RING-RETAINING 1T1232 - Caterpillar

Remove & Install Crankshaft Main Bearings
Start By:a. remove oil pump Fluid Spillage ContainmentCare must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to "Tools And Shop Products Guide", NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose fluids according to local regulations and mandates.1. Check the main bearing caps for identification for their location and direction in the block. The caps must be installed in the same location and direction from which they were removed. 2. Remove number 2 through number 6 bearing caps (1). Remove thrust plates from the number 4 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 the crankshaft or cylinder block or both.
3. Remove the upper halves of the main bearings by putting Tool (A) in oil hole (2) in the crankshaft. Turn the crankshaft in the direction which will push the end of the bearing with a tab out first.4. Remove the lower halves of the bearings from the caps. Install the bearings dry when the clearance checks are made. Put clean engine oil on the bearings for final assembly.5. Install the new bearings in the caps.6. Install the upper halves of the bearings in the cylinder block with Tool (A).
Be sure tabs (3) on the back of the bearings fit in the tab slots of the caps and cylinder block. 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 he 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 counter weight 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.
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 reinstating the cap.When using Plastigage, the readings can sometimes be unclear. For example, all parts of