w204ant

Hello I have a 2009 c300 and havent done any transmission service since the car was bought. I am current at 109k miles and its still running, it seems that its sluggish. So the question is should I flush my transmission fluid or change it? Ive heard that flushing a transmission that hasnt been changed can make it faulty and problems will occur. Any thoughts?

Plutoe

Change the fluid and filter---live long and prosper!

dennish

An indy MB tech that I trust says don't flush. Drain transmission and TC and change filter. Refill.

Colin G

Most MB dealers don't properly flush either.

superangrypenguin

MB dealers should follow the WIS. In the WIS there is no mention for a "flush", just a drain and fill

C300Matic

I don't think I ever heard a reputable source recommend a flush on any AT. Drain Fill & Swap Filter

Carsy

What would you recommend when you have no drain plug on the TC?

C300Matic

Me personally - not worry about it

If it was a car I was trying to meticulously maintain, I'd drain & fill the ATF every 30k or so.

dennish

What I do on the 2001 e430(no TC plug) is drain and refill the pan. After about 1K, I drain again. This time dropping the pan and changing the filter. Refill measuring with dipstick @ 80 C.(both times). I think this gets most of the old fluid changed.

superangrypenguin

Drain and fill a few times. NOT a flush. Those are two separate things.

Acapulco Bill

The 722.9 transmission TC should have a separate drain plug, usually have to rotate the TC for access. Should take 2L, plus the approx. 7L for the drive section. Here's the Sticky:

https://mbworld.org/forums/c-class-w...ce-thread.html

superangrypenguin

Can confirm it's around 2L. Just had mine done. Cheers!