Hey Kevin, my thoughts also... I don't like the unknown !
Regards to what caused it and damage done, broken "spring plate or disc" I'm guessing -haven't pulled the diff yet. I was planning on doing it today, this weekend I'll get to it and know more..
eLocker $1'700 that's why I'm looking at rebuilding the center and a "re pack" to a heavier brake away Lb. for the LSD
Pinion and crown $550 to $1200 if needed, at 310'000 k it may be needed..
Bearings and seals $300 to $500
Have done, Set pinion to crown $200 to $300
It starts to add up , $3000 on a 03 ??? That's why I'm thinking lsd.... all depends on where that other piece of metal came from, I'm betting that bit of spring plate has chipped a tooth of the planetary gears...