DIY transmission fluid change/flush


I'm going to be changing my transmission fluid soon and I figured I'll post a DIY on doing it. You do need some special tools like a fluid dispenser and a special fitting made by Assenmacher but not impossible to order. Also it is said that you need Xentry/SDS to read the temp of the fluid but on my last change I was able to verify that an infrared thermometer was pretty close to within 1 degree.
Other than that its pretty typical. What I am also going to do is after dropping the pan, I will overfill the tranny by 1l and disconnect the feed hose by the radiator and bleed out 2l and then replace 2l back again until everything is out. I did a change last time and the fluid was a brownish red so it wasnt too bad but replacing just half of the fluid with new didnt sit too well with me. I'll be posting a DIY later this week
Last edited by Nickthegreek; Jun 9, 2015 at 07:58 AM.


Tools/materials neeeded:
Tools
8mm socket
E12 torx socket
6mm hex socket
Ratchet and various extensions
Mityvac ATF adapter kit (comes with the mercedes 722.9 adapter)
9l drain pan
transmission drain pan
Some type of fluid dispenser (I use a pneumatic spray paint container I bought from harbor freight. I had the mityvac but it is just very slow and leaks bad. In the end more fluid would be on the ground than in the car and it also exploded on me when I pumped it alittle too much alittle too fast lmao.)
Car Jack
Jack Stands
Screwdriver
Level
about 3-5 feet of 3/8 transmission line hosing
Torque wrench that measures in in-lbs
Mercedes Star Diagnosis or a infrared thermometer
Materials
Mercedes filter
Mercedes transmission fluid ***make sure you know if you need the blue vs the red for your year***
mercedes pan gasket
mercedes pan bolts
mercedes fill pipe
I wouldnt skimp and get aftermarket parts. Get the OEM stuff
Last edited by Nickthegreek; Jun 8, 2015 at 03:42 PM.


Ok so first jack the car up on 4 jackstands. They have to all be identical because the car must be level. I have 4 jackstands that I modified to fit my car. You may have to do the same or buy specially made ones for mercedes online. If you want to check if the car is level. check both lengthwise and width wise to see if the car is level. Otherwise try to shimmy the car. Next there is a boatload of 8mm bolts holding the under belly panels. remove these. I would suggest using an electric driver.
Next setup a transmission drip pan and a drain pan.
Now you will have to locate the drain plug and use a #6 hex socket and bust it open. This part is just like doing an oil change. The fluid will come out, but it wont even be close to all of it.
That large circle is an external magnet I put on my pan.


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Each bolt goes through what is called a sprag. The bolts MUST not be reused and must be discarded. the sprags can be reused.
Last edited by Nickthegreek; Jun 8, 2015 at 11:14 PM.
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passenger side bracket attachment. bolt is removed
the transmission pam bolt is hidden under the bracket
Remove this wire from the clip and then the bracket will come off
Last edited by Nickthegreek; Jun 8, 2015 at 11:15 PM.




Last edited by Nickthegreek; Jun 8, 2015 at 11:17 PM.


the filter fell into the pan while I got it out. The white thing is the standoff tube. There is still a considerable amount of fluid in the pan. luckily little to no clutch material but I also have done a pan drop on this. I put neodynium magnets into it after as an added insurance






Standoff tube installed
Last edited by Nickthegreek; Jun 8, 2015 at 11:19 PM.


Now install the new transmission filter
Push and wiggle it in and it will snap in. It isnt all that tight but when the pan gets put on it will support it. I then sprayed the sealing surface with brakleen to get rid of any oily residue
Last edited by Nickthegreek; Jun 8, 2015 at 11:21 PM.




The sprag is to the left. It hooks onto the flange of the pan. Make sure the hook grabs it correctly











Make sure to post lots of pictures if you can.