I just attempted a fluid change on a 2004 with 348000. I had been having troubles with shifting from 2nd to 3rd. when the transmission tried to shift, it would go into 'neutral' before shifting. if I timed it just right I could just barely let off the pedal at the right rpms and it would shift a little smoother and I would continue driving. a few weeks ago it completely failed to go into 3rd, and I had to coast off the highway. I let it sit for a few minutes and got back home ok. I read the code, and it was incorrect gear ratio.
that's when I started digging through the transmission posts here. after hours of reading, I went ahead and bought all of my parts for a fluid change, hoping that it would solve the problems. I bought a filter, Fuchs fluid, T.c.m. connector, and gasket from Europarts along with a dipstick.
upon reading the dipstick it was definitely low. maybe about half full on the stick. I went ahead and drained, dropped the pan, dropped the valve body, and thoroughly cleaned and inspected the solenoids and sensors. much to my dismay, once I got to the torque convertor plug, I saw that whoever serviced it before had completely stripped it, so I decided to skip that for now and put everything back together and refilled with 6 liters of fluid.
now one thing I didn't do, that I wish I had, was disconnect the negative cable to the battery. when I started it up, I noticed I had 3 lights come on, the abs, wheel traction, and another yellow one next to it that I can't remember off hand. I also noticed that the shifter was stuck in park. I had to use a trick I learned from an old mechanic and stick a small screwdriver into the shifter housing to get it to disengage.
when driving, it was noticeably faster, and smoother, but the shift flare from 2 to 3rd was still there. im wondering if I didn't engage the selector valve properly, and it seems like there is too much fluid having not drained the torque convertor. im about to re drain and take a look, but any thoughts are greatly appreciated.