motoman

seek out and read "trans and diff fluid change" in C63 forum

macsp

Hi all,
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

spyked

Have the MB dealer or MB Corporate put in writing that they will cover any transmission or 4MATIC issues resulting from degraded fluid causing wear or damage.

macsp

Thanks. I am going to look at the manual, but does it say that the tranny and TC have to be fully flushed? If so, I can refer to the manual and challenge the MB dealership.

tmsiegle

Has anyone in Calgary had any experience with this at the dealerships here? If so, were they aware of the issue? How about independent shops?
My trans service isn't due for another 18K km but would like to make sure I get it done properly.

macsp

I went to another MB dealership this morning and talked to the SA. What he says is that if there is a "screw" on the TC, they will drain that when doing the transmission flush. If there is no screw, they only do the transmission drain. Accordingly the price for this service differ, but when MB quotes originally it does include TC drain as well. The price gets adjusted (lower) when the car is serviced without the TC drain.

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

motoman

mac, There is a sticky on the transmission . I believe the author stated "all" 7 speeds have the TC drain pug. If you read the C63 diy "trans and diff fluid change" there is discussion about the plug.

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.

Glyn M Ruck

Only very early 722.9 transmissions had no TC drain. They were mainly fitted to the S Class. I think we have found 2 W204's without plugs on this forum & one was doubtful. Even the final W203's with 722.9 already had drain plugs. Johnand's car on which his fine DIY service thread is based is an example.

A 2009 will definitely have.

macsp

Thanks! My service appointment is in couple of weeks...will call or see the SA again to confirm they do drain TC. I will update this thread on what happens to my service!

macsp

Motoman, you are right, these MB dealership may not be patient enough to deal with TC drain!

spyked

Just to confirm....IF they train the TC as well, they plug that up after it's drained and then fill the transmission that same way. So, somehow, the TC gets filled up via the process when they fill the transmission. There's no way the transmission could appear to be full when in fact the TC isn't full (if the unit hasn't been driven for example, getting fluid circulated through entire system). Right?

motoman

spyked Read the Sticky. It calls for running the trans to temp and letting the excess fluid out via drain tube. If insufficient fluid has been added there will be no excess fluid out the drain tube and a sure warning sign. There is no dipstick to measure. No one has answered my question put in the diy about circulation back into the trans sump of TC fluid, but it is implied. As noted the diy showed more heavily discolored fluid from the TC. Does the rotation hold the swarf in the TC? Don't know. Three liters of fluid came out of my C63 TC.

Glyn M Ruck

The TC generally holds 4 litres, nearly half the fluid charge. Fluid is continuously circulated through the TC by the transmission pump. The minute you run the engine the TC is filled from the tranny sump & further top up is required.

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.

motoman

Good and clear. Should help all, but is their a significant amount of "dark matter" retained in the TC , not circulated back to the filter?

Glyn M Ruck

The TC fluid would typically be in the same condition as the pan fluid although some centrifuging may take place.

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.

mmike

anyone know a dealer in los angeles that knows about this?

spyked

At least you guys have a process and can take your dealer to task if they don't do it. You can tell them what needs to get done.

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.

bcdiamond

I'm a bit lost in knowing the deal with this. I've been contacting several service providers here to see who will actually drain the TC (as this is what I thought needed to be done). I got the following email back saying, "There is no torque convertor drain. We remove the oil pan and drain as much as possible. Change filter and gasket and then refill."

I was hoping someone here a bit more savvy can put into words specifically what I should be asking for.

dave2001auto

Check out
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.

dave2001auto

See my post the free subscription (above).
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.

Glyn M Ruck

These dealers are damn useless. Print out the WIS instruction on draining the TC & the pan from this thread's long list of provided pdf's or the Wiki & stick it under the dealer's nose as others have done.

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

Glyn M Ruck

Also for info:

https://mbworld.org/forums/c-class-w...ission+service

bcdiamond

Thanks Glyn, that's what I was thinking. The sad part is I showed this to the dealer initially and they still told me that most of the cars they have come in do not have the screw to remove. This lead me to go to the person referenced in my initial post who told me what I posted and also listed he was an MB tech for 8 years. I'm skepitical to take it to a shop that tells me this (even after providing them with the WIS) as I have a feeling they won't do the job right and I won't be able to tell.

Glyn M Ruck

The fact that you have a 2010 car & they are still talking nonsense does not engender confidence in them. Idiots!

dave2001auto

Without a dipstick, the ATF can not be easy examined. That's makes inadequate service hidden. Even it they didn't change any of the ATF, you will not likely know. I've called a Toyota dealer on a non-existing change of the ATF based on no charge for the fluid and the ATF from the dipstick.