tranny leaking at speed sensor interface

for a while, my old 5spd speed sensor was broken, and leaked fluid out of the top, where the cable enters it. i replaced it a month ago with a new one from autozone, and it worked fine for a couple weeks. when i had a look at her after a drive yesterday, i noticed that the interface is leaking- not out of the top of the sensor like before, but between the transmission case and the speed sensor flange. i can see tranny fluid bubbling out when the transmission is cooling down.

its not overfilled. its new, and the o-rings look fine. any ideas? could i just put a really thin o-ring between the two pieces of metal?

the transmission lost around a half a quart of fluid over a few thousand miles, and im sick of worrying and checking on it and refilling so frequently. this was why i boguht the new speed sensor to begin with.

anthony

just remembered something else: when i pulled the leaky sensor out just recently i noticed a few tiny spots of coolant mixed in. i dipped a napkin into the fluid to see if there was a lot of coolant in there. apparently not. so i just figured i had a leaky gasket somewhere, and the level wasnt dropping quickly, so id just deal with it.

could this have anything to do with the leak?

should i do something about what appears to be a very slight internal coolant leak?

anthony