Put new backing plate assemblies on my dual axle trailer this week. 4 complete assemblies was cheaper than new shoes, magnets, and assorted springs. Set the shoes to the drum until it would not allow rotation of tire and then backed off 4-5 clicks of the star wheel. Put mark on wheel and give it a spin. Getting 1 full rotation before brake drag stops wheel. Does this sound about right to you guys? Probably re-check them in a couple hundred miles