Transmission fluid change
 

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

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 :o

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.

Nope.

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. :eek:

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.

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?

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. :)

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

Why do you want to change it already anyways?

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. :D

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

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

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

40 K miles should have been changed. I now have 60K on it. It is shifting rough on low speed downshifts and I thought maybe a fluid change would perk it up.. Of course it could be the B1 or B3 clips have let go also.. I would think that a fluid change at 60K miles would be a good thing but it almost looks like MB has made it a difficult task.

Lee, correct 30K miles on the non-electronic transmissions.
platt-, yes they evidently didn't quite get through to people to not mess with the transmissions on Mercedes so have gone an extra step to make it harder for the masses to change tranny fluid. I swear at some point they'll require a special tool to open the hood!

That is when I go all Mad Max on Mercedes-Benz, buy all the W124s within a 20 mile radius, and clean out every site online for spare parts. :D

ILUVMILS is completely correct. What I said previously is what some people do with the 722.6 transmission, the 722.9 is a completely different beast and must be dealership serviced.

Today against advise here, I went ahead and changed the ATF in my S550. Easy! no big deal. Drained the TC,Yes there is a drain plug on it, got exactly 4 qts out of that. Removed the pan drain plug and got less than a quart. I stuck a 1/4 steel rod into the drain hole and tilted it sideways. The overflow pipe popped off and 3 more quarts drained out.
Took the pan off and cleaned it thoghly, cleaned the 2 magnets, put the plastic overflow pipe back onto the boss on the drain plug. Installed a new gasket and filter. Used 6 new pan bolts.. They are very soft bolts so dont overtighten them. Put it all back together. Took a 12 MM bolt and drilled a 3/16 hole in it. Cut it to 1/2 in long, Brazed a 1/4 in pipe coupling on it. I took the same pump I use to suck the oil out of the engine and pumped 5 qts into the tranny.. started the engine for about 5 sec. Put the rest of the fluid in a quart at a time and ran the engine for 5 sec after each quart until I had all 8 qts pumped into it. Removed my adapter and put the plug back in. 2 hrs and Done... No big deal. I notice the shifting seems much smoother now also.. The old fluid looked like Coke. No junk in the filter but was some metal fuzz on the magnets.. 60,000 miles.

The fluid gets very black due to graphite in the friction plates. Doesn't hurt anything, just looks terrible.

Maybe I just debunked another Mercedes idea.. There just aint no reason one cant change the fluid himself..

Nice job! I'm always impressed when a determined DIY'er figures out a way to get the job done. Congratulations! :beerchug:

You Macgyvered that transmission fluid change with class!
:bowrofl:

I believe I read somewhere on the WEB a year or so back that some Euro Audi's are now setup that way - driver cannot pop hood.