Sounds like the rear main. Unless it's something leaking from above in the back of the engine and tracking down into the bell housing (unlikely). This repair requires removal of the tranny, drive shaft, associated linkages and wiring, also flex plate and crankshaft flange. Not your Sat morning DYI project. Most of the cost is labor..Good luck.. BTW, you can let this go for a while, if yo can tolerate the droppings. It will only get worse..
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..