why transmission shifts rough

Just to clarify - downshifting at 30 mph would not be from 2-1. I'm actually not entirely sure what that bump would be. I would recommend hooking up a high quality diagnostic tool (Like the Ford IDS...) and monitoring the Torque Converter, TCC (Torque Converter Clutch), as well as "GEAR" PID, which will tell you what gear is being commanded. I feel like there's a chance you may be feeling the torque converter engage or disengage depending on the situation. On normal driving and acceleration, the torque converter would engage around 30-35 mph. If you had an experienced technicain who is familiar with the CD4E automatic transaxle in that car, or a long time Ford transmission veteran, with the appropriate diagnostic tool -- you would have a good answer.

I just have to answer this bacause my 1998 Ford Contour automatic transmission does EXACTLY THE SAME THING and ONLY when slowing down. Never any problems taking off or normal driving. I took it to a transmission shop they checked it all and found no answer. Took it too another repair shop and fhey said "we dont know what is causing it at all". Just like yours. Good luck searching for an answer. If you do find one PLEASE let me know at w3zkx1@suddenlink.net.

I have a '98 Contour V6 with the same "clunking" noise while UP-shifting into 2nd. Turned out it was some sort of $60 sensor but I don't remember what it was called...sorry!

time for screen change and fluid