How about if I Drain all I can and replace that much new fluid with new filter.. Drive it awile and drain and fill again maybe 3 or 4 times.

This is what a lot of people do with the later model cars. I recommend draining into a scaled/marked receptacle with markings in 1/4 liter intervals. Replenish EXACTLY what you drain.

At the dealer they use a machine that connects to the transmission cooler lines at the radiator. It extracts the old fluid while it pumps in fresh fluid. They also interface one of the car's computers with something called an SDS(?) and it reads the internal transmission temperature. The target is like 80C. Then using a dipstick that is not provided with the car, they measure the level at 80C to ensure it is filled to the right level.

Some DIYers with the 722.6 (5 speed) just drain what is in the pan and replace what comes out, occasionally replacing the filter. Some take it a step further and use an IR temp gun to see if the center of the pan is at 80C and then use a purchased dip stick to measure.

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2006 BMW M5 "Heidi" @ 109,000 miles
2005 MBZ C55 AMG "Lorelai" @ 165,000 miles
1991 MBZ 300E "Benzachino II" @ 165,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles

(On the hunt for a good used M103 engine as of 6/10/23, PM me if you have one to sell!)

STOP!!! Let the dealer do it!!! Like I said in my previous post, trust me!!!


What you don't realize is that there's a filling tube attached to the inside of the transmission pan that extends about 1-1/2 inches up. That's why you're not getting much fluid when you remove the drain plug!!! If you unbolt the pan you're gonna' make a mess, and you won't know how much fluid to put back in!!! Also, there's NO DIPSTICK TUBE on a 722.9!!! You have to pump the new fluid in through the drain plug hole!!! I admire the determination of all the DIY'ers on this Forum, but you're asking for a huge headache if you proceed without understanding what's involved in servicing the 722.9.

ILUVMILS is completely correct. What I said previously is what some people do with the 722.6 transmission, the 722.9 is a completely different beast and must be dealership serviced.

__________________
2006 BMW M5 "Heidi" @ 109,000 miles
2005 MBZ C55 AMG "Lorelai" @ 165,000 miles
1991 MBZ 300E "Benzachino II" @ 165,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles

(On the hunt for a good used M103 engine as of 6/10/23, PM me if you have one to sell!)