Dark ATF can be from the normal wear particles of the clutches' friction material wearing off and from oxidation of the fluid, especially if it has gotten very hot. Tiny dark particles can be the clutch material. Tiny shiny particles are metal wear particles...not a good sign. As noted above, a lab analysis of the fluid can be $30 very well spent.

 

How far should I drive before I get the tranny flushed again to get a fluid sample? 1000 miles or more?

 

If you are doing it properly and using Blackstone Lab then contact them and ask their recommendation?
I dont think anyone can answer that quest not even me because unless we saw the fist analysis there is nothing to suggest when to have have it checked again based on what that analysis results were.

 

Based on a previous post, is anyone seeing dark brown fluid upon flushing the tranny? I have very dark brown fluid coming out at 77000 and 84000 miles. No mention of it at 44000 miles. Otherwise, tranny runs fine, like new! I've sent fluid in for lab analysis to Blackstone Labs. Hope they can tell me cause, and not just metals in fluid. I'm guessing tranny is overheating, but don't know why as yet.

 

I ended up driving 7000 miles or little less than year. Fluid dark again, so sample sent to Blackstone.

 

This will be good helpful information!

 

92k on my 2014 Cx9 Trans , if trans fluid dark or burnt should I still have it serviced ? Was told it would do more damage if fluid was bad >Shifts weird at times, How does the dip stick come out tried pulling on it but seems like it stuck, what's the trick?

 

just got lab results back. No evidence of overheating. Properties like viscosity good. 3 metals were higher than average values. Aluminum. Tin. Copper. I just found out that my trans shop didn’t or couldn’t drain all of the fluid. Unclear on how much left behind. Will have to call back to clarify. The lab recommended flushing again after about 7000 miles.

 

A filter service only nothing more. This way you can see what is in the pan.

 

Transmission service gets a bad reputation. People wait until the transmission is having problems and expect a flush to cure the ills. It can't. The transmission then continues to failure and the flush gets blamed. If one is leery of a flush, do get the pan drained, cleaned, internal filter renewed, and new fluid added to the sump. The majority of the fluid remains in the torque converter, so you'll have maybe 1/3rd new fluid. Another couple of drains and refills after some driving, and the fluid will be in decent condition.