Tire Problem Resolved

As suspected, the sound in the rear wheel was coming from the tire pressure sensor which had detached itself from the wheel and was thrashing about for 3000 some odd miles. Once we got the tire off the rim, we found the different parts tossed around. No damage to either the tire or the wheel, so a new sensor was installed, tire remounted, and back on the street. Good to know in case the same thing happens in August ...