Your torque converter could be friend and acting abnormally. It can be an expensive fix if you don't DIY.
What you need to do is take it to the Ford Stealership and discuss your problem with the Tech. Don't tell him why you think it's doing it just describe your problem as well as you can. Maybe take a pad and pen with you when you drive and write things down like the MPH and RPMs when you feel certain vibrations or noises. This information can be very relevant and important.
Tell them to give you a full report on their diagnoses before they start any work. This way you can just bring it back home with all their good advice. Don't get freaked out by the cost of the procedure if it is something like the torque converter, Stealerships will always charge you absurd amounts of money and tack on things that aren't necessary just to boost their commission.
If it is the torque converter I can guide you step by step on the replacement. It may seem daunting but it really isn't. They'll probably charge you like 2 grand to switch it out just because they have to take the transmission off the engine to get at the converter. You can buy a new torque converter for 150-200 off ebay and a new torque converter seal for 18 bucks. That is all the parts you'll need! It is amazing how much they charge for their expertise and time, isn't it?
After those parts you'll need a 20 dollar set of metric sockets, a 20 dollar ratchet, a 30-100 dollar torque wrench, and some Mercon fluid to put in the new torque converter.
Get back to me on your decision. | 
