G3304 and G3306 Engines Caterpillar

Before final installation of the main bearings, install the main bearing caps without bearings. Tighten the nuts on the bearing caps according to the engine's specifications. Use the 1P-3537 Dial Bore Gauge Group to measure the bores in the block for the main bearings. The Instruction, GMG00981 is provided with the tool. Ensure that the bores meet the engine's specifications. Refer to Specifications, "Cylinder Block".

The maximum error for alignment of the bores is 0.08 mm (0.003 inch). For alignment of the bores, use the 1P-4000 Line Boring Tool Group. The Instruction, SMHS7606 is provided with the tool.

Connecting Rod Bearings

The connecting rod bearings fit tightly in the bore in the rod. If the bearing joints are fretted, check the bore size. This can be an indication of wear because of a loose fit.

Connecting rod bearings are available with 0.63 mm (0.025 inch) and 1.27 mm (0.050 inch) smaller inside diameter than the original size bearing. These bearings are for crankshafts that have been ground.

Main Bearings

Main bearings are available with a larger outside diameter than the original size bearings. These bearings are available for the cylinder blocks with the main bearing bore that is made larger than the bores' original size. The size that is available has a 0.63 mm (0.025 inch) outside diameter that is larger than the original size bearings.