Fluid level is critical in your transmission. you have a ZF transmission, so any fluid that is the equivalent to the bmw pn #83220024359 will work. I used redline D4 in my 6HP26 ( ZF's 6 speed ). I dropped the pan, changed the filter, gasket and electrical connector ( sleeve ). bolted it back up and filled the pan with the car on level ground. put the fill plug back in and started it up. I kept pumping fluid into it until it started to weep. then shifted through the gears and kept pumping more in until it started to weep again. once it was up to temp, I capped it up and then turned it off.
then I put the big guy back on the ground and did the "reset" procedure with the key in run and held the go peddle down until I could hear the stepper motors actuating for the vanos ( that means it's re-initalizing all of the stuff )
let it finish and then drove it
I changed the fluid/fliter at 100k miles and plan on doing it again at 200k
hope this helped you out!