Buying Advice Done with hydrostatics

[k0ua]

Is that hydrostatic or IVT? I thought everything over 100hp was IVT, but I am sure no transmission expert.
Hydrostatic is easy to use, foot treadles eliminate need to use left arm/hand on reverser. Don't understand why someone hasn't
come up with hydro functionality and high efficiency too. The transmissions in our cars and trucks have become super efficient, up to 10 speeds now. But we seem stuck at a three speed hydro. 3 speeds work nicely for me, btw. I use all three, from tilling and loader work to running down the road in high. Now if they could shut up the whine...……..

Yes, heavy equipment has hydros all over the place and the really heavy stuff now seems to be going diesel electric.
But to the best of my knowledge, JD at 66hp(is it up to 70 now?) in a four series is the most you can get.
Why not a hydro option in a 5? Or a Kubota M?

I have a "one speed" variable hydro on my 1968 Cub Cadet. They've come a long way...

Daugen, the number of "ranges" or "speeds" have nothing to do with the effeciency of the hydro units. Remember the range selector is nothing but a simple non syncronized gear transmission behind the hydro unit. It is not really a part of the hydrostatic transmission, it is just a simple gear transmission for speed/torque adjustment to suit the job and the terrain.

As you know some hydro transmissions are used in heavy equipment where needed. But as the power goes up and the machine gets heavier, the inherent inefficiency of the hydro unit start to add up and the fact that you need higher and higher pressures in the hydro unit for bigger machines adds cost and complexity.

Hydros are great and I sure love mine, but the way we small tractor lovers use our tractors we can spend a few more dollars each year for extra fuel to enjoy all the wonderful characteristics that a hydro brings to the table, But if you are pulling a plow around a field all day with a large tractor the loss of efficiency starts to subtract from the bottom line of the harvest.

 

[WranglerX]

For you K46 owners, TUFF TORQ has a complete line of rebuild parts... Have a 2004, JD L120 and after about 400 hours I was having problems, for about $400 you can do a complete rebuild of K46 transaxle.... TT also recommends 20W50 full synthetic for oil.... Funny part is for about $700 I could have bought a NEW one...

Tuff Torq - Integrated Hydrostatic Transaxle Authority

Parts and service..

Tuff Torq Parts

 

[WranglerX]

There is a rubber plug on the top whereby oil can be sucked out and replaced. Thicker oil seems to be the word from TT. There is a very fine mesh filter screen inside the oil section, in the top of the unit.....about 2" diameter, 1" high.

TUFF TORQ recommends 20W50 full synthetic as oil of choice...

Dale

 

[Groo]

I knew I was getting junk when I purchased it. The problem was I could not afford the step above junk at the time. My plan is to abuse the junk for the span of the 3 year wanranty and hopefully get a new tranny near the end of it. When it goes out while not covered by waranty, my plan is to replace it with a better one, like a K66 or a K72 or a complete machine a step or two better.

 

[Bavarian]

Is that hydrostatic or IVT? I thought everything over 100hp was IVT, but I am sure no transmission expert.
Hydrostatic is easy to use, foot treadles eliminate need to use left arm/hand on reverser. Don't understand why someone hasn't
come up with hydro functionality and high efficiency too. The transmissions in our cars and trucks have become super efficient, up to 10 speeds now. But we seem stuck at a three speed hydro. 3 speeds work nicely for me, btw. I use all three, from tilling and loader work to running down the road in high. Now if they could shut up the whine...……..

Yes, heavy equipment has hydros all over the place and the really heavy stuff now seems to be going diesel electric.
But to the best of my knowledge, JD at 66hp(is it up to 70 now?) in a four series is the most you can get.
Why not a hydro option in a 5? Or a Kubota M?

I have a "one speed" variable hydro on my 1968 Cub Cadet. They've come a long way...

It's hydrostatic. But powered by a variable hydraulic pump. Quite complicated. The smallest they build is rated at 72hp.

 

[IH3444]

TUFF TORQ recommends 20W50 full synthetic as oil of choice...

Dale

I changed my oil in the K66 at about 300 hours and used 5w-50 weight full synthetic Pennzoil after speaking with a Tufftorq engineer on the phone. Understanding cavitation from my naval research days the lighter oil will reduce the cavitation at the pumping level where the energy is input to the fluid, then the fluid puts the energy to the hydraulic motor for mechanical motion to propel tractor. This will keep erosion of the metal parts to a minimal. If you are in a warmer climate the Tufftorq engineer stated that he uses M1 15w-50 as atop off if doing repairs in the field. 20w-50 maybe in tropical climates, but to me that is a heavy oil for these small pumps to push. I always run WOT to reduce the load on the charge pump as well as the pressure pump for these small hydraulic pumps. The pumpguy I'm sure knows more about this than I.

 

[buckeyefarmer]

For you K46 owners, TUFF TORQ has a complete line of rebuild parts... Have a 2004, JD L120 and after about 400 hours I was having problems, for about $400 you can do a complete rebuild of K46 transaxle.... TT also recommends 20W50 full synthetic for oil.... Funny part is for about $700 I could have bought a NEW one...

Tuff Torq - Integrated Hydrostatic Transaxle Authority

Parts and service..

Tuff Torq Parts

My K46 is $1000 new. And here is their oil. No mention of the weight on the jug.

 

[IH3444]

My K66 stated it came with 5w-50 full synthetic oil, so I kept it the same.

 

[daugen]

I read that my JD X750 comes with a TuffTorque 90 in it, but no such number here:
K92 - Tuff Torq Corporation
has 26 rear tires and I was studying the maximum tire width per model.
Torque load ratings on axles don't seem very high...405 and 650 foot pounds for their two biggest models.
As low as 150 foot pounds on smallest model. Not going to pull much with that...

