I was coasting up to a stop light... the light turned green and when I pressed the gas... it just reved the engine. no gears at all. (the tranny made no noise, and no signs of going bad)someone told me to take off the tranny pan, and remove the tranny filter. They said there is a solenoid or somthing there, and thats probly all it needs... is this true? What is the part I need to replace?