Buying Advice Done with hydrostatics

[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.