Originally Posted by ADCX Rob:
The combination of casting/parting lines on the wheels, with rubber traction tires and overall light weight, adds up to the observations you are making.
You can fine-tune the wheels by truing them with a file/tool bit(as in a lathe - loco upside down in cradle - engine running) and replacing the tires with fresh, even ones, or the Stewart/Calumet 2505/192-2505 "Super Traction Tires".
Would it better if it replace truck assembly with good wheels?