Here's a puzzler for all of you- 1999 Escort LX automatic, 145K miles. This clunk comes and goes but is more prevalent during colder months. On acceleration from a stop, when the automatic shifts from 1 to 2, it shifts and the rpms drop and maybe a second after the shift, I get a defined clunk. The engine mounts are all fine, I've had the front sway bar and steering bushings all replaced, I just did both rear struts and springs, and all the ball joints, wheel bearings, and other bushings are in very good shape. The transmission definitely shifts and it's not slipping. It also seems more pronounced when I drive the car for a while, shut it off for a few minutes, and then drive it again. Any thoughts on what to check??? I'm stumped.