Large metal chunks on rear diff drain plug

2nd rear diff flush i did on my truck. this time around i noticed more larger chunks then just a little shavings. First time I drained it was because I pulled the driverside axle shaft to do seal and bearings. Had a machine shop that had the tools and the press. That was about 2 years ago now
But Seemed like a few months after that I had been hearing a binding/clunk coming from rear. I thought it was the drive shaft but carrier bearing and u joint move smoothly with no binds. Also they where greased. Noise seems to be coming from where the diff bolts on the driveshaft. So I went to drain my rear diff fluid and found these chunks. The chunks look like just mush in the picture but when u rub it. Diff fluid was dark but not to bad. I could post a video of the noise but 2 mechanics say they have no clue what the clunk/binding noise is. so im just guessing but think something is definitely wrong with my diff. Anyone got any ideas I dont know if I should tear into this diff now or not.

 

That's not normal at all. How many miles in the 2 years since the last drain and fill? I've seen diff fluid drained at 30k that is dark and then the same diff has a fluid change 30k later and it looks brand new. Your fluid after 2 years of normal driving should not look like that. I suggest it's time to pull the 3rd and see what it looks like. I bet you'll be looking at a rebuild or a used diff at a yard sooner that later.

 

Definitely under the average miles for 2 years id say 8k miles. dont drive much since I been hearing this noise but the fluid was a dark Carmel color. Did my transfer case when I did the rear and it wasn't as dark. But yah I figured as the sounds seem to come from my middle rear of the diff where it bolts to the driveshaft. Wondering if they shop i gave the axleshaft too pressed in the bearing and race correctly.