AIR COMPRESSOR GP 7W4020 - Caterpillar

Remove & Install Crankshaft Main Bearings
Start By:a. remove oil pump1. 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 No. 2 through No. 6 bearing caps (1). Remove thrust plates from the No. 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 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.7. Check the bearing clearance with Plastigage (B). Put Plastigage (B) on the bearings. Do not turn the crankshaft when Plastigage (B) is in position.
Be sure the main bearing caps are installed so the numbers on the side of the cylinder block are the same as the numbers on