The pin that pushes into the block that supports the spring and self-adjusting rod fell out and bit into the drum. I found it out because the brake pedal was getting spongy and the anti-lock braking system was running at long intervals due to too much moving of the shoe the pin had fallen out of. Luckily I have a manual transmission so I could slow the truck down enough to avoid the accident. I pushed a needle back in from an old shoe until I could buy a new pair of shoes from my local auto parts store. I'm glad I lived to write this review. Maybe it was just an accident, but one of those shoes was bad. I cannot recommend them based on my experience. All overlays were kept on for the short time they were on my truck.