MANIFOLD GP-EXHAUST 1408644 - Caterpillar

START BY:a. remove oil pump 1. Check each main bearing cap (2) for its location on the engine. Each cap has an arrow (1) to show the front of the block and a number (3) which gives the location of that cap.2. Remove No. 2 through No. 4 main bearing caps from the engine. Remove the lower bearings from the caps.3. Remove the thrust plate from each side of the No. 3 upper main bearing.4. Turn the crankshaft until tool (A) can be installed in oil hole (4). Turn the crankshaft in the direction which will push the upper main bearing out, tab end first.
If the crankshaft is turned in the wrong direction, the tab of the bearing will be pushed between the crankshaft and the cylinder block. This will cause damage to the crankshaft and block.
Install the connecting rod bearings dry when the clearance checks are made. Put 2P2506 Thread Lubricant on the connecting rod bearings for final assembly.5. Install lower bearings in the bearing caps.6. Install upper bearings in the cylinder block with tool (A). Be sure tab (5) on the back of the bearings fits in the groove of the caps and cylinder block.
When bearing caps are installed, make sure the number on the side of the cap is next to and in alignment with the number on the engine block.
If the serviceman wants to measure the bearing clearances, Plastigage is recommended. Lead wire, shim stock or use of a dial bore gauge can damage the bearing surface.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 must be supported. Use a jack under an adjacent crankshaft counterweight, and hold the crankshaft 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 cap, but do not remove the Plastigage. Measure the width of the Plastigage while it is in the bearing cap or on the crankshaft journal. Do this by using the correct scale on the package. Record the measurements.... Remove the Plastigage before installing the cap.When using Plastigage, the readings can sometimes be unclear. For example, all parts of the Plastigage are not the same width. Measure the major widths