changing transmission fluid ford 8n

RWD · Dec 18, 2011

I want to change the transmission fluid in my 1948 Ford 8n and the bools leave me a bit confused. Can anyone walk me thru it and let me know if as the book states, does it really take 20 qts?
Tanks

OK8N · Dec 18, 2011

Actually, 18 to 19 quarts is fine. And the fluid is also used by the hydraulic system. I use 80-90 wt. mineral oil in mine.

HCooke · Dec 18, 2011

Yes, there are 5 gal in there. You will need a big bucket! Three drain holes. The rear end the hydraulics and the trans are all connected. Start with the pipe plug in the rear end and work your way forward with the draining. Uses either 90 wt GL1 or universal hydraulic fluid that meets Ford 134d specs.

Tom N MS · Dec 18, 2011

Takes somewhere between 16 and 18 quarts..remove bottom bolt from inspection cover where dipstick is located--fill it till it runs out of this hole..won"t show quite full on the dfipstick but don"t worry about that....whwn draining it remove the rear most plug--it is the smallest hole so you will be able to aim it in a bucket better and get most of it drained from there(3 gal or so)..then remove the next plug which is in the pump, then remove the next plug which is basically in line with the shift lever..let it drain till U know it has all drained out--overnight is good but not necessary..replace all three plugs and fill through the big plug hole by the shift lever.....Hope this helps Depends on where you are but original oil was GL-1 90 wt mineral oil 134 is thinner so if U are in a cold climate it will warm up and the hydraulics will work smooth faster but in hot climate the 134 is more likely to leak if you have leaks anywhere....

TheOldHokie · Dec 18, 2011

(quoted from post at 16:03:13 12/18/11) Actually, 18 to 19 quarts is fine. And the fluid is also used by the hydraulic system. I use 80-90 wt. mineral oil in mine.

Folks are really hung up on this "mineral oil" thing.

[b:2a66dbf066]Question:[/b:2a66dbf066] What modern automotive lubricating oils are not "mineral oil"?
[b:2a66dbf066]Answer:[/b:2a66dbf066] Only the very expensive PAO based synthetics. [u:2a66dbf066][b:2a66dbf066]ALL[/b:2a66dbf066][/u:2a66dbf066] conventional lubricating oils refined from crude oil pumped out of the ground are "mineral oil".

So any conventionally refined UTF is in fact "SAE 80 mineral oil". And since the API allows highly refined Group III mineral oils to be labeled as synthetic even some "synthetic" UTF's made from Group III base oils are actually "mineral oil". I suspect the reason Ford specifically said "mineral" oil in 1939 was to warn farmers against dumping things like whale oil, corn oil, or liquid lard in the sump. Nahhh - they were all smarter than that right?

TOH

PS> And IMO absolutely nothing wrong with a true syntehtic either other than the high cost.

OK8N · Dec 19, 2011

Thanks for the clarification, although I don't think I have a hang up about the term "mineral oil" - just being lazy. Folks around here differentiate 90wt transmission mineral oil from UTF and gear lube. When I ask for mineral oil for my tractor transmission, this is what I get:

TOH said: - So any conventionally refined UTF is in fact "SAE 80 mineral oil". - 

I was not aware of this. My understanding was that many UTFs were lighters oils, as reports of increased UTF oil leakage by some "N" owners who have used both UTF and GL1 "mineral oil". I've also read that oil which conforms to specification M2C134D (Ford-New Holland spec for "N" tractors) is equivalent to an SAE rating of between 40-50. Obviously I'm no tribologist.

