I am constantly hearing some weird ticking noise when I change down from 4 -3 and 3 -2 and when I change up from 2 -3 and 3- 4. It is coming from the rear of the car and I can hear it when I open my windows. The sound doesn't appear to be alarming or damaging, it almost sounds as though it is supposed to be there, but then again I could be wrong seeing as I'm quite the noob. haha any ideas? help appreciated..