WINDOW GP-CAB 1270504 - Caterpillar

Start By:a. remove oil pump 1. Check each connecting rod cap for its location on the crankshaft. Each cap (1) must have a number which is the same as the number on the connecting rod. Do not mix bearings.2. Use tool (A) to turn the crankshaft until two of the pistons are at bottom center.3. Remove connecting rod caps (2). Remove the lower bearing from the connecting rod caps.4. Push the connecting rods away from the crankshaft and remove the upper bearings from the connecting rods.
Be careful not to damage the crankshaft journals. Do not turn the crankshaft while any of the connecting rod caps are removed.
Install the connecting rod bearings dry when the clearance checks are made. Put clean engine oil on the connecting rod bearings for final assembly.5. Install the upper half of the rod bearings in the connecting rod.6. Install the lower half of the rod bearing in the connecting rod cap. Make sure Plastigage (4) is in position on the lower bearing.The serviceman must be very careful to use Plastigage, tool (B) 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 that the other.For complete details concerning measuring bearing clearance, see Engine Bearings And Crankshafts, Form No. SEBD0531 Be sure tab (3) on the back of the bearing fits in the groove of the caps and connecting rods.