Simonas.st

Hello,
I've been having leaking transmission, where it meets engine, for I think two years now. I've been solving this problem, by adding fluid, every time, I felt it needs it. Usually every 4 months. I've been doing so, because I was afraid of pulling the gearbox to change the gasket/seal, or whatever is causing the leak. Now I feel, that time is coming, when I have to deal with this issue more seriously. At first, I'm interested, isn't there any sensor, that should tell that transmission is low on oil? Another thing, have anyone tried to pull transmission without dealership involved? I'm quite handy man, and have some trust issues with workshops. I also think, that it's 230000km, maybe it would be time to disassemble transmission and change all seals/gaskets, and whatever needed to run again for 250000km or more, since, I have no plans to sell that car ever.
Thanks.

alx

there is no level sensor and if you run dry you will not be notified that oil is low. other bad things will happen, but no error message specifically for low (or overfilled) oil.

adding blindly oil may overfill or starve tranny for oil- both equally bad.

oil level is checked manually by removing the drain plug and observing a dripping of fluid at specific tranny fluid temperature. if nothing comes out - oil is low. if oil comes down in a steady stream- it is overfilled.

it is most likely your tranny input shaft seal. they do go bad and are fairly easy to replace if you remove transmission.

Simonas.st

When I'm filling the oil, I'm doing it in MB shop. They filling it with for e.g. 2 liters, when car is running, disconnecting the pipe and let the oil flow until it stops. I've trusted this, since, no new issues noticed, after doing that for about 2 years.
Yesterday I called workshop, which is working only with automatic transmissions. They told me, that it's very unlikely to be seal,because it rarely happens in MB. They told, that it could be oil pump. Doesn't sound right to me, as I understand pump is inside transmission.
Anyway they've quoted 200Eur to take out and bring back transmission, and 1.5 day. So I'm now wondering, that maybe it's worth trying? Maybe they'll see something more, than I would myself.

Note: I don't know if that could add something to the case, but like 3 years ago, engine was removed to change balancer. Maybe while removing engine, they could damage the seal?

ItalianJoe1

The seals do leak, it's not super common but it does happen. The front pump is inside the transmission bell housing, right where the torque converter goes in. So it's got a seal that keeps fluid from leaking out.

It's possible they damaged it when removing the transmission if the engine was pulled, but it's also just possible it leaks from age/wear with 200k+ KM on it.