2005 Silverado Front diff howling
 

I have a howling sound when in Auto or 4x4 so decided to have it checked. Chevy shop siad it needs a rebuild. I have the GM cert used warranty and powertrain left for that matter so it will be paid for. I'm just curious how common this is?? I have 47,500 miles on mine. I don't think the 4x4 was even used much by the last owner because they spent winters in Arizona.

What parts will be replaced in the rebuild?

If its a constant howl it will for sure need a ring and pinion, and probably bearings.
Its hard to say what caused it without seeing it in person.
i havent heard of them eating ring and pinions, just the actuators ocasionally going bad.

my 05 has been fine (54k miles) and i use 4x4 quite a bit in mud and snow in ohio.

Ok. Just wondering if there are certain parts I should be sure to make sure they check. I know they are supposed to be the experts, but I wasn't sure what things could be damaged from the front diff being loose or out of tolerance.