3126B Marine Engine Caterpillar

Installation Procedure

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NOTICE
Ensure that the crankshaft main bearing tabs engage with the grooves in the block and the crankshaft main bearing cap.

1. Check the condition of the main bearings. Refer to Guideline For Reusable Parts, SEBF8009, "Main and Connecting Rod Bearings" and refer to Guideline For Reusable Parts, SEBV0544, "Engine Bearings and Crankshafts".

Note: The number six main bearing is the thrust bearing.

2. Clean the bearing surfaces in the cylinder block for the main bearings. Apply clean engine oil on the upper main bearing. Do not put engine oil on the back side of the bearing surfaces. Install the upper main bearing in the cylinder block. Ensure that the tab on the back side of the bearing engages with the groove in the cylinder block.

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Illustration 1	g00639918

3. Put clean engine oil on the journals of the crankshaft bearing. Fasten lifting straps and a hoist to crankshaft (1). Carefully install the crankshaft in the cylinder block.

4. Clean the bearing surface of the main bearing caps. Install the lower main bearing in the crankshaft main bearing caps. Ensure that the tab on the back side of the bearing engages with the groove in the main bearing cap. Apply clean engine oil on the lower main bearing. Do not put engine oil on the back side of the bearing surfaces.

5. Install crankshaft main bearing caps with the part numbers toward the right hand side of the cylinder block. Ensure that crankshaft main bearing caps have numbers 1 through 7. The numbers should start at the front of the engine. Place clean engine oil or Molylube on the bolt threads and the washers.

Note: When the bolts for the rear main bearing cap are tightened, slide the main bearing cap as far forward as possible until the cap is against the bolts. Hold the main bearing cap in this position and tighten the bolts.

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Illustration 2	g00609985

6. Install bolts (2) and the washers for main bearing caps (3). Tighten bolts (2) to a torque of 54 ± 7 N·m (40 ± 5 lb ft).

7. Turn bolts (2) for an additional 90 ± 5 degrees (1/4 turn).

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Illustration 3	g00610119

8. Check the end play of crankshaft (1) with Tooling (A). The end play must be 0.07 mm (0.003 inch) to 0.32 mm (0.013 inch).

End By:

1. Install the pistons and connecting rods. Refer to Disassembly and Assembly, "Pistons and Connecting Rods - Install".
2. Install the camshaft idler gear. Refer to Disassembly and Assembly, "Camshaft Idler Gear - Remove and Install".