I keep hearing this scraping noise under my truck. When I slow down it makes this sound and when I accelerate. It doesn't make the noise after that and sometimes turning hard left it makes a bad sound. My brakes and pads are all good and my wheel bearings when I checked. I'm not sure if it is my u joints in my driveshaft or my dust shields. Really frustrating knowing what it is. Any advice would be helpful. Seems like a thudder too when I slow down.

 

What year is your truck? 4x4? I have a 2012 Sierra K1500 and I just put the 2nd right front hub on since I've owned this truck - I bought it new. To check the hub you would need to jack it up and try to wiggle it just like checking ball joints. That may not expose whether or not it is the hub but that is a place to start.

Turning puts a lateral load on the hub bearings and that's most often when the noise is heard though it can also be heard with straight ahead dirving.

 

It wasn’t the hub bearings they seemed to be good and had the bearings checked for all the wheels and said it was good

 

How were the hubs checked? The first hub of mine - I jacked up the truck & shook the wheel to and fro and didn’t really feel any sloppiness but the hub was toast. The 2nd hub had lots of play when the truck was jacked up and I jerked the tire back and forth (while holding the top of the tire).

 

First figure out if it’s tied to road speed or engine RPM—coast in neutral at ~20–30 mph and see if the scraping stays. If it changes when you lightly apply the brakes, look at the rotors’ dust shields/backing plates or a rock stuck between shield and rotor; also check the parking brake shoes inside the rear hat rotors. If it doesn’t change with braking, crawl under and look for shiny rub marks on exhaust heat shields, loose exhaust hangers, skid plates, or a plastic inner fender rubbing a tire. For RWD, also check driveshaft U-joints and the carrier bearing; on 4x4s, inspect front CV boots and shields.