The plane which is defined by the head-to-foot and anterior-to-posterior directions in the human body. A stack of images acquired in the sagittal plane separates images by their left-to-right locations. The mid-line sagittal plane bisects the left and right half of the human body.
Under heavy braking, the rear tires lock up and the axle begins to bounce; the amplitude of the bounce becomes so severe that the tires finally develop enough traction (when slamming hard against the pavement) to rip the whole axle assembly free of the vehicle.
You can tell if the wheel bearing is shot by jacking the truck up til the wheel is off the ground, grabbing the top and bottom of the tire and try to pry it in and out. ANY movement is wear. A stocker will not move. Ours were worn to the point of more than 2 slop at the tire with 50,000mi on the truck.