[rohrmann]

If your rig originally came with the Goodyear G614, then the placard on the side of the rig will indicate the axle rating as 7,000 lbs because the G614 has a 3750 lb capacity. If the tires were the Goodyear Marathons, then your axle, even though they are the same 7,000 lb axles, will be derated to 6750 lbs to compensate for the 3420 lb load capacity of those tires.