Ford Repair: 2002 Windstar Trans & EGR, egr valve, ford garage

Question
Erik,
I have a 2002 Windstar SE, V6, Auto Trans that has been in the dealership multiple times for a problem that has been identified as a trans problem, but when I took it to the trans shop they disagreed. I have a terrible shake/vibration that is intermittent. It happens at many different times, I can be goin 20, 35, 50, 70 or 80 mph and it happens. It lasts about 1-2 seconds and it goes away. At times it can do 5 or 6 times in a 10 minute window or it may not happen again for days. It will happen with the overdrive on and off. I have had the trans flushed and filled three different times, they even put a solvent in there that was supposed to eliminate it, but it didn't. I'm lost!
My second question is related to the EGR valve. I have a hard fault stating defective EGR valve, 1. Is it safe to assume since it's a hard fault that I need to replace it? 2. How hard of a job is it to replace it?

Answer
Hello and thanks for the question...I'll try to help.
 For the first part of your question. It almost sounds like a torque converter lock up problem. I would have the Ford garage look in to it further.
As far as the EGR is concerned, just because a hard fault is set, it doesn't mean that the part it self that the code is talking about is bad or needs to be replaced. It is just an identifier to the technician to know where to start. The EGR might or might not be bad. I would suggest that a mechanic take a look at it.
Hope this helps,
Erik