The 300D holds 6.6 qts of ATF.
When you drain the pan and the torque converter you will drain almost all of that. I've heard about 6 qts. or more.
Why would you drain and refill?

I drain and fill the trans on my 94 legend (3qts every 5K) and keep the fluid fresh by the dilution method...I do this because it does not have a TC drain plug. It has worked for me 117K miles. My friend 201K miles.
On my MB I just drain the TC.

The dilution method is a very good and quick way to keep the fluid and additive package alive in the tranny. Purest dont like it but it works.

[QUOTE=Matt L.............. no harder, and I could easily get 95% of the fluid changed. I know that the convertor doesn't run dry for long, but it does run dry if you drain it..[/QUOTE]
Well, it won't be completely dry. Unless you use some type of solvent to flush the torque convertor. Personally, I can't see having to crawl underneath the car several times to drain it and a lot of unnecessary trouble. Most of the time, where the dilution method is used, the torque convertor doesn't have a drain plug.

I can't say that there is anything "wrong" with doing it that way. However, if it is a concern of yours, and you don't feel it is more work, have at it.

Not sure I'm getting this. Are you saying to drain all the old ATF, you only unplug the pan, and not the converter; Then withthe plug out and the engine running flush the old fluid out by adding new fluid????

Just a question for all who have drained the torque convertor;
How is the drain bolt properly secured?
Is there a crush washer of sort and must that be replaced?
I would think a touch of Loc-Tite Green Sealer maybe, to secure it and keep it from loosening in use?
Torque it correctly and don't worry about it?
What's the right way?

let's see if we can take something straightforward and simple and make it convoluted and complex. yeesh:rolleyes:

Not at all. Others caught what I meant above. I mean replace some of the fluid (drain, replug, refill), run it to mix, then replace some of the fluid again. Of course, continuing this gets you asymtotically closer to replacing all of the fluid.

I wouldn't consider it if I had to use MB fluid.

Well said Pete. Why do you guys think there is a drain plug on the converter in the first place? This isn't rocket science. Drain it, fill it, run it, top it off. GOT IT!! One extra little bolt!



What if I drop it and can't find it?
What if I cross thread it?
What if my car falls off of the jack stands while I'm under it?
What if my wife likes the new neighbor?
Can that sky really fall...........
:D :D

While I've only seen one failed torque converter in my life, it took the transmission with it due to all the small metal particles which were put through the fluid.

Call me paranoid, but these transmissions are expensive, and if a bit of my time and a few quarts of extremely cheap transmission fluid would help *at all*, I'll do it. That's why I would prefer not to drain the convertor.

This philosophy extends to other things, and not just by myself. You're not supposed to drain the oil cooler on a M-B either, even though it does hold a fair bit of oil.

I'm not an auto-transmission expert, not even close, so I ask the experts. One of those is a friend of mine, has a sweet blueprinted 240D ('70?), just rebuilt the auto-tranny, has run an auto-transmission business for most of his life.

I asked him, he said don't drain the torque converter. His opinion is that it rarely happens, but if the seal starts dry, it will damage the seal and require a transmission R&R. He says just the pan, do it often. Unless the fluid is seriously neglected or other transmission problems just changing the filter and what's in the pan a couple of times is all the transmission needs, so that's what I do.

They are cool transmissions, it's been a long time since I've had an automatic transmission that lets me tow or push-start a car! Love that rear pump!

- Jeff Miller
190DT

Depends on the car and transmission.

? MattL; I still think we're talking about the same thing.

Drain from the pan
Refill with some cheapo fluid
run it a bit
drain from the pan; (and this is where I would drop the pan, clean it and replace with new filter and gasket.)
and refill with better ATF; like the Castrol Dxtron III I got 6 qts of.

I asked this question to help many of us who are new to this forum.

Yes, it does matter on the car and type, definately. Many readers are new here and may have never done this service to their car before.

Since this is the diesel forum, the 5-cyl 300 turbodiesel sedans with 4sp automatic, seems to be a popular owner serviced Benz. What's correct?

So why don't you grizzled veterans, cut some of the new guys a break. Maybe one of our professional MB Techs, would like to say something about it, because there is a correct way to do this and may save someone some grief down the road. Just screwing the bolt back in ain't the right way, especially if someone has been there before. Again, depends on the car. :D

I just had the dealership change out the fluid on my 98 E300TD and all they did was drain the pan and put in a new filter. They put in 6 qts of tranny fluid. I quess I now have a blend. At first I wasn't happy about it, but after reading this thread I believe I'm fine with it. I wish it had a dipstick so I could keep an eye on it myself. What a stupid factory move that was.