I have a S Class W221 with 7G-Tronic gearbox. Yesterday I drained the transmission fluid, changed the filter and the joint.
I thought that this 7G gearbox had a hole to introduce a dipstick but it doesn´t have it. I have read that for the fluid level measure it is indispensable to use a especial machine that fill and measure under presure and specific temperature.
Somebody knows another way to get the correct fluid level?

Thanks in advance,

Did you look under the hood near the firewall? There should be a red cap on a tube which goes down into the transmission. Two problems. Firstly, the cap breaks off when you remove it and secondly you need to buy a MB "tool" to measure the transmission fluid level. This tool is an oversized dipstick in terms of length and graduated. MB has deliberately made it so long that you cannot close the hood with it inside the tube and there is no plastic surround to stop dirt from falling into the tube.

In other words they want you to take your S Class back to the dealerships.

Finnaly I done it. See the answers in the links:

http://www.mercedestechstore.com/pdfs/331_0405update/04-331%20pp%20722.9%20print(FH)%2002-18-04.pdf
See page 32 for filling english manual.

http://www.mercedestechstore.com/pdfs/286_722.9/286%20HO%20722.9%20062504.pdf
See page 55 for oil liters necessary.

you measure the fluid at a specific temp from an overflow tube. No dipstick.

Kar don, yes, the measure was at 45 şC without dispstick. When I saw the oil didn´t fall then it was the correct measure.

Hi m2r2, I am getting ready to do this on my friends sister's 06 C230 sport and based on everything I have read, she has a 7G/722.9 transmission as well. Car currently has 52k on it and the recommended 39k transmission drain and fill was never done.
I have been researching for a DIY for weeks now and have not come up with a single instance where someone actually performed this, besides you . I am hoping your personal experience will help me attain this drain and fill.
I already have the following parts:
Mercedes Guide tube 251 271 00 97
9 Liters of Fuch-Titan 3353
Mercedes Pan bolts (6) 004 990 35 12
Elring transmission filter
Elring Transmission pan gasket
Washer for drain
Now for the questions:
MB states that anytime transmission service is done, they should change to the updated pan and longer filler neck, did you do this?
Did you change the filter?
Did you switch to the new filler neck (white)
And the most important question, how did you pump new atf in. I have seen that Assenbacher makes an adapter for this and also sells a pump as well.

I am researching this for a week with no solid answers. I have performed this task plenty of times on other cars and recently did a DIY for E60 forums if it interests anyone. I would be happy to write a DIY for this community as well.

http://forums.5series.net/index.php?showtopic=88129

All help is greatly appreciated.

Regards.
Raj Datta

Now for the questions:

MB states that anytime transmission service is done, they should change to the updated pan and longer filler neck, did you do this?
I have a S class with the pieces updated. I didn´t have to make any change.

Did you change the filter?
Yes, it´s absolutely necessary.

Did you switch to the new filler neck (white)
I had it the new filler neck white.

And the most important question, how did you pump new atf in. I have seen that Assenbacher makes an adapter for this and also sells a pump as well.
I bought a simple manual pump that you can find at any neighborhood hardware store

Best

Hopefully, I will be just as lucky and the car will have the updated pan and filler plug. I should finally be able to inspect the car this weekend.
I will report back once done.
Thanks again.
Raj

Did my 3rd transmission fluid change on my 2007 S550 (90,000 miles) last weekend.

If you don't have a star diagnosis unit, use a IR non-contact thermometer.

I compared values on the SDS with IR non-contact thermometer pointed to oil pan and it was within 1 to 2 degrees.

Anyways you have a range to check the level of 40 to 45 degrees celsius if you have beveled pan with white fill tube. Otherwise 30 degrees celcius.

BTW, many forget to drain torque converter (4mm allen) and don't forget to replace 6 aluminum pan bolts as they stretch but I saw you purchased them. Tighten to 4NM plus 180 degrees.

Fluid I've been using since 2,500 miles is Redline D6 ATF.

Thanks Joe, I was successfully able to do the transmission fluid as well. As you suggested above, I used an IR gun, waited for pan to reach 40 degree C and then opened the fill plug. I do have the updated beveled pan and the higher fill tube.
To be 100% certain, I measured how much oil came out as well. I used Fuch Titan 3353 ATF.
Raj