8-n oil

There are several 8n sites on the internet. An Operator's Manual is handy! The manual calls out:

Transmission, differential and hydraulic mechanism Use mild E.P. Gear Oil conforming to Ford specifications M-4864-A & B as follows:
At temp above +32 F - B (SAE 90)
At temp below +32 F - A (SAE 80)
 

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No idea where all of these suggestions are coming from, but I would suggest using what Ford specified in the original Operator's Manual. mild EP SAE 80 or 90 Gear Oil.
 

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oldbugger said:
90 wt is not correct, it needs hydraulic oil, TSC or other tractor supply stores can help you out.[/QUOTE

No, no, no! On these tractors the transmission, differential and hydraulic pump are one common unit and share the same oil. The ring and pinion gears need gear oil, not hydraulic oil!
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There is a specific Ford branded oil that is available at Ford Tractor dealerships. I believe it is a trans-hydraulic type of oil. 80/90 is not recommended for winter use in cold climates(Ontario) Just did a trans overhall for a customer last fall. If you cant get the product number pm me
 
Pennzoil had a "Tractor oil" which was like a medium hydraulic oil. We started using this oil for the man lifts which had been on ATF.
Bruce
 
Ford changed there books on the hydraulic oil sometime around the NAA era but they never updated the old 9N or 8N pubs. The rear axle can use mild EP like GL4 due to the yellow metal in there but most still just use GL1 types. The hydraulic oil recommendations were different with the M-4864-A/-D. A lot of folks use the NH-134 or the AW 46 hydro oil now days.
 
rotorwrench said:
Ford changed there books on the hydraulic oil sometime around the NAA era but they never updated the old 9N or 8N pubs. The rear axle can use mild EP like GL4 due to the yellow metal in there but most still just use GL1 types. The hydraulic oil recommendations were different with the M-4864-A/-D. A lot of folks use the NH-134 or the AW 46 hydro oil now days.
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My Dad bought a 1949 8N new and it has never had anything but AW 46 hydro oil for the last 50+ years, with no problems so far. An old tractor mechanic advised us to change from Ford Brand because he said it was less cost and was the same basic oil. It don't do as much work as it did when it was younger, but it can still handle what we ask of it.
 
Of all the quirks my old 850 has, none are related to the type of lubricants and fluids used. Just about any modern hydraulic oil will likely work, even if it has a lower viscosity. The thing would likely work with SAE 30 motor oil in it. I really should state that Ford really didn't update any of the tractor pubs once the last model of the series was obsoleted. I don't own any of the older N series so I don't have those pubs. The hydraulic systems for the 600 and 800 series aren't much different that the old N series but they were improved a little bit. Just having the 172 CID OHV motor is enough and the 5-speed transmission doesn't hurt anything either.
 
I've never seen an 8n manual (and I have most of them) that recommended anything other than what the original operator's manual recommended. There might be other fluids that would work, but I stick with the original Ford recommendation. Now, just like the oil debates that go on, there are modern products that are often far superior to what was available in the 30s and 40s. So, if there is something better, I'm all for it, but so far I use the Ford suggested fluids (and these tractors are at least into the 50s!).
 
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GL-1 buy it at NAPA or Tractor supply, you don't say where you live, I have a new 5 gal can you can have if your close, I sold my 8N last year. Look at my album to see some pics.
 
when I first got my 8n ( it is a 1948 model ) I changed the hyd. oil from what ever was in it to the recommended hyd. oil, I later had problems and took the tractor to an old tractor mechanic, down in Texas, first thing he did was change the oil back to 80-90wt gl1 He said because if the heat down there in Texas the 80-90 works better. I have seen some where that this was recommended, can't remember where though, may have been in my 8n manual, but it is in Texas and I am In Alaska right now, so I can't check. I have not had any problems with the trans, diff, or the hyd. lift since changing it to the 80-90wt .
 
I stand corrected, but I cant imagine an 80\90 working well in the hyd pump in Michigan winter weather, when I am plowing snow
 
The AW46 that a lot of folks use is a lot less viscous than the gear oil. It's somewhere around what would be SAE 15. This is better for winter climates but may cavitate more in summer. SAE 20 or 30 might be better. That would be somewhere around SAE 60 in the gear oil viscosity ranges. SAE 90 gear oil is the same viscosity as SAE 50 motor oil due to the different viscosity ratings.

As long as it lubricates and doesn't have any compressibility, it will work. A lot of the new ISO hydraulic oils look a lot like motor oils. Mobil DTE 26 is ISO 68 and that is near SAE 20. A lot of light aircraft hydraulic systems still use the old MIL-H-5606 red fluid and that stuff is like SAE 10. It has a tendency to build microbes in it and sometimes the paraffin separates and goes to the bottom of the tank if it sets too long so it's not practical. ATF could also be used but I won't get into that subject.
 
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