[tcrist]

I agree that if it did not leak before then it should not leak now. That though does not mean that the transmission shop did anything wrong.

It does not cost anything to look and see what is wrong. Work on it, NO, look at it and try to figure out what is leaking, yes.

Odds are the transmisson shop did not seal something or used an incorrect gasket or seal somewhere. That said, you should not have to pull the transmission out again, take the car to them complete and let them look at it. You could have damaged the rear seal installing the driveline.