[jakeru]

Good stuff. I don't know that I agree that your coffin arm bushing has any significant or objectionable wear. Rubber looks good - no cracking or tearing. The place where you refer as seeing daylight through being a problem in itself is not actually a problem in my opinion - this is just rubber casting flash that's been torn from the bushing motion, which is by design. If it bothered you, you could use an x-acto knife and trim off this casting flash on a new bushing before you installed it if you wanted, and tuis very thin amount of rubber is not going to significantly affect the bushing's function.

You are seeing some contact patterns that inside the rubber bushing is moving relative to the outer part under track loads, and replacing the bushing with stronger material or that's more rigid in shape (like without the holes you mentioned you can see daylight through, or with smaller holes) would keep it from moving around as much when using it. There's a good chance this could allow the alignment to not move around as much dynamically, and basically give you more grip and better handling performance at the limit by maintaining better alignment under cornering and braking forces, although hardening the bushings could cause more noise/vibration/harshness for street driving application.

Nice vid, just wanted to share that info / my opinion for what it's worth!