Hello, How can i know if my transmission oil is low on c-class W204??

 

By taking it to a dealer. There is no other way to check as it requires one of their tools.

 

Unless it is leaking, it cannot be low. (It can actually be filled with the wrong amount of oil in the first place by an incompetent mechanic)

 

Only way would be to lift the car up, get the transmission oil to 37 degree C and pull the drain plug. If you see it splutter then it is at the correct level, if you don't see any fluid coming out then it is underfilled, and if you see a solid stream coming out and is not sputtering right away then is overfilled.

 

Along with temperature car must be perfectly level.

 

I would assume with all the electronics in that box, you should get a low level warning in advance and then visit the dealer.

 

Get a $4 cap to the trans dip stick pipe, get a 17 dollar dip stick for that 722.6 or 722.9 box from Hong Kong. Break the cap, see YouTube, before heat oil to 80 deg. Celsius, use dip stick to measure level at 80 degree Mark. Oil should be changed every 60000 km, see user guide. Lift car, take 2 panels off, check for leaks is another method. Use hoist with friend as engine panel is heavy

 

I don't think there is a hole in the transmission body to attach a dip stick tube on 722.9. I hope I'm wrong because it would be nice to have a dip stick.

 

Have a look at the back for a red cap reading: "MB only" right at the firewall. That is the dip stick pipe. You have to buy the dip stick from Hong Kong for less than AUS$20, Merc sells the identical for AUS$70! The filling of the oil is temp. related and the dealers must have a dip stick as the level is critical. You also have to buy that red cap as you break the top off to open the pipe up for refilling. MB said at one stage "Sealed for life" and the official speci for the 324.16 oil repeats that, after problems with auto failures regular oil changes were introduced. On my C220 CDI W204 2007 build it is 60,000km according to the service booklet.

I have not come across a low-level warning, but someone put in a GLK-xx model number (not his!) and his MB2 diagnostic gave him the oil temperature, which is critical. The dip stick shows two ranges, one for 25 and one for 80 degrees for the oil. I bought a hand-held laser thermometer and shone it into deep into the dip stick tube and got 77 deg. as the highest reading.

Warning: DIY auto. oil changes are only partial, as some Mercs may not allow you to flush the torque converter. So what a DIY person has to do is buy up to 15litres of Merc, Fuchs, Shell, Mobil, etc. equivalent, drain/hand pump 3.5 litres out and no more out of a total of about seven litres, refill, run, drain, etc. until the oil looks more and more reddish and no longer grey/black. Also drop/clean the pan and magnet and install a new filter plus pan gasket. I also changed the pilot bushing, which holds the electric connector as the two O-rings start leaking with age. Oil then is wicked into the critical electronics leading to failure. The pilot bushing is only about AUS$15.

Dealers are supposed to use a flushing machine. Become a Youtube mechanic and save! We only ever use the best fencing wire for our repairs!

 

The pulling of the drain plug and then seeing what is happening is possible with models with an overflow pipe, but I am ignorant there which ones are. I have only worked on my 722.6 gear box.