Hello Everyone,
Since there isn’t any information about doing your own transmission fluid change on the M177 biturbo models I have decided to make a thread. The 722.9 7g transmission has been around since 2004 with an upgrade to the Tronic plus 7 speed transmission has been around since 2010.It can be found in many applications from a simple c300 to all AMG models. I’m not going to go into further detail being that the information is out there on google.
So to the point. I was recently quoted $904 for a trans fluid change at Mercedes here in southern Cali. I talked to a buddy who works in servicing at that dealership and he told me just to bring it in. With his discount and California’s high tax I paid a total of $210 for the parts. He threw the car up on the rack and changed the fluid right in front of me. Just like I predicted the job is done the same way as every 722.9 transmission out there.
Remove drain plug and let it drain.
Knock over overflow fitting and let it drain.
Remove all pan bolts.
Remove pan and drain.
Remove and replace filter.
Clean pan and magnets
Replace pan gasket
Replace overflow fitting.
Install pan
Service tranny with new fluid.
Done.
Nothing else is required. Confirmed by a master mechanic.
Obviously there is more to this DIY like how to properly service the trans with fluid, but there are tons of YouTube videos on how to do it. You will also need the right fitting and a fluid pump. Just type in mercedes 722.9 fluid change.
I’m not a master mechanic. This is just information I’m sharing with everyone so for all the people who want to troll my thread, you can save it. Just because you did an oil change once doesn’t make you a know it all.
I am also not responsible for what you decide to do with this information.

222-277-20-00 Trans Filter
007603-012102 Plug Washer
220-271-03-80 Pan Gasket
222-271-00-97 Overflow Pipe
004-990-35-12. (6) Pan Screws
000-989-69-05-11-AU750 (6) Tranny Fluid

722.9 MCT:
The pan bolts are 1 time use, 4nm + 180 degree turn, which i am only able to get 90 deg turn in. Sounds like you got it all down correct.

The fluid needs to be pumped in, filled and than checked while running, shift car into P,R,N,D 3-4 times, 5-6 seconds between each change, than check oil level for slow dripping at EXACTLY 45C, if no drips, it is underfilled, if a strong stream, overfilled and wait until it drips.

over 45C and the trans will be underfilled as it will released too much fluid, if you check it below 45C, it will be overfilled.

About how much Fluid should the car take? And the wet clutch can't be drained correct?

Correct, wet clutch cannot be drained.

I like to put anywhere from 6-8L, during the level check at the specific temp using either icarsoft scanner or Benz Xentry, the extra oil that the trans doesnt need will exit out regardless when checking the level at this temp.

Good job leatherneck!
And thanks for your service!

so if the torque convertor (wet clutch) is not serviceable, then does it have no drain plug or is it just that Mercedes just doesn't require it to be drained during a trans service? did your mechanic friend mention anything about needing to also flush the old fluid from the trans oil cooler? How much trans fluid went back into your car?

Hi sir, I have a question hoping you guys can help me out. I just did an transmission oil change, and i realized some weird thing happened to my transmission. when I shift from P to D, the engine RPM at idle rise about 500 rpm, and when i shift from D to R, the engine RPM rise also and my car just surge forward and i can feel the gear change very obvious, this never happed before i change my transmission fluid. what may cause this, did i overfill the fluid or underfill. thanks,

here is a video i took

You Tube

You Tube

I believe this is normal when changing into gear because you are now ‘loading’ the transmission and so the RPM will change accordingly. When I have some time I can double check if my vehicle does the same.