CKL550

Just like the title, I keep hearing this clicking/clunking-ish noise from the back of the car. I only can really hear it when going under 20 MPH with the radio off, otherwise theres too much noise. When i get under the car and grab where the swaybar meets the link on the driver side and push and pull on it, it makes the noise. The passenger side is beautifully silent. both sides are tightened securely and I see no other complications. Only other info I have found on this topic refers to the swaybar bushings, not the end links. Do the end links need to be lubed? Please help this noise is all kinds of annoying!!

Edit: Progress rear swaybar with progress end links.