Whinding Noise

I Have A 2001 Dodge Truck With The 5.2 Manual Tranny In It . I Have Been Recently Been Having Problems With It Making A Whinding Noise. So I Figure That The Transmission Was Low On Oil . So I Decide To Flush Oil Out . I Refill The Tranny An Transfer Case It Was Pretty Easy. Flush Then Both Out An Refill Them . I Got Out An Drove It A While Let It Warm Up . An It Still Making A Whinding Noise . Ne One Have Ne Suggestions . I Hope It Something Lil They Can Be Fix .

could be the throw out bearing making the noise...