Newer Tractors Use 75 Weight Hydraulic Oil???

[lastcowboy32]

We have a three year old tractor.

I am specifically withholding the brand name, because I want to know if this is common among brands.

When I went to change the universal transmission/hydraulic fluid, I went to a dealer, they sold me a 20 weight universal transmission/hydraulic fluid.

I actually had the manual with me and showed them the page where it said that the tractor needed 75weight fluid.

I was told that the manual was wrong.

I questioned that... then they asked... Did you drain the tractor? I did. And they asked, What did it flow like?

I have to say, the oil flowed out of the tractor like motor oil, not 75W gear oil. Then I got thinking about how that same oil runs all of the hydraulics and has to get pumped around the tractor...

How the heck would you pump 75W gear oil out to a loader cylinder?

He also asked, What did it smell like? Like gear oil? My answer there is no.

What he said is that the manual confused the gear oil for the four wheel drive front end... which SHOULD be 75W gear oil... with the universal transmission/hydraulic fluid in the back end.

Does anybody have a brand of tractor that specifies 75W oil for the universal transmission/hydraulic oil in the back end???

My tractor, specifically has gears, so it's not fully hydrostatic, but it has wet brakes, a power reverser, a hydraulic clutch and a hydraulic PTO clutch. It also has two full remotes and a loader, which need to run from this same sump.

 

[Jim.ME]

(quoted from post at 10:33:35 06/30/22) We have a three year old tractor.

I am specifically withholding the brand name, because I want to know if this is common among brands.

When I went to change the universal transmission/hydraulic fluid, I went to a dealer, they sold me a 20 weight universal transmission/hydraulic fluid.

I actually had the manual with me and showed them the page where it said that the tractor needed 75weight fluid.

I was told that the manual was wrong.

I questioned that... then they asked... Did you drain the tractor? I did. And they asked, What did it flow like?

I have to say, the oil flowed out of the tractor like motor oil, not 75W gear oil. Then I got thinking about how that same oil runs all of the hydraulics and has to get pumped around the tractor...

How the heck would you pump 75W gear oil out to a loader cylinder?

He also asked, What did it smell like? Like gear oil? My answer there is no.

What he said is that the manual confused the gear oil for the four wheel drive front end... which SHOULD be 75W gear oil... with the universal transmission/hydraulic fluid in the back end.

Does anybody have a brand of tractor that specifies 75W oil for the universal transmission/hydraulic oil in the back end???

My tractor, specifically has gears, so it's not fully hydrostatic, but it has wet brakes, a power reverser, a hydraulic clutch and a hydraulic PTO clutch. It also has two full remotes and a loader, which need to run from this same sump.

Just my opinion here: Withholding exactly what you are working on is only going to lead to a guessing game. How would anyone know if they have the same tractor as yours? They might have a different addition of the manual they could check. And there might be a dealer or mechanic for the brand you have, on this site, who would weigh in.

 

[lastcowboy32]

I understand.

I want to leave the brand out of it, to see if people just respond with something like...

"Yes, all modern power shift transmissions are now using 75W universal fluid in their back ends..."

I will share the brand. I just want to know if there is something obvious and common here... one way or the other... as in 75W is way too thick for universal fluid?

I'm also wondering if it's the specs... for instance, before I changed the fluid, I was buying a universal fluid made by Lucas Oil in one gallon containers for topping off, due to some leaks that I had in the loader tilt cylinder seals.

If you look at the technical data sheet for it... it gives two viscosities.

60 at 40 degrees C... (which would be about 104 degrees F)

9 at 100 degrees C... (which would be about 212 degrees F)

Is my manual specifying viscosity of 75 at some really low temperature? While the fluid that I was sold is specifying it at an operating temperature?

Here is the data sheet for what I used for topping off.

https://lucasoil.com/pdf/TDS_Universal-Hydraulic-Fluid.pdf

 

[lastcowboy32]

Well... now I'm going to mention the brand, Mahindra. Because it's made overseas.

Because, I just found a table of viscosity vs temperature... and, apparently, there is an ISO (International Standards Organization) viscosity standard and an SAE (Society of Automotive Engineers) viscosity standard.

An ISO viscosity of 68 is specified at 40C... and is equivalent to SAE viscosity of 20, specified by minimum and maximum viscosities at 100C.

Yes, I know the attached table is for engine oil.

Now... I go to my manual to see if it specifies viscosity by ISO or SAE... or if it even says.

 

[Jim.ME]

Try reading this article from Amsoil and check out the chart.

https://blog.amsoil.com/gear-oil-vs-engine-oil/

 

[lastcowboy32]

(quoted from post at 10:03:47 06/30/22)
Try reading this article from Amsoil and check out the chart.

https://blog.amsoil.com/gear-oil-vs-engine-oil/

Good article.

My manual says SAE, by the way.

Now, I wonder if these "UTTO" (which I would guess are "Universal Tractor Transmission Oils") are standard in which viscosity spec they use. Do they specify the viscosity like a gear oil, but it flows like hydraulic fluid? Or do they specify the viscosity like a hydraulic fluid, but it has the additives of gear oil? Does every manufacturer do it the same way?

Because, if I read this chart correctly, a fluid using the gear oil viscosity rating, and having a rating of 20, would flow like rubbing alchohol.

 

[lastcowboy32]

Either way.

The manual is correct.

What is wonky, it would seem, is how different brands specify the weight of their UTTO fluids.

 

[lastcowboy32]

And my understanding of gear oil weight. I assumed 75W gear oil would be thicker than motor oil that I've been around, which is usually between 5W and 40W (although, my little Mitsubishi car uses 0W-20... talk about runny oil). My perception was wrong!

 

[lastcowboy32]

As is my habit.

I may be beating a dead horse, but I was able to find the product data sheet for the oil that the dealer sold me.

Apparently, its viscosity is 68.5 at 40C (which would be 104F)... which is the number to use to compare to the spec of 75 in the manual.

However, the data sheet also lists an "SAE Viscosity Grade" of 20W.

The pails only show the 20W rating.

To be honest, I'm still a little anxious. I wish they would have picked something from the approved list in the manual.

I had the fluid drained, I had the tractor parked in the middle of the driveway with a bunch of cardboard boxes underneath to contain any drips from the procedure, and we had seven loads of hay drying in the field. I didn't want to argue. I needed that machine buttoned back up. They said... "This is what we are loading these tractors with during service..." I have to assume that they are working in good faith.

But, in the end, it's my fault for being rushed. Would have been better to have that discussion before servicing the tractor.

There is another whole post here about using sight glasses to measure oil level in the back end of the tractor. I find it to be a PITA for my 50 year old eyes, especially depending on the angle of the sun and other factors.

http://www.warrenoil.com/MSDS-Spec/PDS/Gold%20Band/PDS%20-%20Gold%20Band%20Agricultural%20Hydraulic%20Fluid.pdf