PULLEY-TIGHTENER 6N3641 - Caterpillar

D379, D398 EnginesSUPPLEMENT: 12/10/80ENGINE NEWS, OCTOBER 22, 1980, PAGE 1.In the article "New Basic Oil Pump Groups Use Hardened Gears For Longer Service Life", engine serial numbers are now available when the new parts were put in effect at the factory. Add the serial numbers that follow to the article.
--------------- END SUPPLEMENT ---------------Description of Change: New basic pump groups are used in engine oil pumps for D379 and D398 Engines. The new basic groups use new shaft assemblies and new idler gear assemblies with hardened gears. The new harder gears will have better resistance to wear than the former gears, and longer service life is expected.Adaptable As: Each of the new basic oil pump groups is a direct replacement for the former pump group or assembly, which is canceled. Also, each of the new gear assemblies and shaft assemblies is a direct replacement for the respective former part, and all the former parts are canceled. Since only the shaft assembly and gear assemblies are changed, installation of these new parts will change a former basic pump group or assembly to the new group. While each of the new parts is a direct replacement for the former part, the recommendation is to use the new shaft assembly and two idler gear assemblies together in the same pump.