What axle capacity do I need? Pick an axle that matches your trailer’s total loaded weight. If you’re running heavier gear, step up the capacity to keep everything safe and steady. What’s included in an ASTSS assembled axle? You get the full setup ready to bolt on—axle bar, hubs, bearings, seals, and studs—all built to spec so you can fit it and get rolling How do I measure my trailer for the right axle length? Measure from face-to-face on your hubs and spring center to spring center if you’re r