ajsturtz

Hmmmm... I'm at 160k on my original fluid, maybe I'll change it at 200k, or 250k lol...

rsylvstr

Does the cover have to be removed to do that?

Merlyn

Follow the procedure in this video:

Spent a couple of bucks and purchased a fluid extractor, took longer than him to remove fluid but only because I bought a economy model. Other than that the job went smooth.

[F2C]MaDMaXX

(Yes, older thread, but seems people aren't even changing it after the 150k miles that Ford say it needs it at)

I too bought the economy model he recommended, worked well tonight in sucking out some nasty looking fluid - there was the yellowish coloured stuff he said was some gear bedding stuff, mixed with a little water which was likely condensation, but the rest of it was/is a grey colour, not even close to the golden translucent colour of the new stuff.
Still have to make sure there's nothing else left in any corners before i fill it tomorrow.

tcp2

Because the front differential is only turning in 4wd or 4A (in lariat and above trims) it rarely has a chance to evaporate the humidity that builds up in the fluid. Every F150 front differential I have ever changed the fluid on comes out looking like coffee with cream. Unless you heat the oil up over 212F and burn off the water, it will look like that. It's normal for these trucks and doesn't seem to affect longevity. My method is always to pull out the fluid with a pump and replace with the same. Run the truck a bit in 4Hi before you do it to stir up any contaminants and suck them out.

Augster

Just as there are many threads in this forum suggesting it's water-fouled, there are many other threads and videos on the internet that indicate this murky color is a result of the marking compound used by Ford for backlash setup.

Perhaps it's a combination of both, but since this is such a common experience, I would tend to believe it's marking compound since the humidity factor shouldn't apply to dry, hot locales which have also reported experiencing this phenomena.

I will be changing out the cover of my recently acquired 2014 Raptor axle, which has resided here in low-humidity SoCal all its life so I will find out soon enough if it, too, dumps out this mucky oil...

2013_XLT

i had the same problem and had a hell of a time getting it fixed, even under warranty.

https://www.f150forum.com/f38/front-...464879/index4/

[F2C]MaDMaXX

Yeah i'm using the pump out method, seemed to work well, got about 2qts out which is correct, though i just let it sit overnight to any remaining to drain down off the gears before sucking out anything left.

One thing i will add, is that, at least on my Lariat, the front diff is being turned, albeit without load, even in 2hi, due to fluid wash it seems. (ran a gopro on the front axles, confirmed hubs weren't locked but axles still turning)

[F2C]MaDMaXX

Fordtech guy says the yellow is the marking compound, shrug, sounds legit. The grey is what i'm looking at, that's some pretty crappy worn fluid right there, i can't say if it's just wear/pure dirt and/or water contamination over the years or what. Needs changing for sure
Don't forget, even dry locations will get condensation, it has an open breather and it sits under a very hot engine, yet can be in the airflow and is a mass of gear fluid. Condensation will/can still happen in dry climates, it's temperature differential. *Rimshot*

Augster

True about condensation in general but I'm of the opinion the small breather tube relative to the 2.5 quarts of gear oil would require a significant amount of condensation to develop the sheer amount of discoloration of the oil that many have shown in said dry climate, and we have no idea of the true average temperature disparity of the air surrounding the breather inlet and within the axle housing during normal driving conditions. We must realize that each situation is unique, with time, environment, and usage being the primary factors involved, but for the most part, I disagree with the general speculation that condensation is the root cause.

But we're all just postulating W.A.G.s! Only a controlled testing setup and analysis could provide the undisputed scientific answer we are all searching for...

Nothing but 'net...