Anyones rear diff seem to sweat a little?

Chry 8.25, seems to be comming out of the fill hole and running down the cover. You can't ever really see any coming out, but its always wet there.

Can I RTV the rubber plug?

Nope... just let it seep.

You can buy a new plug, but it will do the same in a year.

how recent have you changed the fluid? could just be overflow. mine did that shortly after i changed the fluid and while driving it would spray back and get on the gas tank.

I wouldn't worry about it. Mine's done it for ages.