Re: NAA Hydraulic Fluid

There won't be any contamination of the transmission or differential oil. The NAA has it's own hydraulic sump.

(quoted from post at 14:23:01 11/21/18) There won't be any contamination of the transmission or differential oil. The NAA has it's own hydraulic sump.

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I know how the NAA sumps work and after 50+ years leaks between the sumps is pretty common. That was not an issue with the original gear oils but definitely a concern if using a modern hydraulic oil that is not suitable for use in transmissions and/or final drives. You asked for advice - up to you what you want to do with it.

TOH

That wasn't me that asked. How dare I question you though.

(quoted from post at 12:30:48 11/22/18) That wasn't me that asked. How dare I question you though.

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My apologies for confusing you with the OP. I don't mind being questioned - in fact I enjoy a good debate. So did you simply miss the place in my initial response where I explicitly cited seal leakage as a potential problem or have you changed your mind about the reliability of the 64 year old inter-sump seals in an NAA since you posted this on the Ford forum?

TOH

[b:30bab6a153]Jim L WA
05-11-2018
09:32:25[/b:30bab6a153]

Re: Jubilee questions in reply to Ohio88, 05-10-2018 16:44:07

Hi Ohio88, do you have the I&T FO-19 shop manual? Great info in there. From what I can see from the manual, [color=red:30bab6a153]if your rear end oil is leaking into the hydraulic sump, the front PTO seal is leaking and you will need to split the tractor to fix that.[/color:30bab6a153]

TOH; I may have missed your point where you explicitly cited seal leakage as a potential problem. What caused me to respond was that you recommend an 80 wt. UTF fluid in the hydraulic sump and that made me think that you might have the N tractors mixed up with the NAA. But you didn't. Now here is a question for you, would that 80 wt. UYF work well in low temperatures like 20 degrees or colder? I don't know if my old vane type pump could handle that.

(quoted from post at 14:53:41 11/23/18) TOH; I may have missed your point where you explicitly cited seal leakage as a potential problem. What caused me to respond was that you recommend an 80 wt. UTF fluid in the hydraulic sump and that made me think that you might have the N tractors mixed up with the NAA. But you didn't. Now here is a question for you, would that 80 wt. UYF work well in low temperatures like 20 degrees or colder? I don't know if my old vane type pump could handle that.

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Good question and I am going to give a lengthy answer so please bear with me. If you want to skip the wonky analysis simply read the paragraph preceding my sig.

The original recommendation in the NAA owners manual was for M4864A - Mild EP SAE 80 tractor hydraulic oil - AKA gear oil. At that point in time gear oils had a viscosity index of roughly 90-100 and in cold (sub-freezing) weather that oil got so thick it was hard for the vane pump to pull it from the sump. Consequently the owner's manual recommended M4864C (SAE viscosity grade unknown) when ambient temperatures fell below 20F. I think it is safe to assume it was a lower viscosity that the A type oil.

A modern UTF is also an SAE 80 gear oil but it has a much higher viscosity index - upwards of 135 - which means it does not thicken nearly as rapidly and will remain pumpable at temperatures well below the original A type oil could tolerate. But that leaves a gray area where we can't readily compare the UTF to M4864C.

So now lets turn our attention to a modern hydraulic oil like you are using. Hydraulic oil viscosity is graded at 40C per the ISO standard as opposed to gear oils which are graded at 100C per the SAE standard. For use in mobile equipment the three most common grades are ISO VG's 32, 48, ant 68. Unlike the SAE grading system, in the ISO standard the grade numbers are the actual measured viscosity of the oil with an allowance of +/- 10% of the nominal grade. So we can easily calculate that an ISO VG 48 hydraulic oil has a measured viscosity in the range of 43.2 to 52.8 cSt @ 40C. We also know that most conventional hydraulic oils are formulated with Group II base oils and no VI improvers and as a consequence have a viscosity index of around 100 - much like the 1952 era gear oils.

With that as a baseline let's turn our attention back to the UTF products. Looking at the product data sheets we find they have a measured kinematic viscosity in the vicinity of 50-55 cSt @ 40C. It varies somewhat by brand but it's pretty consistently in that range so that puts UTF at or just barely over the upper bound of an ISO VG 48 hydraulic oil. UTF's also have a viscosity index of 135+ as opposed to 100 which means they are going to thicken a lot slower than a conventional hydraulic oil. I can run the calculations if you want but I will go out on a limb and speculate that UTF outperforms even the thinnest of conventional ISO VG 48 hydraulic oils at temperatures below freezing.

So unless you are using an ISO VG 32 hydraulic oil I am confident a UTF will pump as easily as if not better than the R&O oil you are currently using. For all practical purposes it is an ISO VG 48 hydraulic oil and will thicken less when cold and thin less when hot than a conventional ISO 48 hydraulic oil..

