Originally Posted by JKFlipFloop
It is definitely engine oil and comming from that little notch in that cover.
Unless there is a leak above that can get into the housing on top (very rare) then I would say you are looking at a rear main seal. On a Dodge, it can often be replaced without pulling the engine, but not always, and you will always have to pull the transmission to get at it.
Not particularly easy or cheap repair. 100s of dollars labor and about $10 for the part.
The good thing is with an automatic (no clutch), the oil will do no real harm except make a mess of the entire underneath of the van, as long as you keep the oil full. It will get progressively worse, and may eventually lower the oil pressure a little bit.
You can try running some of the "oil for older vehicles" as they contain some seal softeners which sometimes will help. In an old vehicle there is little they will hurt.
How many miles on the engine?