I have a 2001 Subaru Impreza 2.5 RS Coupe. Right now I have a clicking and clanking that is coming from the back of my car. I think I may be missing teeth in my transmission. It only clanks when I take off, accelerate and slow down, and it seldemly does it while I cruise. I don't want to take it to the shop with out me knowing what it might be or what it is.