Mild clunking sound from rear!

Hey all, I have a 2016 TRD Off-road with 180k. Halfway through a long drive on the highway yesterday I started to hear a mild tapping/clunking that sounded like I was driving on a concrete road and the sound was coming from the tires rolling over the seams each slab makes. However, I wasn’t anywhere near a seam and I noticed it everywhere even at parking lot speeds and it has gotten louder since. I replaced the rear diff fluid 5k miles ago. Old fluid looked new after 30k and I’m positive I did the procedure correctly with about 4qts oil, new washers, and torqued. I also greased all drive shaft points at that time and did not note anything abnormal (pushed a bunch of old grease out but none were dry). My suspicion is one of the drive shaft U joints has developed some play that’s making the noise. Haven’t been able to jack it up yet, but on the ground in park I couldn’t wiggle any play likely because under tension but I’ll investigate further. Anyone seen this before? It is the long bed so I believe longer drive shaft (much fewer long beds out there so maybe less of a common issue). The threads I find all have to do with suspension noises. Thanks!

*update: disregard, I’m embarrassed to say the 90 ftlb lug nut torque was insufficient

 

Do your lug nuts thread on easily by hand all the way down with no wheel on? You'd want to make sure they're not stretched.

 

Lured by title. Disappoint