My 07 with 220k on the clock started locking up the left rear wheel a few weeks ago. I finally got it to a shop to get it checked out and after getting into it the mechanic says the clutches are causing the issue. He is now actively looking to see if the clutch portion of the rear diff can be replaced, if not I'm looking at close $2000 for a complete replacement.
I've never heard of simply replacing components internal to the carrier but I guess that's possible?

I'm also kicking around just converting to Posi rear with something like the Yukon gear set up or maybe an Eaton.

Anybody that can shed light on any of this would be helping me out a bunch.

 

Anything can be re-built on our rides (almost). But, if you go with a Auto/Posi differential, I'd highly recommend you replace the Ring and Pinion too. Getting a lasting adjustment on your existing would be XXdifficult. So, a rebuild of your existing assembly would be my recommendation.

 

Good write up on the G80 rebuild:
Offroadtb.com Rear Axle G80 Differential Rebuild


Ebay offering of G80 rebuilt:
Rebuilt 8 6 8 5 8 10 Bolt Eaton Gov Loc Locker Posi 30 Spline G80 New Bearings | eBay

 

Just finished talking to the shop working on my Tahoe. It seems the diff can be rebuilt using GM parts after all. The price for a rebuild was close to that of switching to an Eaton Truetrac so I chose the Eaton since I have other work going on later this winter. I'm keeping the stock 3/42 gear since I already have turned off AFM. All new seals and bearings to wrap it all up.