Oil & Fuel Front axle fluid

[oldpilgrim]

The hydraulic fluid, and the 80-90w gear oil, are basically the same thing. That's why they are interchangeable in that application, depending on certain factors.

Hydraulic fluid is a 30w.

If you don't know what to put in it, pull the drain plug, then you'll know. Gear oil will be near black and smell badly and hydro fluid will be much lighter in color and consistency. I'd argue that hydro is not the same thickness as the gear oil. I've worked alot with both.

BTW, my 3016 manual is pretty clear...hydro fluid.

 

[ray66v]

Hydraulic fluid is a 30w.

If you don't know what to put in it, pull the drain plug, then you'll know. Gear oil will be near black and smell badly and hydro fluid will be much lighter in color and consistency. I'd argue that hydro is not the same thickness as the gear oil. I've worked alot with both.

BTW, my 3016 manual is pretty clear...hydro fluid.

Many people have trouble accepting this. Sorry, it is not opinion, It is fact. Test them for yourself.

80-90w is not dark, and does not have the familiar burnt smell. Those are the heavy gear oils.

You must not have worked with much 80-90W. It is clear, and thin.

Here is a chart that shows what I am talking about:

 

[oldpilgrim]

I've worked with 80-90 and the heavy gear oils in the past, as I've had many Model T's and A's. They all took 600w gear oil but sometime in the 1980's it was decided that the 80-90w was just as good and I've been using that.

Granted I haven't done much work on them in the past 20 years or so, so maybe the 80-90w stuff has changed, but back then it was much thicker and darker than what is called hydraulic tractor fluid (30w) today.

The UTF stuff I just put in my tractor is a clear light yellow color, almost the color of urine and that's not the way I remember the 80-90 stuff I used before...it being very dark and thick...and smelly...not as dark, thick, and smelly as the old 600w but sufficiently so that it's easily recognizable as gear oil.

Perhaps the stuff has changed as I haven't used any 80-90 for a while. My restoring old car days went away as I tore off more and more pages of the calendar.

Your chart does show that the 80-90 stuff starts at the very top of the 30w range and goes up to the 50w range. I would have expected it to be much higher up the scale based on my past experience.

I bow to your knowledge of current oils.

 

[Browneyesvictim]

Ray66v-
Your chart is proving you somewhat differently. Viscosity testing is normally rated in kinematic centistokes (cSt) at either 100'C or 40'C on the left (more common) or Saybolt Viscosities on the right. What you are trying to show (which is correct) is representing SAE engine oils with other ratings(ISO, AGMA, SAE Gear oils,) within the different rating standards at those given temperature ratings. You are right in that ENGINE Oil ratings are not the same as GEAR oil ratings, however, you are ill advised in making the assumption that Tractor Hydraulic Fluid is an SAE ENGINE oil and comparing it to an SAE GEAR oil. Tractor Hydraulic Fluid is not represented in the chart.

So, to be fair lets look at what brand X rates their viscosities are at 40'C and 100' cSt. ... I did a quick internet search and found:
http://www.sinclairoil.com/pdfs/pds/universal_tractor_hydraulic_fluid.pdf
Mobilfluid 424

The specs for Sinclair brand shows 63.53 @ 40'C cSt and 9.76 @100'C cSt. The Mobile 424 shows 55 @ 40'C cSt and 9.3 @100'C cStwhich puts it closer to an AGMA 2 or ISO 68.

Conversely an SAE multiweight gear oil such as specified 80W- 90 is rated higher at 147.7 @ 40’ cSt and 14.7 @ 100’ cSt- closer to an AGMA 4 or ISO150 (needless to say 85W-140 is even higher at 371.1/26.96 @ 40/100’ cSt)

http://www.sinclairoil.com/pdfs/pds/automotive_gear_oils.pdf
https://mobiloil.com/en/gear-lubricants/mobilube-hd-plus

Conclusion: Universal Tractor Fluid is indeed a lighter weight oil than 80W-90. You are right however, in what I think you are trying to convey in that SAE Engine and SAE Gear oils are in fact rated different.

