INSERT-VALVE SEAT 1227352 - Caterpillar

All 3400 Series EnginesSUPPLEMENT: 09/05/83SERVICE MAGAZINE, DECEMBER 13, 1982, PAGE 5.The article "New Piston Group Has Thicker Top Ring" tells about the use of a new piston group on all 3400 Series Engines. The new group has a thicker top ring with a layer of plasma on the outside diameter. In effect serial numbers were not given in this article. In effect serial numbers are now available for some engines. See the chart that follows for a list of the models and serial numbers. --------------- END SUPPLEMENT ---------------SUPPLEMENT: 02/28/83SERVICE MAGAZINE, DECEMBER 13, 1982, PAGE 5.In the article, "New Piston Group Has A Thicker Top Ring," you were told that new piston groups were used on all 3400 Series Engines. This is not correct. The piston groups in that article are only used for parts service. They are not original equipment at the factory. They are original equipment on 3406 Truck Engines and the 3412 Engines in D9L Tractors. Make a note of this in the article.--------------- END SUPPLEMENT ---------------Reference: Service Magazine, June 21, 1982, Page 5. The article "New Piston Group Has A Thicker Top Ring," tells about the use of a new piston group in 3406 Truck Engines. The new group has a thicker top piston ring with a layer of plasma on the outside diameter. These changes make the ring stronger and give better resistance to scuffing.Description of Change: The new design piston and thicker top piston ring are now used on all 3400 Series Engines. The new piston and ring will have a longer service life.Adaptable As: The new parts are direct replacements for the former parts as shown in the chart. The former rings and pistons can still be used for parts service, if desired.