Oil leak

[david75]

2.5 V6 Auto
I was changing the oil today and while I had the undertray off I saw what appeared to be a bit of oil along the join between the two casings marked in yellow on the picture.

The picture is looking upwards under the car just behind the front bumper. The silver coloured casting is the auto box, and I am not sure what the black casing is. The join between the two appears to have some kind of black sealant visible.

When I wiped the oil off (the picture is just after I had cleaned it) it appeared to be the colour of engine oil (brown). (I may be wrong about that, but I would have expected auto trans fluid to be more red, and this was changed less than 5000 miles ago). Having said that, I had not noticed the engine oil level changing since the last oil change. I couldn't really tell whether there had been a consistent leak because the upper (inner) surface of the undertray is quite grimy anyway,

I put a socket on each of the 10mm bolts that you can see outlined in yellow and they each fairly easily tightened about a quarter turn. (I have no idea what the torque setting should be).

After the oil change I ran the car for a few minutes and the leak seemed not to be happening.

Not being familiar with what the black casing is (my mechanical abilities do not extend much beyond simple things like oil changes), I don't really know what I might have just fixed, or indeed might not have fixed.

Any observations or advice?