Usage:
Start By:
a. remove oil pump
Fluid Spillage Containment
Care 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 the 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 No. 2 through No. 6 bearing caps (1). Remove thrust plates from the No. 4 main bearing.
| NOTICE |
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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.
NOTE: 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).
NOTE: 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:
-Ensure that the backs of the bearings and the bores are clean and dry.
-Ensure 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 ensure that they are within the specification range. Also, experience has shown that when checking clearances tighter than 0.10 mm (.004 in) the readings may be low by 0.013 to 0.025 mm (.0005 to .0010 in). 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.
Refer to SEBD0531, "Engine Bearings and Crankshafts" for complete details concerning measuring bearing clearances.
7. Check the bearing clearance with Plastigage (B). Put Plastigage (B) on the bearings.
| NOTICE |
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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. |
8. Install the bearing caps for No. 2 through No. 6 main bearings. Put 4C-5593 Anti-Seize Compound on the bolts. Install the bolts. Starting with the tab end of the bearing cap first, tighten each bolt in bearing caps No. (2) through No. (6) to a torque of 260 ± 14 N·m (190 ± 10 lb ft). Put a mark on each bolt and bearing cap. Start with the bolt way from (opposite) the tab end of the bearing cap, and again tighten each bolt an additional 120 ± 5 degrees.
9. Remove main bearing caps No. 2 through No. 6. Remove Plastigage (B) from the caps. Measure the thickness of Plastigage (B). This measurement is the bearing clearance. The bearing clearance must be 0.091 to 0.185 mm (.0036 to .0073 in) with new bearings. Maximum clearance with used bearings is 0.25 mm (.010 in)
10. Put clean engine oil on the bolts and threads. Install the bolts in main bearing caps No. 2 through No. 6. Starting with the tab end of the bearing cap first, tighten each bolt bearing caps No. (2) through No. (6) to a torque of 260 ± 14 N·m (190 ± 10 lb ft). Put a mark on each bolt and bearing cap. Start with the bolt away from (opposite) the tab end of the bearing cap, and again tighten each bolt an additional 120 ± 5 degrees.
11. Remove The No. 1 and No. 7 main bearings caps. Repeat Steps 3 through 10 for the No. 1 and No. 7 main bearing caps.
12. Install the thrust plates for the No. 4 main bearing.
NOTE: Install the thrust plates with the identification "BLOCK SIDE" toward the cylinder block.
13. Check the end play of the crankshaft with Tooling (C). Be sure the tip of the dial indicator is positioned against a machined surface. The end play is controlled by the thrust plates of No. 4 (center) main bearing. The end play with new thrust plates must be 0.15 to 0.51 mm (.006 to .020 in). The maximum permissible end play with used thrust plates is 0.89 mm (.035 in).
End By:
a. install oil pump