Finally someone with the same problem! My car makes the same chattering sound during gearchange...and the first Contour I owned did the same thing. I think the worst scenario is when you're driving on a narrow road between two tall buildings. I had Ford and a tranny shop check it out and they couldn't figure it out. I also test drove a newer SVT recently and noticed the chattering in that car as well. It wasn't as noticeable but the noise was there. I'll agree with HETFIELD...as long as the gearchange is precise, then your tranny is OK. It's -20 degrees celcius here today...anybody living with this weather knows how tough it is to engage gears first thing in the morning in a Tour.
