Material on drain plug and red fluid in transfer case

[terdwrassler]

So I was doing the diff/TC fluid changes today before winter and I noticed the fluid in the transfer case was red. Could some dummy have accidentally put AT fluid in? More worryingly, I found some metallic debris on my drain plug in the rear. Is this enough to cause concern?

 

[737AMT]

We don't have a lot to go on as far your vehicle information goes, but ATF in transfer cases is not uncommon. Same goes for the metallic looking sludge that accumulates on the the magnets. What I see on the plug itself wouldn't give me any cause for concern. Did that little shiny piece off by itself to the left of the magnet come out of the differential, or is that some debris that was on the ground when you took the picture? Even if that is a chunk of metal, I still wouldn't go tearing the diff apart if it's not making strange noises. Sometimes what looks like a small piece of metal is actually a chunk of that same metallic sludge. If you can crush that piece, then that's all it is.

 

[terdwrassler]

Sorry but it's a 98 3.4 L 4Runner with 236k. That big chunk is solid I just pulled it off the magnet. I knew some fine metallic sludge is common but I thought the fragments may have been excessive.

 

[737AMT]

I'm assuming you've reinstalled the plug and put the vehicle back in service by now. If you haven't, I'd try to swab around the inside of housing as best as possible through the drain plug hole to see if there's any more larger pieces sitting in the bottom of the housing. If you decided to put the plug back in and go on your way, I would step up the maintenance intervals. Perhaps do a drain and refill of the diff to check the magnet every second or third time you change the engine oil. If you don't find any more chunks like after that about two or three times, I'd check it again in six months, and then go back to the regular interval.

 

[Rschmidt17]

Yeah I agree with 737