The axle code, which is a two-character code, is stamped on the front passenger side axle tube to the left of the carrier case. For example, axle code PX G70621 found on a 1977 Trans Am would be deciphered as; PX = Ring Gear size, G = Manufacturer, Chevrolet Gear and Axle, 062 = Julian date which is the 62nd day of 1977 or March 1, 1977, 1= is the shift when built, in this case 1st shift.