changing the fluid on the transmission if it already has a problem might make the problem worse. you probably dont need a whole transmission. the one you have is fixable. it would be necessary to take the vehicle to your nearest transmission shop for further diagnosis to determine if the problem is internal or external. They might tell you that the transmission would have to be removed from the vehicle in order to determin the problem. if so, most shops offer to do this at a reasonable price.
The 2003 Chevrolet Malibu has a 4-speed automatic.
The 2007 Chevrolet Malibu has a 4-speed automatic.
The 2006 Chevrolet Malibu has a 4-speed automatic.
The 2005 Chevrolet Malibu has a 4-speed automatic.
The 2008 Chevrolet Malibu has a 4-speed automatic.
The 2001 Chevrolet Malibu has a 4-speed automatic.
The 2002 Chevrolet Malibu has a 4-speed automatic.
The 2004 Chevrolet Malibu has a 4-speed automatic.
The 2009 Chevrolet Malibu has a 4-speed automatic.
The 2010 Chevrolet Malibu has a 4-speed automatic.
The 2012 Chevrolet Malibu has a 6-speed shiftable automatic.
The 2013 Chevrolet Malibu has a 6-speed shiftable automatic.