My rear end is making a humming sound really badly it only gets louder when I accelerate but quiets when I decelerate I've changed the fluid multiple times found there was rust gunk build up cleaned it all up still making noise and when I drop my drive shaft and take the nut off the center yoke it just pops off when I thought it would need a wheel pullu to take off since it's pressed on but mine just slides rite off the rear pinion gear
The flange that bolts onto the pinion gear has to be installed with the proper preload as specified by the manufacturer. Usually, there is a crush sleeve and shim washers used to get it correct. It's not just a tighten the nut and go. Also, because you said there was a bunch of crud that you cleaned up, your rear wheel bearings might need replacing. After all, it's a 14 year old vehicle. Also, check your u joints for wear or slop. They are pretty easy to replace.
