COVER 4451677 - Caterpillar

3176 (7LG, 2YG) Truck EnginesReference: Special Instruction, Form No. SEHS9246, "Using the 4C4054 Unit Injector Sleeve Replacement Tool Group "Description of Change: A new unit injector sleeve is used in the cylinder head groups. The new injector sleeve looks identical to the former sleeve. But, the new sleeve has a more consistent hardness which provides the following advantages:* The new sleeve has a higher minimum hardness which allows tightening the 4C6730 Roller Expander (see the Reference) to a torque of 100 lb in. Some former 4P7135 Sleeves did not provide enough resistance to achieve the 100 lb in specification. This could result in an incorrectly installed sleeve.* The higher minimum hardness will reduce the possibility of stripping out the threads in the sleeve when removing the sleeve with the 4C5542 Puller (see the Reference).* The new sleeve also has a lower maximum hardness which eliminates the difficulty of reaming extremely hard sleeves when using the 4C5538 Reamer Head (see the Reference ).
Location of the injector sleeve in the cylinder head.Adaptable To: The new 1047898 Injector Sleeve is a direct replacement for the former 4P7135 Injector Sleeve. The former injector sleeve is canceled.