I recently bought a stripped 04 sedan and rebuilt it. It's ready to go except for it's making a clanking sound (like it's slamming into gear) when i shift it into 2ND, as well as when it shifts into 3RD. If i pull over and take off again, it still does the same thing. Also, when i put it in manual mode, it continues to shift by itself. I thought it was the tranmission and so i got it swapped twice already but the symptoms won't go away. any ideas?