Loud Bang some times after backing up .

Hi
I have a 2003 GMC Yukon XL 1500 4 WD
Ive been getting a loud bang ( like a hammer strike on the front frame) on occasion only after backing up and it happens after the truck moves forward a bit.
You can almost feel the truck loading up and then it gives with a loud hammer like bang.
Ive had a tech check the front end and do an alignment. I had thought it might be a brake hanging up .

Any input would be greatly appreciated
Thanks
Brian

Update

I took the advise of someone on another forum and checked the wheel bearing hubs. The front passenger hub bearing was shot and binding . changed that out and all seems good

Congrats and thank for posting back here!