Building a Horse Trailer Continued

I've finished the chassis work on my trailer. I added steps, a heavy duty bumper and put in all the reinforcements. I sandblasted it, and then primed and painted it. I also completed the electrical rough-in. I took it for a spin and was well pleased with the pull. I only noticed one bit of shudder at 50 mph that subsequently vanished above 55 mph. I rechecked all the torques and found one wheel's lug nuts insufficiently torqued, three of the bolts on the axle hanger system below specification, and the thing now glides at all speeds. I  torqued the u-bolts for the axles to 50 foot-pounds and the axle hanger bolts to 75 foot-pounds. There are some photos of the completed chassis below the break.