TheOldHokie · Dec 19, 2011

(quoted from post at 13:51:55 12/19/11) Thanks for the clarification, although I don't think I have a hang up about the term "mineral oil" - just being lazy. Folks around here differentiate 90wt transmission mineral oil from UTF and gear lube. When I ask for mineral oil for my tractor transmission, this is what I get:

<img src="http://okiedoke.com/8n/90wtoil.jpg">

TOH said: - So any conventionally refined UTF is in fact "SAE 80 mineral oil". - 

I was not aware of this. My understanding was that many UTFs were lighters oils, as reports of increased UTF oil leakage by some "N" owners who have used both UTF and GL1 "mineral oil". I've also read that oil which conforms to specification M2C134D (Ford-New Holland spec for "N" tractors) is equivalent to an SAE rating of between 40-50. Obviously I'm no tribologist.

First off I wasn't picking on you in particular - your post just happened to be the last of many that finally elicited my comment. I'm not a tribologist either but you don't have to be one to understand how the [b:6899c2b577]grading[/b:6899c2b577] system works. And it does not work like the vast, vast majority of people think.

The SAE viscosity numbers are viscosity [b:6899c2b577]grade labels[/b:6899c2b577] not units of measure - sort of like light, medium, and heavy. Sometimes I think the SAE would have been better off if they had actually gone that route instead of using numbers. And to make matters worse there are different grading standards for gear oil (SAE J306) and motor oil (SAE J300). The J300 motor oil grades are designated SAE 20, 30, 40, 50, and 60. The J306 gear oil grades are designated SAE 80, 85, 90, 110. 140, 190, and 240. And while the motor oil and gear oil grade [u:6899c2b577][b:6899c2b577]numbers[/b:6899c2b577][/u:6899c2b577] do no overlap the [u:6899c2b577][b:6899c2b577]actual viscosities[/b:6899c2b577][/u:6899c2b577] associated with those numbered grades do. Here is a subset of the full specifications - if you want way more detail try my little monograph on the subject: [u:6899c2b577]J300 Explained[/u:6899c2b577]

SAE J300 motor oil viscosity grades:

SAE 30 - 9.3-12.4 cSt @100C
SAE 40 - 12.5-16.2 cSt@100C
SAE 50 - 16.3 - 21.8 cSt @100C

SAE J306 gear oil viscosity grades:

SAE 80 - 7.0 - 10.9 cSt @100C
SAE 85 - 11.0 - 13.4 cSt @100C
SAE 90 - 13.5 - 18.4 cSt @100C

Which brings us to UTF type lubricants which are technically not a motor oil or a gear oil and as such are not tested to and don't qualify for an official API/SAE "starburst" viscosity label. But when folks - including the OEM - decide to put an SAE grade number on a UTF product for "informative" purposes they have to choose: motor oil or gear oil grade? Case in point - CNH Ambra 134G universal fluid (e.g. M2C-134D). I emailed the OEM that makes that product for CNH and the specified viscosity is 9.4 cSt @ 100C. That makes it either SAE 30 using the J300 motor oil specification or SAE 80 using the J306 gear oil specification. Two differnt viscosity grade labels but in fact the same viscosity - take your pick either one is "correct". Hence a lot of confusion. I've looked at a lot of UTF product specifications and they fall somewhere in the 9.0 cSt to 11.5 cSt range. So if you want to scare someone off of UTF tell them its SAE 30 oil. If you want to make them comfortable with it tell them its SAE 80 or 85 oil. If you want to be coldly scientific and accurate about it tell them that depending on the brand and formulation it has a viscosity somewhere in the range 9.0 - 11.5 cSt @100C. And either way it's mineral oil ;-)

TOH

martyh · Jun 14, 2016

(quoted from post at 15:20:21 12/19/11)

(quoted from post at 13:51:55 12/19/11) Thanks for the clarification, although I don't think I have a hang up about the term "mineral oil" - just being lazy. Folks around here differentiate 90wt transmission mineral oil from UTF and gear lube. When I ask for mineral oil for my tractor transmission, this is what I get:

<img src="http://okiedoke.com/8n/90wtoil.jpg">

TOH said: - So any conventionally refined UTF is in fact "SAE 80 mineral oil". - 

I was not aware of this. My understanding was that many UTFs were lighters oils, as reports of increased UTF oil leakage by some "N" owners who have used both UTF and GL1 "mineral oil". I've also read that oil which conforms to specification M2C134D (Ford-New Holland spec for "N" tractors) is equivalent to an SAE rating of between 40-50. Obviously I'm no tribologist.

