# Ford 420 engine oil



## Donald A. (Feb 24, 2018)

Hello everyone, 

Quick question. What type of engine oil should I use for my old 3 cyl. diesel Ford 420 tractor?

Thank you and God bless.


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## RC Wells (Dec 26, 2008)

Back in the day Ford recommended diesel rated oils in different weights depending on the ambient air temperature. You can still do the same: SAE 5W when running in conditions below 10 degrees Fahrenheit, SAE 10W for 10 to 40 degrees, SAE 20W for temperatures from 32 to 90 degrees and if the temperature is expected to constantly be above 75 degrees, then SAE 30W.

Or purchase a high quality diesel rated multi-viscosity oil like Cenex Superlube TMS, or Delo 400 SDE, or virtually any diesel engine oil from New Holland, John Deere, Case IH, etc.


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## Ultradog (Feb 27, 2005)

Donald A. said:


> Hello everyone,
> 
> Quick question. What type of engine oil should I use for my old 3 cyl. diesel Ford 420 tractor?
> Thank you and God bless.




Oil is one of those topics that can get the fights started.
Lots of opinions on oil.
On other Ford tractor boards you will find most of guys run a 15W40 diesel rated oil like Delo, Rotella or a good generic equivalent.
There is one guy on another board who recently had to overhaul the 201 ci diesel in his 1980 4600 because the water jacket cavitated into a cylinder wall. At nearly 10K hours, when the machine shop checked out the crank the main journals were still within factory specs and the rod journals nearly so. They did grind the rod journals .010 under.
That is a pretty good testimony to both the 15w40 oil and his maintenance habits.
If you live in cold country like some of us I suggest you invest in a block heater rather than thin your oil down.
I have block heaters in both of my 3 cyl diesels and a couple hours plugged in will let my engine start like it is July.
Speaking of cavitation ...
These 3 cyl Ford engines are somewhat notorious for that problem. Untreated coolant will erode the block and you get coolant leaks into cylinder bores. It can be repaired but only by boring and sleeving the engine.
That is why it is important to use a coolant conditioner in the radiator.
There are other brands a guy can buy but I never know which ones. So I always buy the recommended stuff from New Holland. The part # - fw15 is clearly visible in the photo below.


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## dozer966 (Dec 30, 2014)

Most tractor owners I know use Rotella 15-40 full sinthetic. As ultradog recommended a block heater in colder climates is a must. I even went one step further and put a magnetic oil pan heater to ensure oil flow in the engine. Temperature of -20*C are common in northern Ontario


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## Donald A. (Feb 24, 2018)

Thanks for the reply.

I live in deep east Texas so the cold freezing weather you are mentioning never happens here. I looked at an old operators manual and it recommends SAE 30. Is that correct?


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## Ultradog (Feb 27, 2005)

"I looked at an old operators manual and it recommends SAE 30."

Oils have improved a lot in the 30 years since that manual was printed.
I doubt Any ag manufacturer would recommend 30 wt now.
I would use a 15w40 diesel rated oil and not worry about it.


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## PJ161 (Sep 12, 2016)

I use Rotella 15/40 Summer and Winter and have yet to have a problem with it. Not much oil pressure change hot or cold. I don't dispute the use of any oil brand as long as it suites ones needs. Many years ago, I used re-processed oil because it was cheap in some of the old stuff, Capital in 2 gallon cans from Pep Boys. Had no detergent in it, but that old machinery didn't even notice. Did someone say, they were the good old days? Can't prove it by me. PJ


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## bhayden (Jul 29, 2017)

Rotella is good. My personal favorite based just on a long history with it is Delo. I look for what's on sale  Also, unless you are dealing with temperature extremes I'd use a single weight oil. Multi-vis oil gets it's property of thin when cold from plastic bits that change shape with temperature. The base oil is the lowest number (i.e. thinest) oil. That said, I think it's more important, especially with a diesel, that you change the oil often than what brand you pick.


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