300SDL transmission fluid, what type
 

Hi all;

about to change out the tranny fluid. After searching here it appears that dexron III/Mercon is ok to use in this tranny. My question is this. I have 6 liters of MB auto tranny fluid, not the 7 or so that a complete fluid change requires. Am I going to screw anything up by topping off the MB ATF with about a liter or dexron III/Mercon?

JUst did the fluid and filtr kit change on my 300D.
Fun but messy job...
You are fine adding the last .6 or so litre with non MB fluid.
(That's what you meant right?)
Just be careful to not add too much would check/ recheck on fllat surface after a 20 min. drive....then if needed add a little at a time.
Since you're adding 6 qts you are draining the torque converter too??

Yep, I figured that as long as I was going to do it I might as well drain the TC too and change the filter and replace the gasket. I'll try and find a big catch basin to avoid the mess. Thanks for the warning.

No problem mixing brands. Check the specs again. When I replaced the fluid in my SDL I'm pretty sure it took more than 6-7 quarts.

Sixto

specs are 7.1L I'm pretty sure. No prob on the fluid I've got the 6L of MB and about 6 Qts. of dexronIII/mercon laying around the garage. I'll double check the specs again though, just to be safe.

I'll second the point about being very careful when you approach the lower mark. It takes about 8 oz. of oil to overfill it when you are close to the bottom mark.:o

So I'm assuming that about 6.5L will get me in the ballpark. Then drive for a while and check the level again when its hot?

You're certainly up late tonight...

Definitely stay on the low side and see how it is when hot. Then, be extra careful topping it off..........less is better.........

Yep..........just back from a little "meeting".........LOL.

Thanks for the advice, Brian. Well, it's late for me, so I'm off to bed and at the tranny in the am.

Good luck with it Matt. Whatever you do........don't overfill it.;)

I checked mine a few weeks ago (after going 6 months without doing so) before a long trip, and it was about 1cm below the minimum notch on the stick, and I had to add about 80% of a quart to get it to the full notch, so that was about 27oz.....I use synthetic (Mobil 1) and it runs sooo nicely. :D I hadn't checked it since Mid october when I did the switchover. After I added the fluid it ran even smoother, and has been great ever since.

The issue with the overfill is common on the SDL. If you added 27 oz. to the SDL it would be about 3/4" above the high mark.:eek:

When checking the tranmission fluid level, should the engine be running and the transmission in park ?

Yes. And on level ground too....it should also be at operating temperature.

As Brian said it doesn't take much to overfill these trans. Since mine has a leak I made the mistake of adding about 1/2 a quart when it was at the 1/4 mark. Just a little overfilled!:eek:

Anyway make sure that MB fluid is compatible with the older trans. It isn't that new stuff that all the sealed for life trans use? I don't know if that stuff is backwards compatible.

I think I added 6.5 quarts total last time I changed it.