Engine oil recommendation

Chris S.

Member
Can someone please help me out with recommendations on a 'common ground' oil weight for my 51 8n? For the life of me I can't remember what I used last oil change and of course I failed to write it down. Thought now would be the time to ask.

I've searched previous posts in this thread and find that most guys are using an appropriate weight oil for colder climates.

I'm middle ground where I'm at in PA. I'm not too worried about the cold months with starting the tractor. It is restored with a rebuilt engine. The tractor resides in a heated building and rarely even comes out in the winter.

Summer months it gets run through some parades and a yearly tractor ride that lasts approx 2 hours in continuous 4th gear. The upcoming tractor ride is what is prompting this oil change actually.

So to sum it up, what you guys recommend using that, like I said, is just a 'common ground' oil that will work year round? I don't really understand the oil weight numbers.
 
Can someone please help me out with recommendations on a 'common ground' oil weight for my 51 8n? For the life of me I can't remember what I used last oil change and of course I failed to write it down. Thought now would be the time to ask.

I've searched previous posts in this thread and find that most guys are using an appropriate weight oil for colder climates.

I'm middle ground where I'm at in PA. I'm not too worried about the cold months with starting the tractor. It is restored with a rebuilt engine. The tractor resides in a heated building and rarely even comes out in the winter.

Summer months it gets run through some parades and a yearly tractor ride that lasts approx 2 hours in continuous 4th gear. The upcoming tractor ride is what is prompting this oil change actually.

So to sum it up, what you guys recommend using that, like I said, is just a 'common ground' oil that will work year round? I don't really understand the oil weight numbers.
I use O'Reilly's brand 20W-50 in all but one of my tractors and have been doing so for decades
 
Tractordata viscosity chart only shows up to a 30 weight. I was thinking about using 10w30 but will adjust depending on my engine. Not saying yours wont run best on a 15w40 just depends on the bearing clearance in your engine.
Tractordata's data is dated. Pun intended. They accurately tell you what the original mfr recommendation was, in this case 1951. If an old bobistheoilguy post is correct, multi viscosity oil was not available until 1954, so they could not have specified 10W-30 at that time. API oil specifications have only improved over the years, so there has never been a good reason not to use the latest revision, up until some of the more recent ones where some minor compromise may have been made to work better with modern emission controls. Old tractors have no emission controls to worry about.*

Long story short, if you really want a 'common ground' oil for both the engine and transmission and hydraulics, you can refer to Allison for engine oils approved for "Allison 5000 Series™, 6000 Series™, 8000 Series™ and 9000 Series™ off-highway [transmission] products". I use Shell Rotella T4 15W-40. Since T6 was added to the list since last time I looked, I would use that as well. The other 25 oils on the list are not readily available to me at Menards for short money, or I wouldn't hesitate to use any of them.

More modern obsolete tractors than the 8N with wet clutches do need tractor fluids with the friction modifiers. The Allison approved oils are not for wet clutches or brakes since they do not have any friction additives like an ATF fluid.

These oils can be used in both the engine and transmission, as long as you are comfortable treating an obsolete, light duty, 1950s engine and transmission like a modern heavy duty off road agricultural, commercial or military vehicle.

*My limited knowledge is inadequate to adequately back up my claim that the more recent emission controls are responsible for the split between diesel and Otto oils. I think (don't know for certain) that the heavy duty diesel oils are actually better for an engine that does not suffer from overly sensitive emission hardware. I think it was the sulfur level that was the problem.
 
To make a long story short It really depends on the engine. They also have rotella t6 in many different viscosities.

Unless we all start doing uoa’s on our tractors who knows but I plan to use an oil that is better suited for flat tappet engines like rotella or valvoline vr1.
 
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Thanks for the replies. I decided to roll with the shell Rotella 15w40. Same as I'm running in my MF. It will keep it easier for future oil changes. I also was able to track down some other YT posts where this topic was covered that I hadn't come across originally. And most importantly, I wrote down what I used this time!
 
I'm trying to change the oil in mine but can't get the drain off. The square shape drive is so worn and tapered I can't get a grip with any wrenches. What have yall done for that?
 
I'm trying to change the oil in mine but can't get the drain off. The square shape drive is so worn and tapered I can't get a grip with any wrenches. What have yall done for that?
Is there anyway you could use a large enough pipe wrench to grip onto the outside of the entire plug rather than just the worn peice?
 
I'm trying to change the oil in mine but can't get the drain off. The square shape drive is so worn and tapered I can't get a grip with any wrenches. What have yall done for that?
The common post I see are to put a pipe wrench on the square then a block of wood then a hydraulic jack to press the wood again the wrench. That should keep the wrench from coming off the poorly designed square of the plug.



I use a air chisel and lightly hit the outer rim of the plug they all have broken the bond for me rat now.
 
I'm trying to change the oil in mine but can't get the drain off. The square shape drive is so worn and tapered I can't get a grip with any wrenches. What have yall done for that?
A PO of mine took a grinder to the cover and ground two flats to grip it with a wrench. After removal I replaced with a new one.
 
The common post I see are to put a pipe wrench on the square then a block of wood then a hydraulic jack to press the wood again the wrench. That should keep the wrench from coming off the poorly designed square of the plug.



I use a air chisel and lightly hit the outer rim of the plug they all have broken the bond for me rat now.
I might try the Jack to hold it in place. If/when I get it out, a new one is going back in!
 
I use 15W40 Amsoil synthetic in my Jubilee. Tractor likes it and my oil pressure never goes below 42 psi.
I use the same oil in my 1953, 235 Chev engine and it still maintains 48 psi (factory pressure) since I rebuilt it in 1975. Expensive oil though.
 
A PO of mine took a grinder to the cover and ground two flats to grip it with a wrench. After removal I replaced with a new one.
That's what I ended up doing, and with the addition of a 3' pipe wrench, finally got it out. Replaced with a new one and didn't gorilla tighten it.
 
Can someone please help me out with recommendations on a 'common ground' oil weight for my 51 8n? For the life of me I can't remember what I used last oil change and of course I failed to write it down. Thought now would be the time to ask.

I've searched previous posts in this thread and find that most guys are using an appropriate weight oil for colder climates.

I'm middle ground where I'm at in PA. I'm not too worried about the cold months with starting the tractor. It is restored with a rebuilt engine. The tractor resides in a heated building and rarely even comes out in the winter.

Summer months it gets run through some parades and a yearly tractor ride that lasts approx 2 hours in continuous 4th gear. The upcoming tractor ride is what is prompting this oil change actually.

So to sum it up, what you guys recommend using that, like I said, is just a 'common ground' oil that will work year round? I don't really understand the oil weight numbers.
15-40 in my W9...JD 520......MF 35 ....Ferguson TEA-20.....Case 830 (8 speed)....Case 930 (6 speed)...... three JD "D's....Ford 2-N
 

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