I have a 2021 200 with BP51 Suspension on it. Soon after install I had a pretty annoying squeak coming from the back. I read BP51s were shipped with a bad set of washers. I contacted ARB and they sent me new washers no charge. I put them on and the squeak is gone. Shouldn't have been there in the first place but I was stoked they fixed it for me. Now it seems like there is a faint thud coming from the back. The two middle washers they sent me have collars on them. My theory is the collars might be a little too tall so when they are sandwiched there is a void between them (see diagram below). The void allows the shock to move up and down in the mounting hole due to washer collars. I have the nut on the top of the shock cranked down tight. No noise on asphalt, but faint thus on bumps when I hit the bumps and dirt. Anyone else come across this, or is my theory way off? I took a look tonight really quick. I can feel a little void behind washer B, but I can't move the shock. Just wondered if anyone had this issue before I spend the time to take it all apart again.