VALVE GP-MAIN CONTROL 3176907 - Caterpillar

EnginesCaterpillar uses many inspection procedures to make sure the main and connecting rod bearings installed in production engines and available for parts service are bearings of the highest quality. But, it is still possible for you to get damaged bearings. Bearings can be damaged during shipment and storage. It is also possible for bearings to be damaged when they are made and not found during inspection.
Because of this possibility, visually inspect each bearing before installation in an engine.
The list that follows can help during this inspection:
1. Burrs or nicks that cause raised material (material above the normal surface) on the bearing surface, bearing back, chamfer or mating face of the bearing are not acceptable. Do not use these bearings.2. If there is separation of the lead-tin overlay or aluminum layers from the steel back, do not use the bearing.3. Some bearings may have large concentrations of small bumps or blisters on the bearing surface. These blisters cause the bearing surface to feel rough. An easy test can be done to find if a bearing with blisters can be used. Rub (slide) a piece of regular writing paper easily over the bearing surface. If the bearing surface is made smooth, the bearing can be used even if the blisters may still be visible. If the bearing is still rough, do not use it. Do not rub the bearing surface with a file, emery cloth, sandpaper, scotch-brite belt or any material other than regular writing paper.4. Bearings that have stains that can not be felt are acceptable.5. Bearings may have different shades (color concentration) of gray. This is because different corrosion preventives are used on the bearing. The color differences do not indicate a defect and have no effect on bearing performance.6. Bearing halves that are in the same box are not a "matched set" until they have been run in an engine.Bearings that are not acceptable must not be used. Any bearing not acceptable can be returned to the factory.