Just an update. I ended up taking it to Ford with the old part still in, and with it jerking and bucking. I told them that the synchronizer was squealing, but left the jerking and bucking part out, out of simple mistrust of the dealerships in general. They called and said it was ready so my wife picked it up. On her way out it did the jerking and bucking again so she took it back. They kept it in the back for around 30 minutes and the problem was solved. The service advisor told my wife that one of the coils had gone bad during the synchronizer replacement, but that the mechanic had another one in his tool box that he put on, thereby saving us an additional $100. When she took it back the second time they told her that the coil wasn't tightened down and that that was all he had to do. I don't know what they did the second time around, but as you know that motor doesn't have the coil on plug setup, and I know the main coil pack wasn't loose.