[El Kabong]

It's probably worth pulling off the drums in the rear to have a quick look. It's easy enough to do, no bearings to pull. The parking brake is only in the rear, btw. Or it's pretty cheap to have it inspected if your not comfortable with it.

Is it any better after it has had a chance to cool down?

Welcome to the site. You'll enjoy that Bronco.

 

[El Kabong]

Dustball's right, it sounds like power steering. It's probably just a coincidence that it showed up when it did. I read that as vibration in the wheel on the ground, not in the steering wheel. Your title & references to turning should have been a clue. :doh0715: Sorry 'bout that.