Can anyone identify this driveline pop?

So here is the story, and at this point, I am looking for ideas to the cause of this noise. I've kind of made my decision on how to proceed, but I am looking for info or just maybe someone has been there and had the same issue. I posed up on an f.b. page of this noise and until I got it on a lift I had no further information. So I've only been wheeling/trail riding in a 4x4 for the last 2 years. I usually ride dirt bikes but have ventured into the 4x4 world just ever so slightly. This past weekend was only the 2nd trip out with the 4R for me. I found a hill climb and the rut/dip was spaced enough to put all 4 wheels into the holes/dips. The dips also had the suspension crossed up/diagonal wheels in the holes. I attempted to walk up it slow but just slipped. I turned on the rear locker and made 2 more attempts. The 3rd and last one I gave it a little more of a bump and when it started to climb I had 2 very loud snaps/pops from the driveline. It was almost as the truck bounced up a bit and when it came down and loaded the driveline something gave free. I initially went straight to cv axles. To my surprise nothing was out of order. Finished the trail/climb checked all under it on the side of the trail with no visual issues. The 4wd shifts in/out, locker locks and there is no noise driving in 2wd or 4wd. We drove another trail and then drove home 110 miles and had no vibration/noise/ any issue. I brought it into work tonight and checked both cv axle inner and outer joints, the boots are not twisted, no visual cracks in the bodys of the joints, no play or slack. i did not pull the boots to check inside. I checked the drive shafts and universal joints. All appear to be OK and show no damage or witness marks. I used a bore scope in the front diff fill hole and inspected the ring and pinion gears. No chips or damaged teeth, i checked the transfercase the same way but was only able to see the upper gear but all looked OK. I checked the rear diff but could only see 1 spider gear and I have no noise from the rear so I'm ruling that as ok. At this point I do not see anything out of place, and the plan is to move on until it shows itself but I'd hate to find it on the trails. The other consideration to this is I'm not running a sway bar, 6112 front and 5100 rear for a total of 3 inch front and 1 inch rear lift, 285/70/17, aired down to 20 psi. The only visual thing I found was the right rear wheel well has the rubber pulled off the seat belt bolt that sticks through and until I did a search it appears to be normal. I also can not duplicate the noise or the intensity since. So is it a possible cv axle? Transfercase chain? Front axle a.d.d. lock collar? I am open anything at this point.

 

Intermediate shaft for the cv possibly? If would effectively give you 3wd if that makes sense

 

Possibly, I've only had experiance where they break and are broke. The unknown at this time of what/where it came from is killing me lol

 

Sounds to me like the rear diff locker engaging, sometimes it will pop like that when engaging it

 

Any long term side effects if this was the case? Like I said I engaged the locker, the light went solid but it's possible it wasn't fully engaged.

 

If anything broke, you would have felt/heard it on the way out, I'm sure it's fine

 

If it’s solid, then in my experience, it’s fully engaged. Are you sure it was solid though? Did you hear a click from the diff when it engaged? If you put the locker on that specific spot, it makes sense it’s the locker clicking in under load.

I think if it was an actual broken shaft somewhere, you’d know about it after all your inspections and driving.

 

I am positive the light was solid and I know this because I said to myself after I pushed the button the light blinked maybe 2 sec and went solid I was like wow, that was fast. and thought nothing of it. I did try like I said 2 or 3 times prior to the noise after I locked the diff so I can only assume it is or was engaged.