i have a 518 that makes a noise that starts at about 30mph, it is speed related, not rpm related. the best way to describe the noise is the clicking sound a tranny makes when you put it in park when car is still moving forward. took it to a tranny shop [ same guy that built it ] and he found fileings in the pan. he figures that since the od unit is from a diesel and the park rod is from a gas valvebody that the park strut is a different length. can anyone confirm this? would this create fileings?