4wd issue (s) 2005 silverado

So it's clear that the front diff had been driven dry of gear oil. I'm gonna go out on a limb and say it has bearing damage. A couple big symtoms are of course loud whine. In 4wd auto I can drive safely to 40kph before it starts bucking and hopping with a heavy deceleration to a dead stop without hitting the brakes. I'm forced to hit the 2wd button to continue. In 4hi I can drive up to 60kph and I can accelerate. As soon as I let off the gas the front dives and begins bucking in the snow. This causes the truck to fish tail. I know worst case is a new front diff but I've heard bad wheel bearings or cv axles could bind. I've only had this truck for a couple months and I've been trying to tackle what I can. Now that snow came early i was able to actually test the 4wd properly. Any experience and feed back are welcome thanks