I replaced both rear shock, bumpers, and all the related hardware. I did the work myself. All OEM parts. When I took it for a test drive, there is a lot of knocking noise coming from the right rear on bumpy roads at low speed. Highway speed is great. Checked all the bolt to see if they are tight, where they are. I thought maybe the rear sway bar end links are bad, but they are in pretty great shape. I had one of the tech at work look at it and noticed there is a very small gap almost about a mm or 2. They are thinking it's the shock but I'm thinking it's the bumper (4834175010). If you bounce the vehicle and have your hand on the assembly, you can feel the knock. I suppose I could replace the right rear again, but I want to drill it down to the component that is actually causing the noise.

Anyone experience this?