When driving at 45-55 mph and let off of the accelerator there is a noise that starts. From inside the car it sounds like it is coming from the transmission area. It sounds almost like when you have plastic gears that don't mesh or are stripped. The trans. fluid is full. Any ideas? The car has 230k miles.

 

Get underneath and inspect the CV joints. Could be one just starting to go. Otherwise if noise from inside the transmission, change the fluid and filter and keep fingers crossed.