BLACK Rear Differential Oil - Should I be worried?

[econhonda]

So I just got around to servicing my rear diff for the first time since purchasing my 4runner a year ago. I know. I know. This should have happened long ago, but it is what it is. Well, when I pulled the drain plug, black fluid began pouring out. Like really black. Anybody have this happen? Is this something I should be worried about? I do have an elocker so I don't know if that contributed, but it made me a little nervous to see such dark fluid. The new stuff is now in, but I'm thinking about servicing it again in about 1,000 miles just to make sure all of the old fluid is gone.

 

[MrBobDobalina]

So I just got around to servicing my rear diff for the first time since purchasing my 4runner a year ago. I know. I know. This should have happened long ago, but it is what it is. Well, when I pulled the drain plug, black fluid began pouring out. Like really black. Anybody have this happen? Is this something I should be worried about? I do have an elocker so I don't know if that contributed, but it made me a little nervous to see such dark fluid. The new stuff is now in, but I'm thinking about servicing it again in about 1,000 miles just to make sure all of the old fluid is gone.

How much metal was on the drain plug and did you notice any metal chunks/debris in the oil as it poured out? If some fine metal was built up on the plug and no chunks in the oil as it drained, I'd say you are safe. I am changing mine tomorrow. I have about 130k and I am not sure if it's been done before or not...

 

[quicksilvr]

Yeah, they can get pretty nasty. Mine was blackish green when I drained it last year. Like he said, if there are no chunks of metal or big flakes, you're fine. There should just be a nice paste of metal slime on the magnet.

Since it is fairly easy to drain and refill, it can't hurt to do it again in a bit. Especially if it makes you sleep better at night. I know that's how I am....lol.

 

[econhonda]

Thanks for the responses. There was actually almost no metal at all on the drain plug so I guess that's a good sign. I tested out the elocker last night and it turns on and off WAY easier now. I used to have to put it in reverse, back up a little, and then it would lock. Hopefully the t-case and front diff look a little better when I get around to servicing them.

 

[Mr. Leary]

Had black fluid in the front diff on my 80 series. I'm sure that its not good for it, but those diffs are pretty difficult to booger.

 

[cfranck1]

As long as there was no big chunks of metal and just some shavings on the drain plug. You should be good.
As they say "Dirty oil is better then No oil"