2011 Silverado LTZ

I started hearing/feeling a single "knock" or bump noise coming from rear end when I turn the truck to left quickly like when I pull into a street or driveway. Any suggestions where to start trouble shooting? Thanks in advance.

I would put two jack stands and have the rear tires off the ground. First look for any rear end lube dripping from the axle. I found a lot of older GM truck vehicles rear wheel bearings go bad. Rotate the tire and listen sometimes you have to remove the caliper. So your sure where the noise is coming from.