Transmission fluid change

[platt-deutsch]

Is there a plug on the Torque Converter so I can drain it ? 2007 W221 7 speed.

[BAD300]

Drain tranny fluid from torque converter? Sure you don't mean the trans sump tray? If so, I don't think you can when it's fitted to car. You normally have to drop the sump tray to drain all fluid. Only other way is to try & get most out using a trans siphon/hose & fill it back that way. Doubt you'll get all the oil out that way though

[platt-deutsch]

Well, Seems there is not much of the fluid in the transmission pan and most of it is in the Torque Converter so that is why I am wondering if there is a drain on the TC.

[lkchris]

Nope.

[ILUVMILS]

Be careful!!! The 722.9 transmission requires special equipment to re-fill properly. If you've already removed the drain plug in the pan, put it back!!! Don't mess with it!!! Trust me.

[platt-deutsch]

How about if I Drain all I can and replace that much new fluid with new filter.. Drive it awile and drain and fill again maybe 3 or 4 times.

[Rahulio1989300E]

Originally Posted by platt-deutsch

How about if I Drain all I can and replace that much new fluid with new filter.. Drive it awile and drain and fill again maybe 3 or 4 times.

This is what a lot of people do with the later model cars. I recommend draining into a scaled/marked receptacle with markings in 1/4 liter intervals. Replenish EXACTLY what you drain.

At the dealer they use a machine that connects to the transmission cooler lines at the radiator. It extracts the old fluid while it pumps in fresh fluid. They also interface one of the car's computers with something called an SDS(?) and it reads the internal transmission temperature. The target is like 80C. Then using a dipstick that is not provided with the car, they measure the level at 80C to ensure it is filled to the right level.

Some DIYers with the 722.6 (5 speed) just drain what is in the pan and replace what comes out, occasionally replacing the filter. Some take it a step further and use an IR temp gun to see if the center of the pan is at 80C and then use a purchased dip stick to measure.

[platt-deutsch]

Great.. that is what I will do then. I will probly use more fluid doing it this way but taking it to the dealer probly not inexpensive either..
Does the new Fluid have to be MB or are there fluids that are MB approved?

[ILUVMILS]

STOP!!! Let the dealer do it!!! Like I said in my previous post, trust me!!!


What you don't realize is that there's a filling tube attached to the inside of the transmission pan that extends about 1-1/2 inches up. That's why you're not getting much fluid when you remove the drain plug!!! If you unbolt the pan you're gonna' make a mess, and you won't know how much fluid to put back in!!! Also, there's NO DIPSTICK TUBE on a 722.9!!! You have to pump the new fluid in through the drain plug hole!!! I admire the determination of all the DIY'ers on this Forum, but you're asking for a huge headache if you proceed without understanding what's involved in servicing the 722.9.

[platt-deutsch]

hmm.. Didnt know all that was gonna come into play.. Now I am thinking it over..

[Gilly]

Why do you want to change it already anyways?

[ILUVMILS]

Hey Gilly, how's it goin'? MB recommends that the 722.9 be serviced once at 39,000 miles. I guess after that it's sealed for life.

[mbdoc]

Starting in 2008 on some models & in 2009 in all models MB NOW reccomends an every 40K service for that same trans!

[Gilly]

WHAT! Sealed for life didn't work!? The HORROR......

[lee polowczuk]

Still a change at 30k for 124 models???