BLKFIN did they actually tell you what was leaking? There is no ring associated with the common socket leak, and theres no washer on the drain plug either. Strange?

The socket is like $20 online from many MB stores.

You can do it yourself but plan on more than 15 minutes since we're not perfect.

I had mine replaced a few weeks ago. They said it leaked due to an overfilled tranny. Makes sense, since I did a tranny fluid change and tried to fill the level on my own without the proper monitoring equipment. Which brings me to my next point....

The special dipstick should be used on a tranny that is at 80degrees celsius. It has markings for a cooler tranny, but its best to aim for 80 degrees since the car will tend to level off at that temp. 80C tends to be the hottest 'consistent' temp a tranny will run at after being driven a good half hour.

But you need a very expensive scan tool to get your tranny temp read. I haven't found a cheap $200 aftermarket one that will read MB tranny temps. If you don't know your tranny temp, then its impossible to read the dipstick which is made for a tranny running at 80C.

Some have said you can use a $50 infrared thermometer and shoot the tranny pan and if it says 80C then you're at 80C. Not true. The aluminum pan will heat slower than the tranny fluid and it will cool down slower also. I tried this method and its how my fluid became overfilled and how my leak was encouraged in the first place.

Some say if you drive hard for 45 minutes then immediately go park in a garage, with the engine on, then you're most likely hovering around 80C. Most likely true, but still a risk.

Sooooooooo, while I endorse replacing the socket/connector on your own as its so easy, you need to make sure you have a good plan for tranny fluid adjustment.