[jivenene]

Thanks for all the great info guy and gals. My car is a 2006 w 98k mi on it so the fluid def needed replacement. The old fluid was a dark cherry , almost black color, well overdue.
I just tackled this job, it took 6 hrs because I dropped the mechatronic and replaced plastic sleeves and parts. It was pretty simple, just be sure to follow torque specs when putting everything back together.

I wanted to flush the torque converter out so I disconnected the top rigid line into the Transmission that was coming back from the oil cooler. I then added four quarts of new fluid (Mercon SP) into the new pan and then my friend started the car and I watched black fluid come out for about 2-3 seconds only. It splattered against the trans housing and made a nice mess, so be ready for that lol. Didn’t seem like a lot came out (I thought the TC had 2-3 L in it?) but I buttoned everything up and started filling with the motor on and got a total of 8 L in Before it started pouring back out. I monitored the temperature it was 43C. I thought I was going to get nine L back in but I think my car was not level in the back and was lower than the front. Anyway I will check it soon after driving around and making sure it would get circulated throughout the internals of the trans and mechatronic by going through the gears in M mode. Will report back in a couple weeks.

So far it runs really well and the shifts are ultra smooth. Definitely invest in a fluid pump, I got the one from Firstinfo tools on Amazon. As for BMW, any company that labels any fluid as lifetime , should be criminal. Obviously they do it for low maintenance for them while under maintenance contract , but it should be illegal to call anything lifetime lol.