I have a 2002 Dodge Durango. WQhat does it mean when I was driving down the street and all of a sudden I push down on the gas and you can hear the engine racing but no go?

Sounds like your viscous fan. See post "03 durango acceleration problem". After you read that post see if your durango is doing the same thing. I have a 2002 Durango 4x4 with the 4.7 L V-8 and mine does it all the time.