Hey all. If someone wouldn't mind checking out this video...I'd appreciate it. The video is with both rear wheels and discs/rotors off, FYI.

https://youtu.be/hyUt542CLGI

Right now the noise is just a quiet chatter/rattle that I can hear with the windows down, going slower than 30 (any faster and road noise drowns it out). I thought it might be rusty e-brake parts rattling around, since the sound goes away if you press the e-brake pedal down even a little... but this noise with the rotors/discs off makes me think I need wheel bearings. I can actually feel that vibration in the axle tube when rotating it, but I don't feel any play in the axle itself, aside from the normal in/out. Thanks for the help!

It's probably the wheel bearing starting to go. Unless there is some damage to the differential gears its the only thing that could make noise like that. When mine went i could only hear the noise at low speed, but after a few weeks it got louder and then i developed play in the drive shaft.

Pretty easy job, make sure you get the right tools for removing and installing new bearings and seals. Check the axles for damage where the bearing rides, if there is no wear then you can reuse them. Post pics of the axles too so others can see what you are dealing with.

Well...dang. It doesn't seem to be the wheel bearings. I crawled under there to listen while my wife spun the wheels, and the noise is definitely coming from the differential. Is there a "normal" amount of differential gear noise? I've changed the diff oil about every 30k miles, so I'm not sure how the differential gears could have been damaged. I did just tow a uhaul trailer from Maine to Florida, but it was only loaded to about 2500lbs. Besides, I would think that'd cook bearings, not chew up differential gears.

Just checked the gear oil...it's pretty dark, and I wiped a sizable glob of silver goop off the magnet. I don't remember how much silver goop is normal...

The only normal sounds i think you should hear from the dif are the gears whining, not grinding and making horrible noises. You probably have trac loc, and i don;t know much about that. Hopefully someone that knows more than me will respond. It could be the trac loc and not the gears themselves.

Well...I feel pretty dang stupid. It was the brake shoes coming unseated, which pushed the little parking brake switch slightly out, making it hit the wheel stud heads as they rotated.

The terrible noise in the video? That's the noise an open differential makes when you rotate one axle.

from: https://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=2830861



On the bright-ish side, I found out that I need to change my differential oil again, and that replacing the parking brake components is a slight PITA, but doable.

I should probably still do my wheel bearings though...130k miles, and I bet they're original.