Why does my skateboard mak a rattling noise when I ride it on a rough road. Also, when I drop the it, nose up and tail on the ground, like when you step on one side and drop it, it sounds like the wheels are not plastic. This only happens with one truck/the 2 wheels. I've tried removing the truck and wheels where the noise is coming from and tried dropping it, and it made no noise. Pls I need and answer asap.