Usage:
3208, 3304, 3306, 3406, 3408, 3412, 3508, 3512, 3516, 3606, 3608, 3612, 3616, D379, D398, D399 Engines
Reference: Service Magazine, May 12, 1986, Page 8; "Identification Of Crankshafts For Marine Society Approval". Service Magazine, June 23, 1986, Page 6; "Standard Diameter Crankshafts Meeting Marine Society Approval Are Available Through Caterpillar Remanufactured Products Program".
Caterpillar crankshafts are marked with code letters from which their physical and chemical properties can be traced. This heat code identification marked on the crankshaft consists of three to five letters (ie. OEA or SRMNV). The first letter of this code is an A through Z and indicates the forger of the crankshaft. The second through fifth letters of the code are limited to A, E, D, K, L, M, N, O, R, U and indicate the heat code.
The code letters are stamped or forged on a steel identification boss located on the side of a crankshaft web (cheek). See illustration. Dealers requesting crankshaft physical test reports must provide the complete crankshaft code. The following chart shows the location of the crankshaft heat code.
Crankshafts are inspected and marked by the Marine Classification Society. Their identification marks are located as close as possible to the heat code letters. If it is not possible to mark the crankshaft on the same crankshaft cheek as the heat code, the marks will be placed on one of the adjacent webs on the same side of the crankshaft.
Crankshaft nomenclature. (Cheeks are numbered from front to rear.)
Crankshaft physical test reports can be obtained through the Engine Scheduling and Orders Division. When requesting this information, always provide the engine serial number.