CATERPILLAR Track-Type Tractors D3, D4, D5 series

List of models and prefixes

Very important remark: The CAT equipment prefix (first three figures and numbers in serial number) is absolutely necessary information for correct engine identification. But your additional information (full serial number, arrangement number, where the engine is installed etc.) will help to avoid mistakes. Sometimes the full serial number is absolutely essential information also (modification is inside the prefix).