTO pwered ones run at 2000rpm PTO speed and are hard to find plus expensive when found. Belt powered ones can be found easily.

 

[PA RedRider]

I looked at the Case/Ingersoll/Eastman tractors. They're nice. Two things I considered at the time were:

1. I had heard the hydro-drive's have a mind of their own when going down hill;
2. I have an aversion to belt-driven mower decks.

To repeat what Ron already said, I doubt a Case/Ingersoll rear tiller could hold a candle to the Gravely shaft driven rear-mounted tiller. I own the latter and have used it for two years now. It does an outstanding job.

If my wife gave me the green light (and money was no object), there would be a BX2660 in the garage. Very easy decision after many years of looking.

 

[rlordjr]

I'd also be going for a Kubota BX setup if I weren't too cheap to sink that kind of money into a yard and gardening machine. Heck, my Grand Cherokee only cost me $7k!