Usage:
Start By:
a. remove engine 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 "Tools And Shop Products Guide", NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose of fluids according to local regulations and mandates.
1. Check each main bearing cap (2) for its location on the engine. Each cap has an arrow (1) which points to the front of the block and a number (3) which gives the location of that cap.
2. Remove No.2 through No.6 main bearing caps from the 3412 Engine and remove No.2 through No.4 main bearing caps from the 3408 Engine. Remove the lower bearings from the caps.
3. Remove the thrust plates from each side of the No.4 main bearing on the 3412 Engine. Remove the thrust plates from each side of the No.3 main bearing on the 3408 Engine.
| 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 the cylinder block. This will cause damage to the crankshaft and block. |
4. Turn the crankshaft until Tool (A) can be installed in oil hole (4). Turn the crankshaft in the direction which will push the upper main bearing out, tab end first.
| NOTICE |
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Make sure the upper and lower halves of bearings are installed so bearing tabs (5) fit into the notch in cylinder block and bearing caps. |
NOTE: Do not put oil on parts until the bearing clearance has been checked.
5. Use Tool (A) to install the upper bearings in the block. Make sure that the end of the bearing without the tab goes into the engine block first.
6. Install the lower bearings in the bearing cap.
NOTE: When the bearing clearance is checked and the engine is in a vertical position, the crankshaft will have to be lifted up 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, it is not necessary to hold the crankshaft up. While checking the bearing clearance, do not turn the crankshaft with the Plastigage in position.
7. Check the bearing clearance with Plastigage (B) as follows:
a. Put a piece of the Plastigage on the surface of the lower bearing half.
b. Install the main bearing caps with arrow (6) toward the front of the cylinder block. Each cap has a number (7) on the bottom surface and must be installed in the same position as the correct number on the left side of the cylinder block.
c. Put clean oil on the threads of the cap bolts. Install the cap bolts finger tight.
d. Tighten the bolts on the tab end of the caps first to a torque of 258 ± 14 N·m (190 ± 10 lb ft).
e. Tighten the bolts on the other end of the caps to a torque of 258 ± 14 N·m (190 ± 10 lb ft).
| NOTICE |
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Do not use an impact wrench to tighten the bolts the additional 120 degrees. |
f. Put a mark across the bolt head and cap. Tighten the bolts opposite the tab end 120 degrees. Tighten the bolts on the tab end of the cap 120 degrees.
8. Remove the caps and measure the Plastigage. The clearance for new bearings must be 0.091 to 0.186 mm (.0036 to .0073 in). The maximum clearance for used bearings is 0.25 mm (.010 in).
9. Install a thrust plate (8) (see illustration D16249) on each side of the No.4 for the 3412 Engine and No.3 for the 3408 Engine upper bearing. Install the thrust plates with the side marked "Block Side" toward the cylinder block.
10. Put clean oil on the lower bearings. Repeat Steps 7b through 7f to install the bearing caps.
11. Remove the No.1 and No.7 bearing caps on the 3412 Engine. Remove the No.1 and No.5 bearing caps on the 3408 Engine. Repeat Steps 4 through 8 and Step 10 for these bearings.
12. Check the crankshaft end play with Tool (C). The end play is controlled by the thrust plates on the center main bearing. Make sure the dial indicator is against a machined surface. End play for new thrust plates must be 0.13 to 0.50 mm (.005 to .020 in). The maximum end play with used thrust plates is 0.89 mm (.035 in).
End By:
a. install engine oil pump