My new 2017 Tacoma SR5 4x4 has a vibration in the front end at first l had no problem the after about 600 miles it started when I was stopping around 45 mph. Then it became worse, from 45 down to 10 mph. It goes away just before the truck stops. Now I have 6600 omit and I am feeling it while I drive as well. Anyone know what is going on? The Toyota mechanic said it is not rotor or tires and he has no idea on what could cause it.