What are these 2 rectangular rubber covers?
 

I was under my truck tonight and saw 2 rectangular rubber covers in front of the tranny pan. They are about 1’’ by 2 ‘’ with a small hole in the middle. I pulled one cover off and saw a part number A163 271 0080. They cover a housing between the engine and the transmission. I peeked into the opening and saw a big gear; I guess that’s the starter plate?

The question is that I got a big oily path around the rectangular openings; It doesn’t look like a leak, since the openings are not sealed and inside is completely dry. It more looks like some sort of oil vapor accumulated there with dirt.

Any insights? Should I seal these 2 holes with masking tape :D

roque converter drain plugs

Thanks! I just read the diy artical on changing tranny fluid and it is the housing for torque conventer. I can see the the fly wheel from the opening. So does the oil path mean I have a tranny leak? The inside of the housing is really dry though.

Transmission Fluid
 

The transmission cooling lines on the ML have been known to leak. The "sealed for life" transmission is sort of ridiculous if the hoses leak, wouldn't you agree?

Well, I have to say it is sealed for the life of warranty, after that, you are on your own, LOL.

Since I have this possible tranny leak and I am planning on changing the fluid in a bout 10K miles. I am thinking to buy a dip stick to check out the level first. Do I need to buy a replacement cover? Since the existing cap looks like an one-time use, break-away type.

Transmission filler cap "lock"
 

Yes you will need NEW locks....they are pretty small and typically less than $1.

Get 2 while you're at it since you will want to check the fluid level again since it is so critical on this transmission.

Now after looking at again, I think it is the tranny cooler link is leaking. How do I when it? I mean do I need to remove the fitting and put in a new washer or something else needs to be done?

I think by removing the cooling line, I have to replace all the tranny fluid as well ?