Trailblazer squeals after front diff. replaced

I have a 03 EXT trailblazer. I just purchased it with 50,000 miles on it back in march of 08.
After our first snowfall I of course tried out my 4wd, It didn't quite exactly work. Long story short, the dealer replaced the front differential(used).

I just picked up the truck last night, the 4wd works fine now. On my way home I shut off the heater/music and noticed a loud humming/squealing noise coming from my front end. It matches with tire speed, gets louder as my speed increases. My first thought would be the brake pads, but they weren't making any noise before they replaced my front differential. Sounds like its a bearing or cv shaft bt there is no shaking/vibrating.


Any takers?

thanks
Justin

Welcome to AF. From here we have no way of accurately diagnosing this, get it back to the shop and question them in regard to this, if this was not there before they worked on it.