Front Diff Fluid Looks Bad

[Gebo]

Just changing my diffs and transfer case fluids on my ‘23 GX460 with 25k miles.

Started with rear. Drained fluid basically clear golden brown. Very little metal on drain plug magnet. Transfer case clear yellow brown.

Front diff gray fluid with lots of metal on magnet.

Sorta concerning.

Only 25k? Never been off-road.

Is this normal for first time drain? Would the front diff have more “pressure” on it as compared to the rear?

 

[tcp71]

Often the front differential isn’t turning and heating up while driving to burn off condensation which turns it grey.

 

[JHZR2]

common ime

 

[02SE]

Your GX460 is Full-time 4wd. So if the vehicle is moving, the front is also turning. What you described is typical of factory fill gear oil. Break-in of the gears etc leads to what you saw. I'm going to bet that the prior owner had the rear axle gear oil changed at some point, but didn't change the front differential.

The transfer case gear oil doesn't get as loaded with debris, because there are no hypoid gears in it.

Put in new gear oil and drive on.

 

[ripcord]

Often the front differential isn’t turning and heating up while driving to burn off condensation which turns it grey.

I'm pretty sure his GX460 has full time AWD.

 

[Mainia]

Just changing my diffs and transfer case fluids on my ‘23 GX460 with 25k miles.

Started with rear. Drained fluid basically clear golden brown. Very little metal on drain plug magnet. Transfer case clear yellow brown.

Front diff gray fluid with lots of metal on magnet.

Sorta concerning.

Only 25k? Never been off-road.

Is this normal for first time drain? Would the front diff have more “pressure” on it as compared to the rear?

Normal, nothing to worry about. You did it at the right time for that car. My wife’s 2014 RAV4 rear differential was jet black at 22,000 miles. A leased car, from a lady with no soccer mom hauling as the rear seating plastic and rear hatch plastic was showroom condition. No hitch. Could not believe it, and when I drained the crap WS transmission fluid at 25,000 it was so burnt and stunk up the 24x48 ft garage in winter I had to leave the garage for awhile I got sick from the smell. Something tells me the lady had a very heavy foot.

 

[edyvw]

Just changing my diffs and transfer case fluids on my ‘23 GX460 with 25k miles.

Started with rear. Drained fluid basically clear golden brown. Very little metal on drain plug magnet. Transfer case clear yellow brown.

Front diff gray fluid with lots of metal on magnet.

Sorta concerning.

Only 25k? Never been off-road.

Is this normal for first time drain? Would the front diff have more “pressure” on it as compared to the rear?

Nothing to worry. It is full time AWD and front differential will be exposed to more heat due to engine temperature.
On my BMW, the front fluid looks bad when changing, and the rear looks like I drained brand-new fluid.

 

[Toyotech454]

Just changing my diffs and transfer case fluids on my ‘23 GX460 with 25k miles.

Started with rear. Drained fluid basically clear golden brown. Very little metal on drain plug magnet. Transfer case clear yellow brown.

Front diff gray fluid with lots of metal on magnet.

Sorta concerning.

Only 25k? Never been off-road.

Is this normal for first time drain? Would the front diff have more “pressure” on it as compared to the rear?

I drain factory front diff fluid out of Toyotas on a regular basis, it always comes out somewhat grey, the rear diff and transfer case always comes out amber, couldn't tell you why, but your experience is normal. I wouldn't worry.

 

[02SE]

I drain factory front diff fluid out of Toyotas on a regular basis, it always comes out somewhat grey, the rear diff and transfer case always comes out amber, couldn't tell you why, but your experience is normal. I wouldn't worry.

That's surprising to hear. Every Toyota I serviced back in the day as a Tech at Toyota, and all of the ones I've owned, the diffs that were always driving the vehicle, the factory fill would come out as described. Front and rear on Full-Time 4wd's, and the rear on Part-Time 4wd's. The Part-Time 4wd front diffs would look similar if the owner engaged 4wd often.

 

[Gebo]

I drain factory front diff fluid out of Toyotas on a regular basis, it always comes out somewhat grey, the rear diff and transfer case always comes out amber, couldn't tell you why, but your experience is normal. I wouldn't worry.

Ok, I can go back to sleep. Thank you

 

[D1dad]

I did our 18 rogue awd @ 40k and mine was the same. I couldn’t get out from under the car cause I was dry heaving. I’ve learned that once a year or so is the sweet spot on this thing. It holds so little that 40k would be equal to 100k on a bigger ride. I do the rear every other time cause it’s always spotless with a bit of sludge on the magnet.

 

[Gebo]

I did our 18 rogue awd @ 40k and mine was the same. I couldn’t get out from under the car cause I was dry heaving. I’ve learned that once a year or so is the sweet spot on this thing. It holds so little that 40k would be equal to 100k on a bigger ride. I do the rear every other time cause it’s always spotless with a bit of sludge on the magnet.

So the front gets a lot “dirtier”? I wonder why?

 

[Fredward]

I just did both differentials and the transfer case on my 2018 Tacoma 3.5L TRD-Sport at 44k miles. It was the first change for the front differential and TC. I saw the same thing. The front diff fluid looked pretty rough, like liquid iron, and there was a lot of gunk on the drain plug magnet.

The rear diff fluid looked just fine, but I changed it at 7k to get the break-in material out, so this was the second change. TC fluid looked fine as well, factory fill.

 

[burbguy82]

Just changing my diffs and transfer case fluids on my ‘23 GX460 with 25k miles.

Started with rear. Drained fluid basically clear golden brown. Very little metal on drain plug magnet. Transfer case clear yellow brown.

Front diff gray fluid with lots of metal on magnet.

Sorta concerning.

Only 25k? Never been off-road.

Is this normal for first time drain? Would the front diff have more “pressure” on it as compared to the rear?

good thing you drained it. To be honest, I would not worry about it. Drain or check the front in the next 5000 and see what it looks like. The diff is likely the most reliable thing on any car, and can take a bunch of abuse.

I would and do choose 75/90wt over the factor 75w85 however. No reason other than I am on the thick crew here on bitog....next fill on mine will be 75/110

 

[thescreensavers]

When I did my diffs, My Front Diff was also the dirtiest/worse looking fluid of the 3.

I'd also get a drain and fill of your trans while you are there. Magnefine+ Hayden678 if you really want to step it up.

 

[Gebo]

Thank yall for sharing with me. Fredward, your description of "liquid iron" is spot on. That is exactly what it looked like. I am so dang messed up, I did 2 more D&F's. I used Amsoil 75W-90 in both my diffs and HPL's 75W in the TC.

 

[dubber09]

That's why I did TX case and rear diff oil changes early at 20k miles on Sportage, now doing 30k miles changes and used oil looks good.

 

[Gebo]

I’m with you!

 

[Gebo]

I know y’all are tired of me saying it but…..

Does anyone know why the front diff fluid looks like “liquid iron” after 25k miles?

Inquisitive mind wants to know.

 

[burbguy82]

I know y’all are tired of me saying it but…..

Does anyone know why the front diff fluid looks like “liquid iron” after 25k miles?

Inquisitive mind wants to know.

wear or contamination or both