I've had a few 8 3/4 center sections that the cross pin that retains the spider gears had started wearing a slot in the center's hub, one was about a 1/2" from ripping the hub into two pieces.

With the rear end jacked up and the tires off the ground, there was a very noticeable lack of movement between the driveshaft yoke and the tires when rotating by hand and changing rotation direction.

Check the noise out, don't assume everything is OK. Gene