Grayish rear diff fluid

amir_gh

amir_gh

New member
Hello,

I replaced my rear diff fluid on my 2016 limited with 48k miles . Mine took about 3 quarts. Oil condition was absolutely terrible. It was grayish color. Never seen that before. Does that grayish color mean anything?

Thanks
 
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sounds like maybe some water got into the diff thru the breather? Either that or you are cooking fluid. are u running 6s down the 1/4?
 
bak3rme said:
sounds like maybe some water got into the diff thru the breather? Either that or you are cooking fluid. are u running 6s down the 1/4?
Click to expand...

Got my truck used. Everything is stock. No modifications. Previews owner never replaced it
 
I'd say get underneath and look on top of the diff for the diff breather. is there fluid coming out from that area? My guess is that maybe water somehow went through there and mixed with diff fluid. Interested to hear what others have to say about this.
 
Sounds like water contamination. It wouldn't necessarily have to come in through the breather. If the rear was hot and took a trip through a nice cold stream, water can be pulled in by vacuum through the rear axle. This is why people install elevated rear breathers that stay open to atmosphere.
 
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Almost guaranteed water intrusion. As noted above, check the breather for possible intrusion. If all appears OK, I would run it for a bit and service it again to be sure the fluid looks OK, or at minimum pull a sample to inspect. 20+ years in the business so I am going off some experience when I type this. Best to you.
 
sawman1 said:
Almost guaranteed water intrusion. As noted above, check the breather for possible intrusion. If all appears OK, I would run it for a bit and service it again to be sure the fluid looks OK, or at minimum pull a sample to inspect. 20+ years in the business so I am going off some experience when I type this. Best to you.
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Thanks. I will keep eye on it.
 
bak3rme said:
I'd say get underneath and look on top of the diff for the diff breather. is there fluid coming out from that area? My guess is that maybe water somehow went through there and mixed with diff fluid. Interested to hear what others have to say about this.
Click to expand...

Any suggestions for Diff breather kit? Can I do this myself?

Thanks
 
amir_gh said:
Hello,

I replaced my rear diff fluid on my 2016 limited with 48k miles . Mine took about 3 quarts. Oil condition was absolutely terrible. It was grayish color. Never seen that before. Does that grayish color mean anything?

Thanks
Click to expand...

I did mine after ten years. Color was pitch black. Gray might indicate some moisture, might not mean anything.

Check it in three years again.
 
Greyish diff fluid in a 4runner is hardly enough evidence to say it may be a flood vehicle.

As other mentioned, if you went through a water crossing or even big enough puddle on road water could have gotten in. I would change again in like 10k miles and check since it's easy enough to do.

I did the ARB diff breather kit just because it was already all pieced together but there's a few cheaper ways to get the breather and bung from Toyota and use fuel line to run up to engine bay or near gas filler.

Amazon.com: ARB Differential Breather Kit (170112): Automotive
 
Water intrusion during some type of water crossing IS the most likely culprit, doesn't have to be off road.

If there's water in one diff, as others said I'd check everything else, too.

PO wasn't from Houston, was he?
 
amir_gh said:
Hello,

I replaced my rear diff fluid on my 2016 limited with 48k miles . Mine took about 3 quarts. Oil condition was absolutely terrible. It was grayish color. Never seen that before. Does that grayish color mean anything?

Thanks
Click to expand...

Was it more like graphite, or milky?

Graphite color is OK. Milky means water.
 
delloro said:
Was it more like graphite, or milky?



Graphite color is OK. Milky means water.
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Yeah, after almost 90k on factory fluid I'd suspect a little bit of metal flakes in there, almost like the color of never seize. I wouldn't rule out water intrusion though either and I'd bet you're good for a while now that it's all cleaned up and fresh.
 
Typical the first time you change it. Metal flakes from the unused gears. Should be cleaner when you change it at 100k.
 
pDubs said:
Greyish diff fluid in a 4runner is hardly enough evidence to say it may be a flood vehicle.

As other mentioned, if you went through a water crossing or even big enough puddle on road water could have gotten in. I would change again in like 10k miles and check since it's easy enough to do.

I did the ARB diff breather kit just because it was already all pieced together but there's a few cheaper ways to get the breather and bung from Toyota and use fuel line to run up to engine bay or near gas filler.

Amazon.com: ARB Differential Breather Kit (170112): Automotive
Click to expand...
No need to buy that kit. Just buy the threaded nipple from amazon and &20 worth of fuel hose from Napa. You can search for breather mod on this site, there are many walk throughs
 
There are threads on diff breather mods. Check the stickies or search. A couple of different ways to do it. One guy routed his up to the fuel door and included all the parts he used, as I remember.
 
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