Front/Rear Differentials Changed at 14k Miles

[JerryBob]

Replaced the factory front/rear diff oil on my 2011 Tacoma that has 14k miles. I mostly take public transportation during the work week, hence the low miles.

I filled to Amsoil Synthetic Severe 75w90. Toyota calls for 75w85. Redline is the only 75w85 I can find in synthetic, and they wanted $28 for shipping. Amazon sells it, but is back-ordered.

Rear drain plug has a few shards and flakes (link to pic below). Also noticed what appears to be sludge on the plug. Front plug had sludge but hardly any metal.

The old rear differential oil was nice and amber-colored. The front was cloudy, gray, and smelled. Maybe it had gotten wet at some point.

Anyway, no questions here - just posting for reference.

 

[Donald]

I think a UOA of the front is in order.

 

[JerryBob]

Originally Posted By: Donald
I think a UOA of the front is in order.


Unfortunately, I drained into the same container as the rear. Since it only takes 2 quarts, I may do it again in a year or two.

 

[JHZR2]

I noticed the same thing on my chevy when I did the front diff for the first time. No power transmitted means it is easy to get condensation. Ill bet that diffs arent well sealed from the environment, and they breathe with temperature fluctuations...

 

[andyd]

Check the vent tubes. Both diffs require a vent. It is usually led away to the top of the frame. The Rat has a drippy gasket on the front diff. It is my chassis anti rust system. It is constantly being replenished. The rate is slow enough that it will have to get much worse before I fix it.

 

[friendly_jacek]

What you call sludge are fine particles of steel. Graphite-like.

 

[CarbonSteel]

My FX4 had similar colored oils when I changed the FF at 13,300.

This was the rear:

This was the front:

I UOA'ed both and there was no moisture in either of them. They both had a horrible odor and I chalk that up to some of the additives. There is likely nothing to worry about, but YMMV

 

[BISCUT]

Same here when I did the 10 Armada at 30k. Wish I had done earlier. But I did pull the plug to see the magnet and it was very clean. Part of break in I guess.

 

[JerryBob]

Originally Posted By: friendly_jacek
What you call sludge are fine particles of steel. Graphite-like.


I wondered about that. But since they wiped off so easily, it didn't seem like they were attracted to the magnet.

Fine particles normal?

 

[JerryBob]

Originally Posted By: 2010_FX4
My FX4 had similar colored oils when I changed the FF at 13,300.

This was the rear:

My front looked very much like your rear diff - grayish. That's a strange honey-mustard color on the front.

Since it is not a huge outlay, I'll probably start changing the front every couple of years.

Going to do the manual trans and transfer case with Redline GL4 next weekend.

 

[Zaedock]

Looks normal to me. You have to remember that these are mass - produced axle housings and go out the door like hotcakes. Millions of units live their full service life without any fluid change at all.

Regarding the color and particles, the semi float rear fluid also lubricates the outer wheel bearings. Then you also have to consider that the rear housing on Yota's are welded steel with third members and the front is aluminum.

 

[Jim Allen]

I say normal. My Ford F150 at 11k was just the same. Several things to consider here:

-If you have never (or not much) used four wheel drive, then the front oil didn't get used much and might not have changed color in use as the rear did.

-The diffs do most of their break-in a metal-shedding during break in. SInce their are no oil filters in there, the oil is highly contaminated with break-in material. It's good that you got that out for long term life. Seeing metal chips and such is normal at this point.

-Some manufacturers use different factory fill (FF) oil front and rear, so the appearance could be different. I don't know if this is the case with Toyota. Some mfrs use a different viscosity oil front and rear so the oil may look different for that reason and even smell different, if they use different additives (FMs for a LSD, for example).

-The difference in housing material as Zaedock wisely pointed out above can result in a different color. I don't know why that is but I have seen it several times.

- You will be wasting your money changing the front oil every couple of years. Condensation is seldom an issue in front diffs. I've seen and worked on a lot of front diffs in 4x4s and almost never saw it. I changed the oil in a 1958 Jeep that had never been changed and had almost never been put into 4wd and the diff had no condensation or signs of it. I suggest you UOA at the time you intended to change the oil and prove that to yourself.