Just posted a reply regarding Carlisle HD tires which prompted me to "really" inspect my HD's. While crawling around on my hands and knees I thought it a good time to thoroughly check the truck tires as well.
Found a large bulge and major deformation in the tread of one rear tire.
These are Wrangler LR Es with about 35k miles on them. Tires have been well maintained, and rotated. Been watching them pretty close lately since they are not wearing as well as I had hoped so I know the problem hasn't been there long. But now, replacement is imperative.
I bring this up only as a reminder, since we pay so much attention to our trailer tires, to inspect the truck tires with the same passion. I feel pretty lucky I wasn't half way to Grand Junction, CO next week and found this problem the hard way.