gcalo

I may have referred to pints rather than liters but actually meant to refer to liters.

1st original fill it took nearly 5.5 - 6.0 liters

When I drained it 2nd time only 4 liters came out, and I let it drain for a while

I carefully measured the amount that came out.

When I refilled 2nd time I pumped the day lights out of the pump and after 4 liters it just would not take any more! It all just kept flowing out. I am sure it has a proper fluid level.

I really think the pan holds more than you think.

I am next drain going to hand pump out the pan to see what's in there. My guess is there is a liter to 1.5 liters.

I will fill the old pan with old fluid to see how much it does hold.

KyleB

It definitely doesn't hold 1 to 1.5L of additional fluid with the drain plug removed. There is certainly some residual fluid in the pan after draining, but it isn't nearly that much. It's enough to potentially ruin your favorite t-shirt, but that's about it. I assume you're filling the transmission with the engine running?

gcalo

Absolutely w/engine running

I will fil it w/water today and calculate the amount

turboawd

What? ?

gcalo

So I removed the drain plug and then set the old pan so that it was level. Put a level on it to verify.

Continued to fill with water until it was just about to flow out of the drain plug.

60 ounces went in = 1.875 quarts = 1.778 liters.

So indeed the pan holds nearly 2 liters of ATF.

Amazing but true.

So my 4 liters out and 4 liters in were accurate.

I will suck out the pan next drain and refill.

It is hard to see the water in the photo but there is a relection of the level.

gcalo

It's simply a use of the scientific theory.

If 5.5 liters go in and only 4.0 come out then 1.5 liters +/- are in there somewhere.

For certain the missing 1.5 liters +/- were not on my garage floor!!!

I was sure the pan held a good amount, and this test proves that theory.

So when just draining to flush w/o pan removal use some form of a pump to clean out what one can from the pan before refilling.

turboawd

doesnt the bottom of the pan sit level, and not the top? trans is at angle?

gcalo

I put the level on the bottom of tranny pan and it was level

So when I filled with water I set it up so it was level.

Even if I am slightly off there is still a sufficient reservoir of fluid in the pan.

It's made that way so the pump always pulls fluid and does not pull foam,

BimmerFan52

Did you stir the gears after you did a first fill with the engine running?

During my last drain and fill I was left scratching my head as to why I was a quart short on the refill until I reflected back on the process and remembered I had forgotten to stir the gears (move the gear shift lever through each gear, spending about 5-10 seconds in each gear) after the first part of the fill.

The next time I had the car up on jacks I stirred the gears, allowing the fluid to penetrate all areas of the transmission, and it drank up that extra quart.

gcalo

Absolutely ran through the gearing slowly and waited 5-10 minutes while engine was running to let the fluid circulate before filling.

Without a pan removal there is definitely 1.5 +/- of ATF fluid in the pan.

That is why I am going to pump out the pan next flush.

Tranny is shiffting beautifully and mileage is up.

A definite needed fluid change.

I can't believe BMW would discourage that.

Next now is to get the differential drained and refilled.