Regearing to 4.88.. what oil do you guys use?

[Odyssey USA]

Without knowing the two temperatures (oil and gear set), it is not possible to glean much from their statements. In the end, synthetic oils handle heat and cold much better than conventionals and the oil in the housing is typically 10°-20°F cooler than the contact points of the gears.

With that said, they would seriously need to pony up some data that quantifies any of their statements related to synthetic oils causing failures and synthetics not handling heat transfer as well as conventionals (thereby suggesting or stating that synthetics do not protect as well as conventional oils).

^^^^

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[DanW]

I’m no scientist and was full on synthetic for diffs too until I read that. Not sure how they came up with that conclusion but I don’t see a company like Currie just saying that for no reason. They did warranty all cases and took care of their customers when it happened though.

I've read that dino gear oil is better for break-in, but not for heat transfer reasons, but rather to allow slightly more friction for the teeth to seat with each other. So they may have the right move for the incorrect reason.

Viscosity would have more to do with heat transfer than whether it is synthetic or not. So a 75w90 synthetic will be a 90 weight when fully up to temp. an 80w90 will actually not transfer heat as well when cooler but when fully up to temp should be the same as a synthetic with the same viscosity rating, only differing slightly depending on the brand and formulation.

So I'd bet they solved the problem for other reasons than what they are stating. But I'm also not a chemical engineer. But I doubt Curry has one, either.

But it is still a fact that many OEM's put synthetic gear oil in the diffs straight from the factory. And they DO have engineering resources to know if that's ok or not.

 

[Qjoh5510]

Without knowing the two temperatures (oil and gear set), it is not possible to glean much from their statements. In the end, synthetic oils handle heat and cold much better than conventionals and the oil in the housing is typically 10°-20°F cooler than the contact points of the gears.

With that said, they would seriously need to pony up some data that quantifies any of their statements related to synthetic oils causing failures and synthetics not handling heat transfer as well as conventionals (thereby suggesting or stating that synthetics do not protect as well as conventional oils).

That’s exactly what they did though. Got 2 separate temps during normal operation. Don’t ask me for the numbers because I don’t know but I wanna say they may know what they’re doing lol.

 

[CarbonSteel]

That’s exactly what they did though. Got 2 separate temps during normal operation. Don’t ask me for the numbers because I don’t know but I wanna say they may know what they’re doing lol.

I am not trying to say they do not know what they are doing. I am saying without the numbers as compared to known standards and testing methodologies, testing the oils, trending over periods of time, and the like that this is all "finger in the air stuff".

Anecdotally speaking, there are MILLIONS of axles on the roadways that have synthetic oil in them from the factory that perform just fine for hundreds of thousands of miles under harsher loads than those experienced in a Jeep--so their "theory" (and that's all it is without data that has been validated) does not wash.

 

[JimLee]

Dynatrac recommends mineral based, they say it's because "some synthetic oils have properties that can reduce flow of oil through the axle housing". That being said, Dynatrac axles have a second sump that most other axles do not have (at least on their 60's they do), they also said "some" meaning not all but they did not specify any brands. Don't really care about any anecdotes or opinions, I will run mineral based because that is what the manufacturer recommends, and they hold the warranty on my axles.

 

[Carlton]

I've regeared many jeeps and won't use anything but Crisco.

 

[CarbonSteel]

Dynatrac recommends mineral based, they say it's because "some synthetic oils have properties that can reduce flow of oil through the axle housing". That being said, Dynatrac axles have a second sump that most other axles do not have (at least on their 60's they do), they also said "some" meaning not all but they did not specify any brands. Don't really care about any anecdotes or opinions, I will run mineral based because that is what the manufacturer recommends, and they hold the warranty on my axles.

Perfect description of conventional oil at cold temperatures--even the 80W-90 that Dynatrac recommends for cold temperature use. At the end of the day and provided the viscosity matches the use case and work load, one could hardly go wrong picking any GL-5 oil and running it.

 

[Gorilla57]

I read on a Jeep forum (can't remember which one) that had a response from Currie. They said the gear manufacturer said use dino oil. But no one has figured out which company this was because all of the gear companies say use synthetic. So.....who's actually full of BS? Currie or their gear supplier....?

 

[Vinman]

Currie has been building performance differentials since 1959. I think it’s safe to say they know what they are talking about and they don’t benefit at all from recommending the less expensive dino oil.
Now Jeep does benefit using synthetic oil by bringing the overall fuel economy numbers down and the oil manufacturers benefit by selling the more expensive oil.
Just my opinion

 

[omnitonic]

Anecdotally speaking, there are MILLIONS of axles on the roadways that have synthetic oil in them from the factory that perform just fine for hundreds of thousands of miles under harsher loads than those experienced in a Jeep

Yeah, I mean basically every big truck made for a long time now. I'm not sure when they switched over, but my old truck definitely had synthetic gear oil everywhere, and the last time I checked, it had 600,000 miles on the clock.

I am bored, so I wasted a chunk of my life scrounging around for information about what kind of axles this truck actually has. They're Dana Advan-Teks, same as our Jeeps.

That's kind of fascinating, actually. Obviously, the axles on my class 8 road tractor are a tiny bit more beefy than the good old Dana 44. It looks like they have about 420mm ring gears. The pumpkins are as big as, well, pumpkins. Big pumpkins at that.

I tell y'all what. I have off-roaded in a Jeep, and I have off-roaded in an 18-wheeler, and I will take the Jeep every time. Getting a big truck off pavement is a bad, bad day. I've been there several times over the years, and no, this is all within the spectrum of shit that happens to drivers who are awake.

Ha, I know this is TOTALLY off-topic, but honestly, I'm a little drunk at the moment. Well, I'm approaching drunk fast, while still hovering in the tipsy zone. Anyway, I was in Greensboro, NC last week, driving through a pitch black gravel parking lot in the dark, when I made a little discovery. One of those mud puddles is pretty damn deep.

The guy who eventually showed up to get me out of that hole laughed his ass off about the million dollar mud hole. He knew of its existence. He did not use a Warn 10,000 lb. winch to pull me free, but the principles of recovery were pretty much the same. It was kind of interesting, except the part where I sat there for three hours with my thumb up my ass, waiting on his hilarious ass to show up.

For the record, I did NOT lose my safety bonus, and the company did NOT consider this an accident. They chucked it up to shit happens, and that's exactly what it was. I hope they bill the shipper for this one, because having a mud hole like this in a parking lot designed for 18-wheelers is unmitigated bullshit.

So yeah, totally off-topic. If this was Facebook, I would get a 30 day ban for posting this. Hopefully this forum is more forgiving.

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