WINDOW-REAR 4645055 - Caterpillar

All Models With Sleeve Metering Fuel Systems
Correct part numbers for replacement bearings to use in fuel injection pump housings for sleeve metering fuel systems have been difficult to find. The same two bearings are used in each of the three housing assemblies for four, six and eight cylinder engines. For assistance in the correct identification of these bearings, the parts chart shows the original bearing number, the service replacement number, the bearing location in the housing, and the form number of the special instruction to use for installation.
The original 6N1078 Bearing used at the front end of the housing is available for parts service because it is used in other applications, but is not to be used for replacement in this application. The 5P4810 Bearing, used for replacement of the 6N1078 Bearing, is not completely machined; the bore must be machined to size after the bearing is installed. Complete details for bearing installation and machine work are given in Special Instruction Form SMHS6735, which is sent with each 5P4810 Bearing.
A correction must be made to Special Instruction Form SMHS6735. On Page 3 of the form, Step 5 gives a bearing bore dimension of 25.4127 .013 mm (1.005" .005"). Change this dimension to read: 25.413 .013 mm (1.0005" .0005").The 8N628 Bearing, used for replacement of the original 4N3711 Bearing at the governor end of the housing, does not need to be machined, but must be installed with the groove in the correct radial position. Specific information about installation of this bearing is given in Special Instruction Form SMHS7343, which is sent with each 8N628 Bearing.