Oil Dirty Front Differential @26k miles

So I did my differential (front/back) and transfer case service myself @ 26k miles on my 2021 Tacoma TRD OFR I bought it new with 6 miles.

I noticed my front diff was dirty and sludgy no metal shavings though. Anyone experience anything similar? Could it be the original diff oil is just shit or maybe it heats up quicker because it’s less volume of oil? TIA

 

The front looked worse than the rear? If not, it is normal that it look dirty even though the front is not used as much as the rear.

 

The front would look clumpier as it’s not used as much or heated as much but shouldn’t be dirtier

 

My 09 looked awful the first time i changed it @ 15K..after that it looked ok ...

 

That's normal. Due to the much lower quantity and that it is always spinning, it should be changed with the rear diff.

 

I changed all my fluids at 5k and was surprised to find more sludge in my front then the rear.

 

Yea the front was worse than the rear. After I flushed it I filled it with Redline 85W for both rear and front. I’ll re-do the front again in about another 10k to see the condition I’ll post that update as well.

 

The internals are always spun by the front drivers wheel due to the CV and the way the drivetrain is setup in these trucks.

I noticed some very fine sludge in my front diff when I did my 60k service. Unknown history before that. Roughly the same at 90k so I am not worried about it.

 

It doesn't take a lot, but you can just pull the filler and judge what comes out from there. If you do it with a warm engine, there will be overflow. Or, you could dip in a white strip to get a visual.

For reference, see the pics here:

https://www.tacomaworld.com/threads...-manual-transmission-6mt-fluid-change.481719/

 

Did all my gearbox oils recently the front diff was definitely the worst. My guess is that the smaller volume means anything in the oil is less diluted than in the other cases.

Correct me if I'm wrong but my understanding is that the front left axle isn't disconnected so even when not four-wheel drive the front diff is still getting turned.

 

Exactly

 

There was a theory that the factory fill contains some additives for break-in that darkens it?


I'm at 90k and am about ready to do the second swap. Did the first at 7k and checked them at 60k.

 

I can tell you my gen1 tundras front differential gear oil was dirty looking at that mileage, but the rear was still pretty clean. My tacoma should be coming up for a gear oil change next year....we'll see how it goes.

 

Hadnt heard that one myself. As I said above, I recall some sludge at both 60k and 90k. Even sent a sample to Blackstone at 90k. No issues according to them, other than water intrusion. Which I knew about.

 

That's what theories are all about. Hahaha!

Overall, it's a diff with no filter. Seeing things in the used fluid shouldn't be a surprise, although seeing it come out more like virgin fluid is always welcome.

 

Yes, my front diff was black and sludgy compared to almost brand new looking fluid in the rear. Changed mine at 18k miles.

 

I would go longer than 10k on redline fluid…

 

Agree

 

Pretty sure Toyota recommends 30k between service