I bought these to tow a 5 wheel trailer to keep my truck from squatting or swaying. They did well for that. However, when the truck was empty, they would make the truck bounce like a pogo stick at the slightest bump and make loud clanking/rattling noises that were very noticeable. I tried without the extra padding, which is negligible. Difference. My Chevy 3500HD had rubber bumper covers that were replaced with these anti-vibration blocks. The rubber fender pads had a 1 1/4" diameter oval center plug. The sway stops only had a 3/8" screw, so they would slide into the oval hole no matter how tight you tightened them. I would order around asking for a refund but I have two days past the 30 day claim.