TOH

[b:9048a8f388]ADDENDUM[/b:9048a8f388] - Both UTF and AW hydraulic oils have a mild EP anti-wear additive package that was present in the original Ford hydraulic/gear oils but is missing from a modern R&O hydraulic oil.

Isn't the sump open from trans to final drive on a jubilee as the 8n ? I was thinking that was the difference between the jub. & the naa.

(quoted from post at 15:18:50 11/24/18) Isn't the sump open from trans to final drive on a jubilee as the 8n ? I was thinking that was the difference between the jub. & the naa.

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No - the NAA was introduced in 1953 and that model year was designated as the Golden Jubilee. It was the same as the NAA tractor manufactured in 1954 with the exception of special Golden Jubilee nose badging. Both model years of the NAA and the follow on Hundred series tractors had a separate hydraulic sump.

TOH

Thank you for clearing that up.I have yet to take apart the back
end of my Jub. and i am more familiar the 8-n.I currently have
mineral gear oil in my 8-n.but yes it is stiff in cold
weather.In my jubilee should I run The mineral gear oil in the
trans and Traveler UTF in the rear drive that also doubles as
the hyd. sump?Or would the UTF be acceptable in both? Thank you
for your input.....

(quoted from post at 16:32:30 11/24/18) Thank you for clearing that up.I have yet to take apart the back
end of my Jub. and i am more familiar the 8-n.I currently have
mineral gear oil in my 8-n.but yes it is stiff in cold
weather.In my jubilee should I run The mineral gear oil in the
trans and Traveler UTF in the rear drive that also doubles as
the hyd. sump?Or would the UTF be acceptable in both? Thank you
for your input.....

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In this day and age I see no need for multiple fluids. UTF is a very good approximation to the original NAA specifications for both summer and winter use. If I owned an NAA or Hundred series I would use UTF in all three sumps. If you browse the Ford forum I think you will find that to be the general consensus.

TOH

TOH, thanks for the lesson on oils. With the possibility of the seals starting to leak at any time, if they already aren't, I think I will change my oils out to UTF.

That's what I'll do. After posting the last
time I went out to my shop & got my manuals
and found the info I needed. Jub.has been
apart for a few yrs.engine clutch paint
ect.getting ready to put all the fluids
back in it and start it for the first time.
Thanks again for your input.....

(quoted from post at 17:51:32 11/24/18) TOH, thanks for the lesson on oils. With the possibility of the seals starting to leak at any time, if they already aren't, I think I will change my oils out to UTF.

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You are welcome. Looking back at my dissertation I see I got a little out over my skis. I hate it when that happens

There is no ISO VG 48 - it should be ISO VG 46 and after looking at some more data sheets the typical viscosity for premium UTF is more like 55-60 cSt @ 40C so the math should be adjusted accordingly. That puts UTF viscosity about midway between ISO VG 46 and ISO VG 68.

TOH

(quoted from post at 17:51:32 11/24/18) TOH, thanks for the lesson on oils. With the possibility of the seals starting to leak at any time, if they already aren't, I think I will change my oils out to UTF.

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I hate speculating when engineering data are readily available so I plotted the viscosity curves of the common grades of hydraulic oil alongside typical UTF. The input data are taken from the data sheets for Warren AW hydraulic oils and CNH Ambra Multi-G 134. Here is the graph - UTF is just ever so slightly heavier than AW 46 down to 23F (-5) where the curves cross. FWIW, according to the OEM the Multi-G UTF is designed to function down to -5F (-20C).

TOH

Nice tool! I'm going to use it to compare UTF and SAE 90 mineral oil (the two that are talked about all the time.

According to Valvoline, their SAE 90 GL-1 straight mineral gear oil has the following properties:
==========================
API Service GL-1 SAE 90
Viscosity @ 100° C, cSt 17.0
Viscosity @ 40° C, cSt 189.7
==========================
A graph showing these characteristics is quite enlightening as to low temperature performance. No wonder the hydraulics are sluggish in the winter with mineral oil!



The tool.

(quoted from post at 13:07:22 11/25/18) Nice tool! I'm going to use it to compare UTF and SAE 90 mineral oil (the two that are talked about all the time.

According to Valvoline, their SAE 90 GL-1 straight mineral gear oil has the following properties:
==========================
API Service GL-1 SAE 90
Viscosity @ 100° C, cSt 17.0
Viscosity @ 40° C, cSt 189.7
==========================
A graph showing these characteristics is quite enlightening as to low temperature performance. No wonder the hydraulics are sluggish in the winter with mineral oil!

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It is very handy as are the other calculators on the Widman site. I have used it to post lots of comparisons here over the years including the one you just posted ;-) One of the most misunderstood technical issues motor heads run into is oil viscosity and most especially how the SAE viscosity grading system works. Seeing actual viscosity curves busts a lot of myths. For example most people are amazed when they see a graph of the much beloved multi-grade SAE 20W50 alongside a mono-grade SAE 30. SAE 20W50 is a horrible cold weather oil - considerably worse than a mono-grade SAE 30.

TOH