Click to expand...

First off I wasn't picking on you in particular - your post just happened to be the last of many that finally elicited my comment. I'm not a tribologist either but you don't have to be one to understand how the [b:75f4b5a087]grading[/b:75f4b5a087] system works. And it does not work like the vast, vast majority of people think.

The SAE viscosity numbers are viscosity [b:75f4b5a087]grade labels[/b:75f4b5a087] not units of measure - sort of like light, medium, and heavy. Sometimes I think the SAE would have been better off if they had actually gone that route instead of using numbers. And to make matters worse there are different grading standards for gear oil (SAE J306) and motor oil (SAE J300). The J300 motor oil grades are designated SAE 20, 30, 40, 50, and 60. The J306 gear oil grades are designated SAE 80, 85, 90, 110. 140, 190, and 240. And while the motor oil and gear oil grade [u:75f4b5a087][b:75f4b5a087]numbers[/b:75f4b5a087][/u:75f4b5a087] do no overlap the [u:75f4b5a087][b:75f4b5a087]actual viscosities[/b:75f4b5a087][/u:75f4b5a087] associated with those numbered grades do. Here is a subset of the full specifications - if you want way more detail try my little monograph on the subject: [u:75f4b5a087]J300 Explained[/u:75f4b5a087]

SAE J300 motor oil viscosity grades:

SAE 30 - 9.3-12.4 cSt @100C
SAE 40 - 12.5-16.2 cSt@100C
SAE 50 - 16.3 - 21.8 cSt @100C

SAE J306 gear oil viscosity grades:

SAE 80 - 7.0 - 10.9 cSt @100C
SAE 85 - 11.0 - 13.4 cSt @100C
SAE 90 - 13.5 - 18.4 cSt @100C

Which brings us to UTF type lubricants which are technically not a motor oil or a gear oil and as such are not tested to and don't qualify for an official API/SAE "starburst" viscosity label. But when folks - including the OEM - decide to put an SAE grade number on a UTF product for "informative" purposes they have to choose: motor oil or gear oil grade? Case in point - CNH Ambra 134G universal fluid (e.g. M2C-134D). I emailed the OEM that makes that product for CNH and the specified viscosity is 9.4 cSt @ 100C. That makes it either SAE 30 using the J300 motor oil specification or SAE 80 using the J306 gear oil specification. Two differnt viscosity grade labels but in fact the same viscosity - take your pick either one is "correct". Hence a lot of confusion. I've looked at a lot of UTF product specifications and they fall somewhere in the 9.0 cSt to 11.5 cSt range. So if you want to scare someone off of UTF tell them its SAE 30 oil. If you want to make them comfortable with it tell them its SAE 80 or 85 oil. If you want to be coldly scientific and accurate about it tell them that depending on the brand and formulation it has a viscosity somewhere in the range 9.0 - 11.5 cSt @100C. And either way it's mineral oil ;-)

TOH

I know this is an old post but it is exactly what I needed. This clears up every question I had about choosing the correct fluid for my new to me 1940 9N. I too was confused about labels indentifying 90 weight gear oil versus 30 weight UTF.

I'll be using the Rotella UTF in my 9N.

