ATF fluid change when it is dark brown

[labsy]

Hi,

I know this is over and over the similar question, but again, each symptoms are different.
I need to change Automatic Transmission Fluid on my 2006 Pathfinder with 190.000km (120.000 miles) on gauge. It has been changed once in the past by previous owner, and few months ago I changed 4 quarts as that was all I could get at the time.

Today I checked ATF and it is very DARK BROWN and smells intensively like DIFF OIL. Unfortunatelly I don't have Nissan Matic J/S handy to test how it smells brand new. For my taste it does not smell burnt, but how could I know, as I didn't try burnt ATF yet

Now wondering - I will get 16 quarts of Nissan Matic S in 2 weeks, so I can do full FLUSH, replacing all old ATF with new.
But I am afraid a bit - what could fresh ATF do to my tranny, when old one is so darkish brown? Maybe this brown ATF contains so much friction material dissolved that it can provide friction, so after full flush tranny will die.
...or is it high time to flush all those mud out and stop degradation of tranny, since it is not burnt yet?

Any thoughts, ideas?

*** EDIT ***
After some Googling around I found this nice article, showing ATF colors. I just need to find another web page, showing smell of burnt ATF...
http://www.agcoauto.com/content/news/p2_articleid/141

[smj999smj]

I would flush it. The Nissan Matic J tends to look brown after it has some years on it, in my experience. You don't need to purchase the expensive Nissan Matic S. Castol Transmax J Multi Import ATF is the same thing and can be purchased at your auto parts store and Walmart often carries it. In my two R51's, I use Valvoline Maxlife ATF; I get it in a 1-gal. jug from Advance Auto Parts for around $22. It works great and is fully compatible with Matic J and S.

[disallow]

+1 on smj's valvoline recommendation. Been using it for 4 years with no issues. Truck at 260k kms. I've done a drain and fill every year, mostly because I tow my huge travel trailer and it gets abused. Trans shifts like a dream.

[labsy]

Thanx for recommendations, but I've already purchased Nissan Matic S from eBay for US$8.83/qt here: http://www.ebay.co.uk/itm/261968837229? ... EBIDX%3AIT
And seller was kind enough to attach the transmission oil pan gasket for free, which all together is quite a good deal.
Hardly waiting for delivery...

[labsy]

BTW...what about transmission FILTER, did anybody also change that? With its 16 bolts it seems more like a part, which gets replaced during rebuilt, rather than during regular maintenance.
Should I replace filter, too?

[smj999smj]

Nissan transmissions don't have filters; they have screens. There's no need to replace it. If you have enough debris in your trans fluid to clog the screen, then it's time for an overhaul.

[labsy]

Thanx for the info. Could not find such an description in service manual.