Ford F-350 Front Differential OCI ?

[JWC86]

2020 f350, Dana “Super” 60 front diff.

Changed the front and read diff oil at 40,000 miles with Amsoil Severe Gear 75w-90.

It’s at 80,000 miles now and planing to do the rear again and wondering people thoughts on how often to change the front.

For those that don’t know when these trucks are in 2wd and hubs in “auto” the front diff doesn’t spin(or barely spins), truck spends 90% of the miles like this. 10% of the time I run with the hubs locked(the vacuum hubs don’t work well at temps below -20c so I just lock them when it’s that cold) and maybe spends 2% of its life powered in 4wd high.

I’m thinking I could do the front diff oil every second rear diff change, so 80,000 miles.

What does BITOG think?

 

[oldhp]

Probably still come out looking new at 80K.

 

[Bryanccfshr]

I changed my rear at 60 k i am at 88 now with the Tacoma. I have the fluids for,the front. Just haven’t done it yet. Maybe this winter but seriously I doubt I have engaged that front diff for. 1k miles. I don’t drive in deep water or mud so I am not worried. The rear gets the work so every 60-80 k is probably conservative with that.

 

[BrianF]

Every 80k miles sounds like a great number. I'd still check level, metal on the plug at 40 just to be involved.

I'm in a similar boat with my 2017 3500 Ram 3500. It's setup always has a bit of spin in the diff on the driver side. I cannot remember the mileages but the factory fill looked brand new at around 90 ish thousand km. New stuff went in anyways and I'm 60 to 70k on it now. Even when not needed I use 4x4 on the grid roads to spin things up.

 

[jetman]

@JWC86
Think of all the condensation that's collected in there.
Change it.

 

[SubieRubyRoo]

@JWC86
Think of all the condensation that's collected in there.
Change it.

I’ve never seen any water in any differential I’ve changed, that wasn’t changed for submersion.

 

[JWC86]

@JWC86
Think of all the condensation that's collected in there.
Change it.

I don’t think it makes sense to change it because of condensation based off miles. Seems like it would be more of a time thing.

It’s only been in there 1.5 years…

 

[BrianF]

I cannot comment on the op's climate and humidity he might see. But in my own experiences, the only time I have ever seen visible moisture intrusion has been from vehicles that get swamped.

 

[jetman]

Send a sample off for analysis and see what is what.
Here's a used gear oil analysis post I did a couple of yr ago: LINK my gear oil report
The moisture (condensation) is there (not visible) and additives are there to neutralize the negative effects until they can't.
Just like when engine oil gets "short tripped" (not brought up to operating temp) most of the time and shortens oil life.
A differential that isn't passing hp thru it gears most of the time isn't getting hot enough to boil/burn off the moisture, thus becomes an acid bath over time.

 

[BlakeB]

I changed my rear at 60 k i am at 88 now with the Tacoma. I have the fluids for,the front. Just haven’t done it yet. Maybe this winter but seriously I doubt I have engaged that front diff for. 1k miles. I don’t drive in deep water or mud so I am not worried. The rear gets the work so every 60-80 k is probably conservative with that.

I like to change fairly early to get some break in wear out. My brothers 2010 Tacoma had like 43k when I did his for the first time. The rear diff fluid looked like new, but the front diff fluid was nasty. I ran some cheap 80w90 in the front for a couple short changes and then put synthetic 75w90 in after it cleaned up. My mom’s 4Runner was the opposite, it had around 30k and the front diff fluid looked really good but the rear was black and full of metal. It really all depends on how they’re set up, they all wear a little differently.

 

[D60]

There's no way I'd do it, but whatever lets you sleep. I might do my diffs every 100k.

 

[SEBZX79]

On my hotshot trucks we did first change at 50k then every 100k after that. Rear was always every 50k.

 

[JWC86]

On my hotshot trucks we did first change at 50k then every 100k after that. Rear was always every 50k.

That’s what I’m thinking.

 

[JWC86]

Update: I did the rear diff today with about 45k miles on it and it looks almost new. I’d have no issues going longer and won’t be doing the front any time soon.

 

[BrianF]

In my 3500, I did the factory fill in the rear at 48,000km and it came put like grey, aerated water. In went 80w140. It saw lots of heavy towing, at times 33,000lb combined. Changed it again at 100,000km and it came put as clean as it went in. I'll check it again in a couple years.

 

[JWC86]

In my 3500, I did the factory fill in the rear at 48,000km and it came put like grey, aerated water. In went 80w140. It saw lots of heavy towing, at times 33,000lb combined. Changed it again at 100,000km and it came put as clean as it went in. I'll check it again in a couple years.

Similar experience here:
Drained factory fill at 1,500km, it was very grey and had lots of metallic in the oil. Amsoil Severe Gear went in.
Drained again at 58,000km, looked somewhat grey, small amount of metallic material.
Just Drained at 131,000km, looked great, zero greyness and zero perceivable metallic material to the eye. If you told me it was in service for a week I would have believed it.