TheOldHokie · Jun 14, 2016

(quoted from post at 09:22:28 06/14/16)

(quoted from post at 15:20:21 12/19/11)

(quoted from post at 13:51:55 12/19/11) Thanks for the clarification, although I don't think I have a hang up about the term "mineral oil" - just being lazy. Folks around here differentiate 90wt transmission mineral oil from UTF and gear lube. When I ask for mineral oil for my tractor transmission, this is what I get:

<img src="http://okiedoke.com/8n/90wtoil.jpg">

TOH said: - So any conventionally refined UTF is in fact "SAE 80 mineral oil". - 

I was not aware of this. My understanding was that many UTFs were lighters oils, as reports of increased UTF oil leakage by some "N" owners who have used both UTF and GL1 "mineral oil". I've also read that oil which conforms to specification M2C134D (Ford-New Holland spec for "N" tractors) is equivalent to an SAE rating of between 40-50. Obviously I'm no tribologist.

Click to expand...

First off I wasn't picking on you in particular - your post just happened to be the last of many that finally elicited my comment. I'm not a tribologist either but you don't have to be one to understand how the [b:9badd62c49]grading[/b:9badd62c49] system works. And it does not work like the vast, vast majority of people think.

The SAE viscosity numbers are viscosity [b:9badd62c49]grade labels[/b:9badd62c49] not units of measure - sort of like light, medium, and heavy. Sometimes I think the SAE would have been better off if they had actually gone that route instead of using numbers. And to make matters worse there are different grading standards for gear oil (SAE J306) and motor oil (SAE J300). The J300 motor oil grades are designated SAE 20, 30, 40, 50, and 60. The J306 gear oil grades are designated SAE 80, 85, 90, 110. 140, 190, and 240. And while the motor oil and gear oil grade [u:9badd62c49][b:9badd62c49]numbers[/b:9badd62c49][/u:9badd62c49] do no overlap the [u:9badd62c49][b:9badd62c49]actual viscosities[/b:9badd62c49][/u:9badd62c49] associated with those numbered grades do. Here is a subset of the full specifications - if you want way more detail try my little monograph on the subject: [u:9badd62c49]J300 Explained[/u:9badd62c49]

SAE J300 motor oil viscosity grades:

SAE 30 - 9.3-12.4 cSt @100C
SAE 40 - 12.5-16.2 cSt@100C
SAE 50 - 16.3 - 21.8 cSt @100C

SAE J306 gear oil viscosity grades:

SAE 80 - 7.0 - 10.9 cSt @100C
SAE 85 - 11.0 - 13.4 cSt @100C
SAE 90 - 13.5 - 18.4 cSt @100C

Which brings us to UTF type lubricants which are technically not a motor oil or a gear oil and as such are not tested to and don't qualify for an official API/SAE "starburst" viscosity label. But when folks - including the OEM - decide to put an SAE grade number on a UTF product for "informative" purposes they have to choose: motor oil or gear oil grade? Case in point - CNH Ambra 134G universal fluid (e.g. M2C-134D). I emailed the OEM that makes that product for CNH and the specified viscosity is 9.4 cSt @ 100C. That makes it either SAE 30 using the J300 motor oil specification or SAE 80 using the J306 gear oil specification. Two differnt viscosity grade labels but in fact the same viscosity - take your pick either one is "correct". Hence a lot of confusion. I've looked at a lot of UTF product specifications and they fall somewhere in the 9.0 cSt to 11.5 cSt range. So if you want to scare someone off of UTF tell them its SAE 30 oil. If you want to make them comfortable with it tell them its SAE 80 or 85 oil. If you want to be coldly scientific and accurate about it tell them that depending on the brand and formulation it has a viscosity somewhere in the range 9.0 - 11.5 cSt @100C. And either way it's mineral oil ;-)

TOH

Click to expand...

I know this is an old post but it is exactly what I needed. This clears up every question I had about choosing the correct fluid for my new to me 1940 9N. I too was confused about labels indentifying 90 weight gear oil versus 30 weight UTF.

I'll be using the Rotella UTF in my 9N.

I had completely forgotten that post and I am glad that makes sense to you. Your reading comprehension score is higher than most ;-)

TOH

PS> There is more to the story than viscosity.....

changing transmission fluid ford 8n

RWD

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