Usage:
START BY:
a. remove oil pan
1. The main bearing caps are installed with the part number toward the front of the engine. Each cap has a number on the bottom of the cap which is the same as the number on the camshaft side of the cylinder block.
2. Remove the bolts that hold main cap (1). Remove bearing cap (1) and the lower half of the main bearing.
3. Remove the bearing from the cap.
| 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 the oil hole in the crankshaft journal. Install tool (A). Turn the crankshaft in the direction which will push the upper main bearing out tab end first.
5. Install the lower bearing in the bearing cap without oil.
6. Install the upper bearing (the bearing with the oil hole) in the cylinder block with tool (A). Do not put oil on the bearing.
NOTE: Be sure the tab on the back of the bearings fits in the groove of the cap and cylinder block.
The serviceman must be very careful to use Plastigage 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 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 be using the correct scale on the package. Record the measurements.
... Remove the Plastigage before installing 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 make sure that they are within the specification range. Also, experience has shown that when checking clearances tighter than 0.10 mm (.004") the readings may be low by 0.013 to 0.025 mm (.0005 to .0010"). Out-of-round journals can give faulty readings. Also, journal taper may be indicated when one end of the Plastigage is wider than the other.
For complete details concerning measuring bearing clearances, see Engine Bearings And Crankshafts, Form No. SEBD0531.
| NOTICE |
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When the bearing caps are installed, make sure the caps are installed, make sure the caps are installed with the part number toward the front of the engine and the number on the bottom of the cap is the same as the number of the camshaft side of the engine. |
7. Check the bearing clearance with tool (B) as follows:
a. Put tool (B) and cap (1) in position, and install the bolts. Tighten the bolts to a torque of 61 ± 6 N·m (45 ± 4 lb.ft.).
b. Remove the bearing cap, and measure the width of the Plastigage. The main bearing clearance must be 0.086 to 0.185 mm (.0034 to .0073 in.). The maximum main bearing clearance is 0.20 mm (.008 in.).
8. Put 2P2506 Thread Lubricant on the bolt threads. Put clean engine oil on the lower half of the main bearing. Put bearing cap (1) and lower half of main bearing (2) in position on the engine. Install the bolts.
a. Tighten the tab end bolts to 61 ± 6 N·m (45 ± 4 lb.ft.).
b. Tighten the opposite end bolts to 61 ± 6 N·m (45 ± 4 lb.ft.).
c. Turn the opposite end bolts 60 ± 5°.
d. Turn the tab end bolts 60 ± 5°. An impact wrench can be used for the final tightening torque.
9. Do Steps 1 through 9 for the remainder of the bearings.
NOTE: When a replacement of the thrust plates on No. 3 main bearing is made, install the thrust plates with the identification "BLOCK SIDE" next to the block.
10. Check the crankshaft end play with tooling (C). The end play is controlled by the thrust bearing on No. 3 main bearing. The end play with a new bearing must be 0.064 to 0.480 mm (.0025 to .0189 in.). The maximum permissible end play for used bearings is 0.64 mm (.025 in.).