KIT-LIGHT 4744935 - Caterpillar

1. Put the engine in position on tooling (A).If the crankshaft journals and bores for the block and rods were measured at disassembly and found to be within specifications, no further checks are necessary. However, if the serviceman still wants to measure the bearing clearances. Plastigage, tool (C) 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, tool (C) 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 reinstalling 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 to make sure that they are within the specification range. Also, experience has shown that when checking clearances tighter than 0.10 mm (.004") the readings may be low by 0.013 to 0.025 mm (.0005 to .0010"). Out-of-round journals can give faulty readings. Also, journal taper may be indicated when one end of the Plastigage is wider than the other.For complete details concerning measuring bearing clearances, see Engine Bearings And Crankshafts, Form No. SEBD0531. Install the bearings dry when the clearance checks are made. Put clean engine oil on all the bearings for final assembly.
Install the bearings dry when the clearance checks are made. Put clean engine oil on all the bearings for final assembly.
Make sure the upper and lower halves of the main bearings are installed so the bearing tabs fit into the notch in the cylinder block and main bearing caps.
2. If the bearings were removed from the engine, clean the bearing surfaces in the cylinder block and the connecting rods. Install the upper halves of connecting rod bearings (1) and main bearings (2). 3. Heat crankshaft gear (3) to a maximum