BMW E46 325xi 330xi Transmission Fluid Change A5S 390R
Even though BMW claims that transmission fluid in BMW E46 is a life-time fill and doesn't need to be changed I highly recommend changing it by 100K miles and preferably sooner. By 100K miles the fluid is usually very dirty. This fluid change was performed on a 2002 BMW 325xi with A5S 390R transmission so the procedure will be the same on any BMW 2001-2005 325xi or 330xi. A5S 390R is a GM transmission so it uses Dexron VI fluid. Any decent brand of Dexron VI will work and you will need about 7 quarts of it. You will also need to get a transmission filter and a transmission pan gasket.
1. Start out by removing all of the under car shields. Remove the transmission drain plug and drain the fluid. Reinstall the train plug and torque it down to 18Nm.
2. Remove all of the oil pan screws and remove the pan.
3. Remove and discard the filter by evenly pulling down on it. Check and make sure no o-rings remain inside the transmission pump housing.
4. Remove and clean the oil pan and the magnet inside the oil pan.
5. Clean all of the oil pan mating surfaces.
6. Install a new filter. Be sure to check that the seal is properly seated and the filter is inserted all the way into the transmission pump housing.
7. Install a new oil pan gasket. I highly recommend using an OEM style metal pan gasket. The Meistersatz oil filter kit we sell comes with the metal OE style gasket.
8. Reinstall the new pan. Torque the bolts to 10Nm. Torque the bolts in order going all the way around the pan, not in a diagonal sequence.
9. Remove the oil fill plug.
10. Using a hand pump, pump the fluid into the transmission until it starts to spill out.
11. Start the car and pump more fluid unto the transmission until it starts to spill out. Run the transmission through the gears and let the oil warm up. Add more oil if necessary. Oil temperature should be between 30-50 degrees Celsius prior to closing the fill plug. Torque the fill plug to 18Nm and turn off the engine.