TUBE AS 1W2031 - Caterpillar

Start By:a. remove piston cooling jetsb. remove oil pan 1. Use tool (A) to turn the engine flywheel to move counterweights (2) in position for the removal of the main bearing caps. If necessary, the counterweights can be removed.2. Remove the four bolts, and remove bearing caps (1) from the crankshaft. 3. Remove lower bearing halves (3) from bearing caps (1). 4. Remove thrust plates (4) from each side of the center main bearing.
If the crankshaft is turned in the wrong direction, the tab of the bearing will be pushed between the crankshaft and cylinder block. This can cause damage to either or both.
5. Install tool (B) in the oil hole in the crankshaft journal, and remove upper main bearing halves (5) as the crankshaft is turned and the bearing is moved out of the cylinder block. On the center main journal that has no oil hole, put a thin piece of soft material that will not damage the crankshaft journal against the end of the bearing, opposite the tab. Hit the bearing with the soft material until the tab of the bearing is free from the cylinder block. Remove the upper half of the main bearing.Install Crankshaft Main Bearings
Make sure the upper and lower halves of bearings are installed so the bearing tabs fit into the notch in cylinder block and bearing caps.
Install the main bearings dry when the clearance checks are made. Put clean engine oil on the main bearings for final assembly. 1. Install tool (B) in the oil hole of the crankshaft. Put the upper bearing half (half with oil hole) in position on the crankshaft. Use tool (A) to turn the engine flywheel and push the bearing half in position with tool (B). 2. Put clean engine oil on thrust plates (1), and install the plates on each side of the center main bearing. 3. Make sure bearing caps (2) are clean, and install lower bearing halves (3) in the caps.The serviceman must be very careful to use Plastigage correctly. The following points must be remembered:Make sure that the backs of the bearings and the bores are clean and dry.Make sure that the bearing locking tabs are properly seated in their slots.The crankshaft must be free of oil where the Plastigage touches it.If the main bearing clearances are checked with the engine upright or on its side, the crankshaft will have to be lifted up with a force equal to the weight of the crankshaft and held against the crown of the bearing. If the crankshaft is not supported, the weight of the crankshaft will cause incorrect readings.Put a piece of Plastigage on the crown of the bearing half that is in the cap. Do not allow the Plastigage to extend over the edge of the bearing.Install the bearing cap using the correct torque-turn specifications. Do not use an impact wrench. Be careful not to dislodge the bearing when the cap is installed.Do not turn the crankshaft with the Plastigage installed.Carefully remove the