Transmission overfill
 

I have a 1985 300SD that has been using a little transmission fluid as of late. I have been adding some in occasionally as needed, checking when hot (I thought!). Recently the transmission has been more hesitant in changing gears so I naturally checked the fluid level and it appears to now be too full. My question... is there a quick, easy method to drain or remove some of the fluid? Mind you I am no sophisticated mechanic so I need a layman's solution!

Thanks,
TM

You can suck some out through the dipstick tube but make sure whatever you insert there is very clean. A Topsider or Mitvac or even a large syringe can be used.

Or you can loosen the 5 mm hex bolt a bit on the oil pan to drain some fluid.

TM, I'd suggest removing the extra fluid ASAP.

If it is VERY overfilled, the car will "spit" some of the extra fluid out via the transmission pan seal (and make a nice mess somewhere).

Hmmm, that reminds me of an incident I had a month after a transmission service. I don't know how long it had been going on, but one day I noticed "steam" coming from under my car and realized my tranny was leaking. I took a closer look and also noticed that the transmission pan (that squarish part) had sprayed a fine mist of ATF on my undercarriage. I automatically assumed my tranny was leaking, so I took my car to another M-B shop for them to have a look. They diagnosed the "seepage" as the result of the tranny pan screws not being screwed on tightly. Other than that, they said my ATF level was fine and sent me on my merry way free of charge. But I was pissed at the shop that did my ATF service. I've stopped going to that shop; it seems like they half-ass everything they do!

Anyhow, your post started to make me think and worry a bit. Was my tranny overfilled? The second shop said NO and stated that my ATF level was fine. They tightened the screws and there has been no leaks ever since. I'm just baffled by how someone could have not tightened a screw, or if it is even possible for tranny screws to come loose after a while if they are not tightened tight enough. By the way, car runs fine, tranny shifts fine, and fluid looks clean last time I checked, which was about a week or two ago. I guess I'm just concerned about what you said and the possibility of long-term effects as a result of overfilling, if that was the case.

A transmission doesn't use fluid
 

Greetings Tony,

A transmission doesn't use fluid or goes through fluid let's say like an engine might burn off engine oil. It's either in the pan or it's leaking out of the pan or seal. In most cases if you check your tranny fluid after running it down the road twenty miles or so, operating temps, and it shows full on the dipstick after inserting it a few times to double check yourself. Look on the back of the dipstick not the front for the true level. If your level is going down, then it's sitting on your driveway after being parked there for any time. To remove the excess you can either suck it out from the top as mentioned or loosen the rear pan bolts to let a little out. Don't run it overfilled, will cause damage to the tranny if it is in continued use.

Charles

Cossie,

When my trans fluid was overfilled and it spit out, it still maintained a less, but still over-filled level following the spit-out.

Also, I believe if you overtighten the pan, you may also crush the gasket and cause a leak...

sucking it out of the dipstick tube would be best.
it is slow but safe and easy task.

i would avoid taking it out from the pan by way of
the small screw unless you will be quick enough to
remove and insert a new copper gasket. if not, the
screw will end up eating up the old gasket, hence,
messing up its thread.

this happened to me and i ended up at my local
machine shop, and several hours of labor.