Used Cars: Return policy, transmission problems, transfer case

Question
I purchased a vehicle one week ago from a dealer and signed an "as is" document.  The vehicle has transmission problems (transfer case - no reverse).  Is there some kind of law that would allow me to return this vehicle to the dealer within a certain amount of time and demand my money back?

Answer
There really is not a lot you can do, legally.  I will tell you that you have your best chance within 30 days of purchase.
Really it is just one of those things that hopefully they are dedicated at having a good reputation, and will make things right, without it getting legal.