C3.4B Engines for Caterpillar Built Machines Caterpillar

Maximum permissible wear of the main bearing journals ... 0.040 mm (0.0016 inch)

Radius of the fillet of the main bearing journals ... 3.875 to 4.125 mm (0.15256 to 0.16240 inch)

Surface finish of bearing journals and crank pins ... Ra 0.2 microns

Surface finish of radii ... Ra 0.4 microns

Width of new main bearing journal where the thrust washer is installed ... 35.165 to 35.235 mm (1.38445 to 1.38720 inch)

Width of new main bearing journal where the thrust washer is not installed ... 35.15 to 35.25 mm (1.38386 to 1.38779 inch)

The shell for the main bearings

The shells for the main bearings are available for remachined journals which have the following oversize dimensions.

Oversize bearing shell ... 0.127 mm (0.005 inch)

Oversize bearing shell ... 0.254 mm (0.010 inch)

Oversize bearing shell ... 0.508 mm (0.020 inch)

Thickness at center of the shells of oversize bearing shell 0.25 mm (0.010 inch) ... 2.226 to 2.232 mm (0.08764 to 0.08787 inch)

Thickness at center of the shells of oversize bearing shell 0.50 mm (0.020 inch) ... 2.353 to 2.359 mm (0.09264 to 0.09287 inch)

Thickness at center of the shells of oversize bearing shell 0.76 mm (0.030 inch) ... 2.480 to 2.486 mm (0.09764 to 0.09787 inch)

Width of the main bearing shells ... 26.32 to 26.58 mm (1.03622 to 1.04645 inch)

Clearance between the bearing shell and the main bearing journals ... 0.032 to 0.102 mm (0.00126 to 0.00402 inch)