TUBE ASSEM. 7S3351 - Caterpillar

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 the bearing caps, and the arrows (4) on the bearing caps are toward the front of the cylinder block.
When the bearing clearance is checked and the engine is in a vertical position, such as in the vehicle, the crankshaft will have to be lifted up with a force equal to the weight of the crankshaft and held against the upper halves of the main bearings to get a correct measurement with Plastigage (B). The Plastigage will not hold the weight of the crankshaft and give a correct indication. If the engine is in a horizontal position, such as on an engine stand, it is not necessary to hold the crankshaft up. Do not turn crankshaft when Plastigage is in position to check clearance.
Do not use an impact wrench to tighten the bolts the additional 120° 5° when the bearing clearance is being checked.
8. Install the bearing caps for No. 2 through No. 6 main bearings. Put clean engine oil on the bolts. Install the bolts, and tighten bolts at end with tab first to a torque of 260 14 N m (190 10 lb.ft.). Turn the bolts an extra 120° 5° first at the end opposite of the tab. Remove the bearing caps for No. 2 through No. 6 main bearings. Remove Plastigage (B) from the caps. Check the thickness of Plastigage (B) to find the bearing clearance. The bearing clearance must be 0.091 to 0.185 mm (.0036 to .0073 in.) with new bearings. Maximum clearance with use bearings is 0.25