(Ill be happy to enroll you in the professional development courses I teach on just such a nature. :thumbsup

 

[ray66v]

Ray66v-
Your chart is proving you somewhat differently. Viscosity testing is normally rated in kinematic centistokes (cSt) at either 100'C or 40'C on the left (more common) or Saybolt Viscosities on the right. What you are trying to show (which is correct) is representing SAE engine oils with other ratings(ISO, AGMA, SAE Gear oils,) within the different rating standards at those given temperature ratings. You are right in that ENGINE Oil ratings are not the same as GEAR oil ratings, however, you are ill advised in making the assumption that Tractor Hydraulic Fluid is an SAE ENGINE oil and comparing it to an SAE GEAR oil. Tractor Hydraulic Fluid is not represented in the chart.

So, to be fair lets look at what brand X rates their viscosities are at 40'C and 100' cSt. ... I did a quick internet search and found:
http://www.sinclairoil.com/pdfs/pds/universal_tractor_hydraulic_fluid.pdf
Mobilfluid 424

The specs for Sinclair brand shows 63.53 @ 40'C cSt and 9.76 @100'C cSt. The Mobile 424 shows 55 @ 40'C cSt and 9.3 @100'C cStwhich puts it closer to an AGMA 2 or ISO 68.

Conversely an SAE multiweight gear oil such as specified 80W- 90 is rated higher at 147.7 @ 40 cSt and 14.7 @ 100 cSt- closer to an AGMA 4 or ISO150 (needless to say 85W-140 is even higher at 371.1/26.96 @ 40/100 cSt)

http://www.sinclairoil.com/pdfs/pds/automotive_gear_oils.pdf
https://mobiloil.com/en/gear-lubricants/mobilube-hd-plus

Conclusion: Universal Tractor Fluid is indeed a lighter weight oil than 80W-90. You are right however, in what I think you are trying to convey in that SAE Engine and SAE Gear oils are in fact rated different.

(Ill be happy to enroll you in the professional development courses I teach on just such a nature. :thumbsup

As I said, viscosity varies dramatically. If you pick the right two products they will be closer. Compare the same product from different manufacturers, and they can be widely different. That is another thing people don't realize. Two 30w oils can have a fairly different viscosity.

For all intent and purpose, they are similar enough to be considered the same, in most cases.

I said, they are BASICALLY the same, and that is true.

And, as I said, if you do a timed pour test, you will not see significant differences. It's been done, to try and prove this wrong in the past.

Most people's conception of 80-90w is incorrect.

The technical aspects, and splitting of hairs are not important, as to the fact that either is completely interchangeable in this instance, as a front axle lubricant. All I am trying to convey is, the reason why is, they really aren't different.

Some refuse to accept it. I'm fine with that. Only trying to help those who are interested.

 

[Jabonee]

80-90 for the diff. use the hyd fluid for cold weather climates and winter use.

 

[johnsonauto]

Sorry to resurrect an old thread. This has come up again recently, but I'm curious what exactly the MFD fluid is? Is it hydraulic oil or gear oil? I'm looking in my manuals and its obvious there is conflicting information specifying what are very different types and viscosities of oils. I'm talking specifically for the front diff oil (for MAX 25) it refers to "MFD fluid", "Mahindra Universal Tractor Fluid, and also "Mahindra EP gear oil SAE 80W-90". The "EP" in the gear oil tells me there are extreme pressure friction modifiers that the hydraulic oil would not normally have. This may or may not be important with limited slip clutches. Furthermore, 80W-90 is a lot heavier than hydraulic fluid and certainly not 85-140!

Either fluid is acceptable and will work fine for the Max series tractors. We use the Mahindra UTHF in them when servicing them in the shop and have never had a problem. My understanding is years ago they used 80w90 in the front axle, but at some point they found the transmission/hydraulic fluid meets the specs for it as well.

 

[Texas Dawg]

This thread is a prefect example of why this site is so valuable. As a relative newbie to the tractor world things sometimes get confusing. Earlier today "Mahindra Don" posted a video of the basic service for a Max tractor. He mentioned the hydraulic fluid for the transmission and to make sure NOT to put gear oil in there. He went to the MFD and showed what to do there, and mentioned that this is where the gear oil went. That confused me because the owner's manual says to use hydraulic fluid. Lo and behold, a few hours later this thread pops up and clears up the confusion. There is a world of knowledge on here from guys who have been there and done that. Us newbies can learn a lot of valuable lessons here without having to learn the hard (and expensive) way of trial and error. Thank you to all of the old pros who share your knowledge with us rookies.