jenyap

Does anyone know what the lowest mark on the a.t.f. reservoir is for? It’s a little hard to see but it looks like mine sais 20c on it.

JHowell37

I think that's the cold level.

jenyap

The reason I’m asking is this- the transmission has been acting a bit “strange” for the past couple of days so I jacked the car up to check the level. When engine is off the reservoir is full to the rim, when I first start and run it through the gears it’s right at the max level. What got me worried is that once the car reaches normal operating temperature it goes above max. I do recall filling it to between the min and max level when I replaced cooler lines a while back, I wonder if I messed it up somehow…

Leon Speed

Which maximum?

jenyap

there are 3 marks on the reservour. 20c at the very bottom; MIN; MAX.

Hold On

From your description. It sounds like it may be overfilled. There are three marks on my 84S resovoir. Very bottom is max. full with trans cool. second mark is min. with trans warm. Top mark is Max. with trans hot. Of course this is with motor running in neutral, level surface.I think it is most accurate to take reading with trans cool. By cool I mean ambient temp 80ish F. When engine is off, and trans cool, and fluid drains back into resovoir, my level reads just above the upper Max mark to keep it from overflowing out of resovoir cap vent / tube

Now there, isnt that clear as mud ??

jenyap

Ok so sounds like I should drain it and fill to the very bottom line (20c) while cool, correct?

Hold On

That is where I would start. Drain some out then start fresh. Then after things are nice and HOT, check to see where level is relative to HOT Max. mark. These Mercedes trans. are very sensitive to proper fluid levels. Good luck with it. Kevin

jenyap

Would a 1986.5 benefit from dexron vi fluid? I've read that it has better charachteristics compared to dex iii but is it compatible with our transmissions?

jenyap

does nobody know?

6.0-928S

All Dexrons are compatable with each other. I use FLM with a quart of Trans-X.
Been using it in my 86.5 since 1989 & it'll still chirp the tires.

Hammer

928 at last

The 20c mark is used when you're working on the car at ambient temperature (Just did my filter/fluid). Where most of us do these things to avoid the "boiling in oil over the castle wall effect" when you miss the collection pan/tray/tank........So....if you're not fresh in off of a highway run, and the entire car is thoroughly up to temperature, ignore the Max. Mark. If it's good and warm, the minimum mark would apply.