Gear Oil Upgrade For Towing

[Hootbro]

I wonder if ECGS did their own testing.

Currie found the same thing. Cooler oil and housing with synthetic, but hotter gears.

Would like to see the data they based the opinions on. I have seen stuff in the past that made Lucas gear oil look like a last place finisher and not something I would grab first.

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[ShadowsPapa]

Currie says non-synthetic clings better.

https://www.currieenterprises.com/w..._1AHo3veqx6YO1SkkI44WYZq2j8l2hCInWuyOAENwpz2m

Funny thing - discussions about that mention them, and then say they are the only ones that say that. But I'm not sure what "clinging" would do for a benefit. It's going to have a good thick film in any case.

I use Valvoline synthetic in my JT Mojave.

ECGS built me a HD Dana 44 rear axle for my JK Rubicon. It came with a 5-year warranty as long as I used Lucas 85W-140 conventional gear oil.

Here is what they say about gear oil selection:
https://eastcoastgearsupply.com/files/PDF Files/ecgs-gear-oil-recommendation1.pdf

That one is all over the place.
And they are dead wrong about this specific area - science proves them wrong, as do actual machinery experts -

Regular non-synthetic will absolutely emulsify - take in the water and not separate easily. Synthetic resists emulsification. I don't know where they heck they got that info. I've seen many - dozens if not hundreds, of differentials and manual transmissions with an emulsion in them - and it lasts.

Generally speaking, synthetics hold their viscosity better than non-synthetic.

 

[Wheelin98TJ]

Funny thing - discussions about that mention them, and then say they are the only ones that say that. But I'm not sure what "clinging" would do for a benefit. It's going to have a good thick film in any case.



That one is all over the place.
And they are dead wrong about this specific area - science proves them wrong, as do actual machinery experts -

Regular non-synthetic will absolutely emulsify - take in the water and not separate easily. Synthetic resists emulsification. I don't know where they heck they got that info. I've seen many - dozens if not hundreds, of differentials and manual transmissions with an emulsion in them - and it lasts.

Generally speaking, synthetics hold their viscosity better than non-synthetic.

Currie was seeing higher failure rates with synthetic. So they built a dyno and did some testing.

I personally don't have a preference. If it's under warranty, I just run whatever they say to run.

 

[ShadowsPapa]

Currie was seeing higher failure rates with synthetic. So they built a dyno and did some testing.

I personally don't have a preference. If it's under warranty, I just run whatever they say to run.

A lot depends on the synthetic itself.

But all of the lube experts, makers of the lube, machinery sites and others say the same things -
synthetic oil is non-hydrolytic. In other words, they remain stable in damp environments as they do not emulsion when exposed to water.

For heat conductivity - there's a huge difference in the types and qualities of synthetics. To suggest that "synthetics make gears run hotter" is like saying "it's cloudy so it must be raining".

Here's from a person who has researched this -
H = F.rho.c(To-Ti),
where H is heat energy in Joules, F is volume flow in cubic meters/s,
c is heat capacity in Joules/kg.C, and temps in C. The c for synthetic oil is 2000 J/kg.C and c for dino is 1780 J/kg.C. I assumed a flow rate was 1/4 liter per second, To is temp out of a journal bearing = 100 C, and Ti was oil temp into bearing = 80C, representing a temp rise of 20C, which is a rule of thumb.

Hs = convective energy transfer in Joules for synthetic = 10.65 J
Hd = convective energy transfer in Joules for dino (mineral oil) = 9.3 J.

Therefore, a PAO majority synthetic oil is 13% more efficient at convective heat transfer.

Some trucks and heavy equipment specify synthetic only. Some vehicles have that marked right on the differential.

Eaton Corp released a document (TC-019-R2) on this subject in 8/93 after a decade of development, field testing and Warranty research. They firmly endorsed synthetic lubricants in their products - for (briefly) the following reasons;

1 Extend Warranty for up to 7 years or 750 000 miles
2 "Because synthetic lubricants run cooler than mineral-based lubricants...."
3 Savings on fuel ranging from 1% to 5% ("...assume at least 1%")
4 Extended OCIs
5 Longer service life of seals and bearings

Sometimes there is a lot assumed, lumping things together instead of looking at types. Many truck manufacturers and other heavy equipment manufacturers are actually specifying it - and some are extending warranties if it's used.

Machinery design sites also talk of the reduction in friction, superior film between the gear faces and so on. If the film is better, thicker and slicker, hard to see how gears would run hotter. I suspect they looked at only one group or type and then said "they are all bad".

 

[Wheelin98TJ]

...I suspect they looked at only one group or type and then said "they are all bad".

I can't say for sure, but I don't think Currie would go through the trouble of building a dyno and then only do limited testing with it.

There is a Currie branded full synthetic gear oil. They probably don't think that stuff is bad.

 

[ShadowsPapa]

I can't say for sure, but I don't think Currie would go through the trouble of building a dyno and then only do limited testing with it.

There is a Currie branded full synthetic gear oil. They probably don't think that stuff is bad.

LOL - so they are all bad, except their own! And they all cause gears to run hot - except their own!
OK, that makes total sense

You should see the quotes I saw about "Jeep forums" when digging a bit deeper into this - basing everything on what one company says vs. all of the books and studies on the topic. Reminds me of batteries.

 

[Wheelin98TJ]

LOL - so they are all bad, except their own! And they all cause gears to run hot - except their own!
OK, that makes total sense

You should see the quotes I saw about "Jeep forums" when digging a bit deeper into this - basing everything on what one company says vs. all of the books and studies on the topic. Reminds me of batteries.

There is more than one company that recommends mineral based. Dynatrac also usually recommends mineral based.




But most important, if you have a warranty and want to keep it, you should use whatever the manufacturer recommends.

 

[OldButStillJeeping]

Nice, another oil thread.

I trust Dynatrac, and Currie. Good stuff, no doubt. Although I prefer Dynatrac as a personal preferrence. If I had Currie or Dyna's axles I would run what they recommend.

But in my JT axles at my recent diff fluid change, I used Amzoil full syn in the squeeze bags. Those squeeze bags are so simple.

 

[ShadowsPapa]

Might be covering their tails in case someone uses an inferior synthetic.
Who knows, but the science out there contradicts them.

In any case, if they have a specified lube for their product since they warrant it - use what they say! They are the ones covering it, it's their money in the end.

 

[JTGuy]

I run Torco 85-140 GL-6 RGO, that's a non synthetic oil rated GL-6. Torco is old school and so am I. All my teeth are still good.

 

[ShadowsPapa]

I run Torco 85-140 GL-6 RGO, that's a non synthetic oil rated GL-6. Torco is old school and so am I. All my teeth are still good.

I have a feeling there's a lot of over-thinking going into this.........

I also take it that you brush and floss daily?

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