M939A2 Brake Drum. Meritor Part number 3219S4829, also 3219-E-4815, 3219-E-4815S. Fits the 5-ton AM General A2-series trucks with CTIS and Rockwell axles. Please verify your part number. Casting numbers 3219S4828, 3219S4829,3219-E-4815, 3219-E-4815S. Weigh is approximately 115 lbs. 1WH1C+T1R