Well, from the land of the internet it's going to be very difficult to say where it's coming from.

The first video with the LJ locker popping is likely from the ring not fully disengaging and just barely contacting the teeth that the ring slides over, that's as close as I can get in layman's terms.

There is a chance it's not the diff at all. It could be a bad bearing, bent axle, bent flange, who knows.

Check out this video I found for you: https://www.youtube.com/watch?v=f45y1fzYXA0 .
This will give you a fair idea of what to expect when you pop the cover, as well as how to disengage the ring, if that's what it is.

Now as far as the spider gears go, there is no way to get a good look at them. You can get a flashlight and peer into the windows to get an idea of the general health of everything, but you can't see much.

If you want to try and figure out what's up, chalk the wheels (obviously), drain the diff and lift the passenger rear wheel off the ground, pop the cover. Any apparent metal shavings or "glitter" in your diff oil means the diff is eating something and it's time to get it to a shop.

With your face near the diff, spin the wheel and listen. If the popping is coming from the right side of the diff, where that ring is you can see in the video, then chances are good it's a problem with the locker. If that's the case I would try and push that ring to the right with a screwdriver, just like you see in the video. It should be flush with the magnet on the right side of the diff when unlocked. There is a chance that this is a one time F-up of the locking mechanism, but if it happened once, chances are good it'll happen again. These lockers wear very quickly when used a lot. I've seen the magnet weaken after a lot of use, but your Jeep isn't old enough for that. Most of the time a lock ring that doesn't disengage means a bent housing, which is loading up the carrier. It can be hard to tell, but if the locker won't disengage it's time to figure out what the deal is, not just throwing new lockers in. For the record, ARB's don't have these issues and will run in a mildly bent housing just fine. The one easy thing that *could* be happening if the locker won't disengage is that these diffs are designed to run with LSD gear fluid, if the diff was filled with straight gear oil at some point, it's possible that the locker ring is being held up by friction, as LSD makes everything a little more slippery.

If there is popping coming from the diff itself, to the center leftish location of the carrier, then it's something inside the diff, likely the spider gears. If that's the case, it's also time to get it to the shop ASAP. I wouldn't do too much driving on it. If you don't get a popping you might what to jack up the other wheel and start trying to make it pop. If it's the ring and pinion you should see signs on the ring gear that something is up. It's worth noting if you can feel the "pop" through the wheels as you turn them. If you can't see anything but you can feel resistance as you turn the wheels, something is wrong.

All of this being said, while I'm all for people getting in there and learning about what makes this work, if you have a pop coming from the diff, it may just be time to take it to a good shop and pay them to diagnose. Chances are really good that you won't be able to handle any of these outcomes from your driveway. Keep us posted!

 

Thanks for all your help.