The suspension in the Autocar dump truck kit is made by Rockwell and is not exclusive to Autocar. The axles are also Rockwells and could be found on Autocars, Kenworths, Peterbilts, REO, and as a rarely sold option on International trucks as well. The weight rating for the axles was 38,000-58,000# while the suspension had a weight rating of 50.000-70,000#.