BREATHER GP 3920632 - Caterpillar

Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
If the crankshaft has been reground or if the crankshaft has been replaced, the height of the piston above the cylinder block must be inspected. It is necessary to remove the cylinder head in order to inspect the height of the piston above the cylinder block.
Clean the crankshaft and inspect the crankshaft for wear or damage. Refer to Specifications, "Crankshaft" for more information. If necessary, replace the crankshaft or recondition the crankshaft.
If necessary, install the crankshaft gear. Refer to Disassembly and Assembly, "Crankshaft Gear - Remove and Install" for the correct procedure.
If necessary, install a new crankshaft timing ring. Refer to Disassembly and Assembly, "Crankshaft Timing Ring - Remove and Install" for the correct procedure.
Ensure that the parent bores for the bearing shells in the cylinder block are clean. Ensure that the threads for the main bearing bolts in the cylinder block are clean and free from damage.
Clean the main bearing shells and the thrust washers. Inspect the main bearing shells and the thrust washers for wear or damage. If necessary, replace the main bearing shells and the thrust washers. Note: If the main bearing shells are replaced, check whether oversize main bearing shells were previously installed. If the thrust washers are replaced, check whether oversize thrust washers were previously installed.
Illustration 1 g01341389
Install upper main bearing shells (5) to the cylinder block. Ensure that the locating tabs for the upper main bearing shells are seated in the slots in the cylinder block. Note: The upper main bearing shells have a groove and two oil holes.
Lubricate upper main bearing shells (5) with clean engine oil.
Illustration 2 g01333482
Attach Tooling (A) and a suitable lifting device to the crankshaft (4). Lift crankshaft (4) into the cylinder block. The weight of the crankshaft is approximately 61 kg (134.5 lb). Note: Do not damage any of the finished surfaces on the crankshaft. Do not damage the main bearing shells.
Illustration 3 g01341402
Lubricate thrust washers (6) with clean engine oil. Install thrust washers (6) into number six main bearing in the cylinder block. Note: The grooves in the thrust washers must be located against the crankshaft. The thrust washers have a locating tab at one end. Ensure that the locating tabs are correctly seated in the cylinder block.
Illustration 4 g01341324
Install lower main bearing shells (3) into main bearing caps (2). Ensure that the locating tabs for the lower main bearing shells are correctly seated into the slots in the bearing caps. Note: The lower main bearing shells are plain bearings that do not have oil holes.
Lubricate lower main bearing shells (3) and lubricate the journals of crankshaft (4) with clean engine oil. Install main bearing caps (2) to the cylinder block. Note: Ensure the correct location and orientation of main bearing caps (2). The locating tabs for the upper and the lower main bearing shells should be on the same side of the engine.
Illustration 5 g01341327
Lubricate the threads of bolts (1) with clean engine oil. Lubricate the