Is my differential going?
 

SOLVED RATTLE: Axle boot clamp came loose and was smacking the suspension parts as it rotated. Clunk still there.

Recently developed this metallic rattling above ~55mph. Happens in all gears and when rolling in neutral. Initially took the car in because I had a clunk while shifting/getting on and off the throttle sometimes. Mechanic swapped my CV cups side to side to alleviate vibration under acceleration and also had the axles replaced with OEM ones while swapping the cups to see if it would fix the clunk, no go. Clunk is still there and now this rattling developed less than two weeks later. Also, the rattling happens after the car gets up to temperature. Isn’t present when cold. Mechanic did mention that the diff my be on it’s way out. Wanted to get some opinions on here. Here’s the rattling sound:


Thanks!

What does the magnet on the drain plug of the diff look like?

I haven't checked that yet. Going to get underneath her this weekend and check the drain bolt, mounts/bushings, axles, and prop shaft.

make sure the axle nuts are properly torqued, based on the new spec not the old spec in the shop manual, since the axles were swapped that might be a logical place to start.

Definitely not the axle click. Dealt with that before and know that sound 100%.