We have a Curt 16k slider as well, and were advised by the installing hitch shop that, depending a lot on road conditions, to expect some "clunking". Apparently with the Curt, the clunking is caused by the built-in "play" between the quick disconnect pins which hold the hitch to the mounting rails, and is considered to be "normal" . My hitch came with a model #16900 spacer kit, consisting of 4 rectangular rubber spacers that mount between the hitch and the rails, hopefully to minimize the clunking. I have delayed the installation of the spacer kit yet, as both our 2017 Ram 3500 and our 2018 303RLS are brand new, so haven't experienced the clunking situation yet - first trip in the spring will tell the tale !