 

[buickanddeere]

For you K46 owners, TUFF TORQ has a complete line of rebuild parts... Have a 2004, JD L120 and after about 400 hours I was having problems, for about $400 you can do a complete rebuild of K46 transaxle.... TT also recommends 20W50 full synthetic for oil.... Funny part is for about $700 I could have bought a NEW one...

Tuff Torq - Integrated Hydrostatic Transaxle Authority

Parts and service..

Tuff Torq Parts

Are those K46 replacement parts an upgrade with superior materials , improved manufacturing process and a more robust/reliable design ?

 

[IH3444]

My John Deere X750 has the Tufftorq K92 also. John Deere manual states to use the John Deere brand low viscosity fluid, so I do.

 

[daugen]

I always run WOT to reduce the load on the charge pump as well as the pressure pump for these small hydraulic pumps.

assuming pump pressure is linear with rpm, if one is only consuming half of the horsepower produced in normal operation, why
burn more fuel than you have to in order to accomplish the same task? I'm very open to learning here....

btw, I've stopped running my JD, Kubota and MF hydros at idle in puttering around the barn, where I have to go really slow due to limited
clearances between barn and woods and storage sheds. Particularly with a FEL out front and big mower in the back.
I can't imagine running my garden tractor at WOT
for that. Since I use diesels, I like to run at the torque peak plus a little, you listen to hear if it's loaded down, not at rpm peak.
And I understand that WOT really isn't for the engine, there's always another 2-400 rpm in there technically.
I mow roadsides at 460-480 rpm pto operation and I get beautiful results and the Kubota engine sits right at its normal four bars temp.
Everything just sounds right too...but that of course is in the ear of the listener, right?

Could low rpm operation under load be a cause of repair unhappiness for these non commercial hydrostatic transmissions?

While i won't run them at idle, I also won't run them at WOT. Not unless I need to, six foot weeds bushhogging, something I rarely do.
And for pulling a cart of mulch from one spot in my yard to another, do I need WOT?

With a MF/Iseki, Kubota and JD hydrostatic transmissions to maintain, I'm very interested in knowing if I'm operating something improperly.


I always thought you tried to pair output to need, and not waste horsepower or fuel.
But clearly I'm missing something, and maybe low rpm operation of these hydros in mower operation
is screwing them up. BuckeyeFarmer broke an axle in one but I don't think low engine rpm leading to inadequate pump pressure
would break an axle. Could it?

Just hit 500 hours on my JD X750. I'm going to JD dealer, where I haven't been in years, and pick up
their approved fluid unless someone can recommend something with better performance and reliability, out of warranty now.
Maybe I should pick up a tube of that green grease too. Now if machinery could talk...

 

[Tractorable]

I run WOT on my JD X590 when I’m mowing or pulling a heavy dump cart. I do it to keep the blade tip speed up for a good cut and also to provide good flow to the hydraulic pump in the HST. If I’m just puttering from the garage to the barn I’ll use half throttle or so. I only idle if I have to hop off the machine for some reason.

 

[fitterski]

Could low rpm operation under load be a cause of repair unhappiness for these non commercial hydrostatic transmissions?

I have heard that question before but in my case, at least with this mower, it's always been full throttle all the time if only to get the work done in 4 hours or less. I don't like this but am constrained to do it both as a matter of procedure and necessity. On my Cat-426 it's the other way around, its hyd. p]ump gives full pressure at idle and since I'm in no particular rush I do almost all my backhoe work with it just a hair above idle.

 

[fitterski]

I have heard that question before but in my case, at least with this mower, it's always been full throttle all the time if only to get the work done in 4 hours or less. I don't like this but am constrained to do it both as a matter of procedure and necessity. On my Cat-426 it's the other way around, its hyd. p]ump gives full pressure at idle and since I'm in no particular rush I do almost all my backhoe work with it just a hair above idle.

what is "WOT"?

 

[fitterski]

The hydrostatic tranny on my 2009 cub-cadet with only 300 hours is kaput.

I have completely given up on looking for mowers of this size with a manual transmission, there aren't any. BTW the dealer is in communication with Hydro-Gear, they wanted to know the quantity and condition of the oil and were told that it was full (as in never needed refill) and clear. I expect to hear from them this week. Transaxle models sold by surplus-center come with no 'fit' data so are sidelined for now. Otherwise my research is taking the direction of a 3000lbs class mf-35 type tractor with the required implements. Here's a sample, totally restored, for what this mower has cost me including service in 9 years. The price doesn't include the mower itself but has otherwise lasted 50 years and may well last another 50!

https://www.kijiji.ca/v-autos-autre...re/1303652861?enableSearchNavigationFlag=true

TractorData.com Massey Ferguson 35 tractor information

I almost bought one last week but the vendor's attitude ticked me off to the point that after having driven 400kms I just lowballed him to half the asking price and left when he rejected it. It was all over in two minutes

 

[LD1]

what is "WOT"?

Wide open throttle

 

[JerryK]

Believe it or not... Wide open throttle is also called high idle.... Partially because high idle is where they are designed to run....

 

[buckeyefarmer]

I run WOT on lawnmower, it's recommended.

 

[k0ua]

I run WOT on lawnmower, it's recommended.

Same here. Lawnmower yes. But I sure don't run WOT all the time on the tractor. As Daugen said, running a load of mulch across the yard does not seem logical to me. I run enough RPM not to bog the engine and drive system. I will run a lot more throttle in MED range than low range when puttering around. In MED the hydro is "looking" into a lot more load due to the higher gear ratio of MED range so it is stressed more.