Hi, everyone. New here. My wife got a used 1999 I30 not long ago with 131k on it. When I checked the ATF recently it looked brown. It is not darker than the dark red ATF, which I drained from other Nissan with ~60k on the ATF, but that I30 ATF doesn't have much/any red color left in it.

I do not have any per-history for the AT services so I decided to run UOA
The result shows extremely high metal content.

AT shifts just fine. Do you think I should drain&refill it several times in this situation? Maybe install an external filter also?

Here is the comment from the lab itself:

"There's a lot of metal in this sample. Aluminum can show oil pump or torque converter wear, and iron,
copper, lead, and tin come from the clutch plates. Is there any chance this is factory oil? That, plus accumulation over
131,000 miles might account for all of this metal. Silicon may be from sealers, and the low viscosity shows that the oil
run was probably a little too long. Averages are based on just 30,000 miles on the oil. If the transmission shifts well,
we'd change this oil out and just check back in 30,000 miles to monitor for improvements"

 

Changing the fluid now can be risky. But as long as it looks ok, it could be worth it. When I had my auto Maxima, I changed the transmission fluid at 231k miles, and it did fine. Not sure if it had ever been done before or not. If you do change it, put Lucas oil in it along with the transmission fluid. Just account for the added amount for the Lucas and don't over fill. I believe the transmission holds a little over 4 without a filter change, and more with it. It should say in the manual.

 

If it works fine, do a drain, remove and clean oil pan with shavings on magnets, reseal and fill and then drain and fill a second time a week later.

 

pull pan and have a look... my fluid was dark, not red more brown ,and tranny went out a couple months after buying car... pulled pan on old tranny when i swapped it out and there was so much metal on it looked like i had exhaust donuts in my pan... check ur pan that's the best way

 

Lab gave you the reason and the action you should take.
These transmissions can hit 300,000 miles if cared for. There built well.