Gentle Warning - Service your 722.9 Transmission every 39K miles 60K Km's
I am glad that I have read about the transmission fluid change thread. I have 2009 C300 4Matic with 63,000Km. I am Toronto, Canada. I called up the MB corporate office and booked a service appointment. After reading these treads, I talked to the service adviser and he said there is no need to drain the TC. He also said that they don't fully drain the transmission...and confirmed they use about 5L of the fluid. This means that the new fluid is just being mixed with the old one and the TC is not drained. I have read somewhere that if the tranny and TC is fully drained, we will need 9L fluid in total.
Now what should I do? I am planning to keep the car for long time and don't want to avoid any critical services. On the other hand, the MB dealerships are saying they don't do what you guys have specified in the DIY guide.
Anyone has experienced this and any solution?
Macsp
I am glad that I have read about the transmission fluid change thread. I have 2009 C300 4Matic with 63,000Km. I am Toronto, Canada. I called up the MB corporate office and booked a service appointment. After reading these treads, I talked to the service adviser and he said there is no need to drain the TC. He also said that they don't fully drain the transmission...and confirmed they use about 5L of the fluid. This means that the new fluid is just being mixed with the old one and the TC is not drained. I have read somewhere that if the tranny and TC is fully drained, we will need 9L fluid in total.
Now what should I do? I am planning to keep the car for long time and don't want to avoid any critical services. On the other hand, the MB dealerships are saying they don't do what you guys have specified in the DIY guide.
Anyone has experienced this and any solution?
Macsp
My trans service isn't due for another 18K km but would like to make sure I get it done properly.
My question now is that how do I know if my TC has a screw? Is there anyway to tell by the VIN or any other numbers?
Macsp
My take is that the MB services may not be patient enough to find the dime sized plug, due to difficulty slowly turning the engine over while observing thru housing window.

A 2009 will definitely have.
The Best of Mercedes & AMG
A 2009 will definitely have.

The reason you got 3 litres from your TC is you drained the sump first ~ Yes? You get some run back from the TC.
Fluid is continuously circulated through the TC to keep it cool. If the temp sensor in the TCU in the valve body/conductor plate detects temperatures rising over preset normal it immediately shunts more fluid via the TC & the transmission cooler to correct this.
If temperature continues to rise above normal it will cause the transmission to select a lower gear & increase engine speed to further increase flow through the cooler.
If this fails to get the transmission temperature under control the TCU will place the car in limp mode to protect the transmission.

Not draining the converter creates an approx 50/50% mix of oxidised fluid together with new fluid. The oxidised fluid catalyses oxidation in the new fluid. Like putting crap in ice cream.
Draining the entire system including TC is the correct thing to do.
Us MB drivers of 2012+ W204's (and other models) have the 7G Tronic PLUS. With or without stop/start systems. No one anywhere knows the fluid capacities of transmission and TC, and no one knows the process to follow at 70k miles for fluid renewal. We do know the fluid type....so that's something.
At this point, despite the 7G Tronic PLUS's apparent enhancements, I'd feel better with the tried and true 7G Tronic since it is a known item. I don't like being the beta tester. Time will tell if the new 70k change interval drops down to 39k miles again....hopefully I know BEFORE the warranty ends.
I was hoping someone here a bit more savvy can put into words specifically what I should be asking for.


Us MB drivers of 2012+ W204's (and other models) have the 7G Tronic PLUS. With or without stop/start systems. No one anywhere knows the fluid capacities of transmission and TC, and no one knows the process to follow at 70k miles for fluid renewal. We do know the fluid type....so that's something.
At this point, despite the 7G Tronic PLUS's apparent enhancements, I'd feel better with the tried and true 7G Tronic since it is a known item. I don't like being the beta tester. Time will tell if the new 70k change interval drops down to 39k miles again....hopefully I know BEFORE the warranty ends.
http://www.sussexautos.co.uk/images/...es/Binder1.pdf
for fluid and design. Likely similar capacity as 7G -- just measure how much comes out then do +1 qt, warm to temp and adjust fluid level. That's my suggestion only. Do at your own risk -- I am not a mechanic.
Ask the dealer for the WIS on this transmission and fluid designation/part number.
If you have US address on credit card, get the one year free access to EPCnet Online at http://epc.startekinfo.com
You can see if there's a TC drain plug and get the part number for the bolts, gasket, filter, tranny pan drain plug seal, wier tube, TC seal with plug, fluid, etc. Beware that sometime the manual does have mistakes. Make sure the color of the ATF matches. ATF 134 (red) vs ATF 134FE (blue). At 70 kmile it will likely hard to tell without putting on white rag or paper. I would do it well before the warranty expires -- just incase something goes wrong after the service.


My question now is that how do I know if my TC has a screw? Is there anyway to tell by the VIN or any other numbers?
Macsp
The TC can be rotated and examined for the screw/bolt. There was a time where no TC drain was present on certain model and then it was put back in. Lots of places are just too lazy to do it. Or can possible be justified as don't like running the tranny dry during the initial refill, which does make sense. I don't know what is worse -- not draining or draining and having a few seconds of not having fluid. It's like too frequent oil changes damaging a car. I have heard that there is lots of crude in the TC from the initial friction packs.
Last edited by dave2001auto; Sep 18, 2013 at 09:22 PM.

The Workshop Information System is the Benz Bible that all dealers are supposed to operate from.
https://mbworld.org/forums/c-class-w...ce-thread.html

The Workshop Information System is the Benz Bible that all dealers are supposed to operate from.
https://mbworld.org/forums/c-class-w...ce-thread.html



The Workshop Information System is the Benz Bible that all dealers are supposed to operate from.
https://mbworld.org/forums/c-class-w...ce-thread.html




