popping in the rearend of my 05 rubicon

[mark]

I have a server popping sound that is coming from the rearend of my 05 rubicon. My rearend fills like its binding up, and if I turn sharp and stop the rear axel is torqued in the direction the jeep is turned.
I have changed the fluid with the recommended 75/140. No missing teeth on the ring no metal frags. Only pops when I turn R or L. I have noticed that the rear locker light flashes some times. Would the locker cause this problem. Should I park it till I get this fixed?