ATF change, ATF lab report, ESSO no longer recommended by BMW or GM

[John Galt]

Originally Posted by boqibama

John, I'm confused. I did drain/refill on my 02 3.0 without dropped pan and filter change, only pumped 5.0 Quarts in. What was the temp of transmission fluid when you had your done? I did it at 36 degree celsius

I did not have a tempature read on the tranny; I just waited until it felt warm, but not hot, and then topped it off.

[upallnight]

Temperature of the fluid affects the level of the fluid. I did an experiment when I had an Audi Quattro with a ZF 4HP18 trans. I filled a glass bottle with ATF that I drained from my Audi and mark the level with tape at room temp (approx 75F) Since it was winter I left the bottle outside overnight and took a reading of the temp of the ATF (28F) and noted that the fluid level had dropped by quite a bit.

The point of this story is that the trans has to be cold when you re-fill it or the final level will not be accurate, especially if the ATF fluid in the Torque Converter is at the engine operating temp.

When I do a fluid change I jack the car up the day before and drain the fluid. I let the car sit overnight and refill the next day.

[JCL]

Originally Posted by upallnight

The point of this story is that the trans has to be cold when you re-fill it or the final level will not be accurate, especially if the ATF fluid in the Torque Converter is at the engine operating temp.

When I do a fluid change I jack the car up the day before and drain the fluid. I let the car sit overnight and refill the next day.

That is not correct. The fluid has to be at a specific temperature to check the level, not cold. Otherwise you will have the wrong level. See the maintenance procedure.

[upallnight]

Originally Posted by JCL

That is not correct. The fluid has to be at a specific temperature to check the level, not cold. Otherwise you will have the wrong level. See the maintenance procedure.

There's a range that the ATF has to be I believe it between 30C to 50C, not a "specific temp" like 38C.

The point of my post is if you drove the car around and then perform the trans drain and refill, since a lot of the ATF is still in the torque converter the ATF temp is well beyond the "range" that is in the procedure. Running the car with a cold engine and trans during the fill procedure will eventually get you to that "range" that is outlined in the procedure.