8. Position the cylinder block with the bottom facing up.
9. Unscrew the bolts and remove the main bearing caps.
10. Remove the "old" bearing shells from the cylinder block and from the main bearing caps, if they are still in their original locations. Wipe the bearing surfaces in the block and caps with a clean, lint-free cloth. These surfaces should be kept spotlessly clean. This is very important for setting the correct radial clearance in the bearings.
Checking radial clearances in main bearings
11. Clean the backs of the new upper main bearing shells (with grooves and lubrication holes) and install each in its proper place in the block. Be careful not to mix them up. Each upper bearing has an oil groove and a lubrication hole
Caution: The oil holes in the cylinder block must be aligned with the oil holes in the upper bearing shells.
If you are working on a V6 engine, the thrust bearings (washers) should be installed in the cover and seat in the block #2. On four-cylinder engines, the thrust bearings (washers) should be installed in the cover #3 (central). Install the thrust washers with the grooved side facing outward. Install the thrust washers so that one set is located in the block and the other set is located in the main bearing cap. Clean the backs of the lower main bearing shells (without grooves) and insert them into the corresponding recesses. Make sure that the protrusion on the bearing shell fits into the recess in the cylinder block or main bearing cap.
Caution: Do not use a hammer when installing the bearing shells into place and do not damage the working surfaces; do not apply grease at this stage.
12. Clean the bearing surfaces in the cylinder block and the crankshaft journals with a clean, lint-free cloth
13. Check or clean the oil holes in the crankshaft, as any dirt present there can only go one way - straight through the new bearings.
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14. After thoroughly cleaning the crankshaft, place it in its proper place in the cylinder block
15. Before final installation of the crankshaft, the radial clearance in the main bearings should be checked.
16. Cut several strands of Plestigage to the appropriate size (from a set for measuring clearances in plain bearings). They should be slightly shorter than the width of the root neck.
17. Install one thread on each main journal of the crankshaft, parallel to the axis of the journal (fig. 11.17).
Row 11.17 Place five Plastigages on the main bearing journal as shown
18. Clean the bearing shell surfaces in the main bearing caps. Hold the shells in place and install the caps onto the crankshaft and cylinder block. Do not displace the Plastigage threads. Make sure the caps are installed with the arrows facing the front edge of the engine.
19. Before installing the bolts, apply clean engine oil to their threads, then tighten the bolts finger tight. Tighten the main bearing cap bolts in two stages in the sequence shown (fig. 11.19, a-c) the prescribed force specified in Specifications at the beginning of this chapter. Do not rotate the crankshaft while performing this operation.
Fig. 11.19, a. Main bearing cap bolt tightening sequence - four-cylinder engines
Ryas. 11.19, b. Main Bearing Cap Bolt Tightening Sequence - V6 Models
Rns. 11.19, v. Tightening sequence of side main bearing cap bolts - V6 models
20. Remove the bolts in the reverse order of tightening and carefully remove the main bearing caps, guiding each one straight up and away from the block. Do not disturb the Plastigage threads or rotate the crankshaft. If the bearing cap does not come off, tap it gently on both sides with a soft-faced hammer to loosen it.
21. Compare the width of the split Plastigage thread with the scale printed on the edge of the plain bearing clearance measuring kit packaging (fig. 11.21). Typical main bearing radial clearance should be in the range of 0.04-0.06 mm. Consult your dealer for the exact main bearing clearance on your specific engine.
Fig. 11.21. Estimate the bearing radial clearance using the scale on the plain bearing clearance measuring kit packaging. Measure on the widest part of the Plastigage and use the correct scale (british and metric scales are available)
22. If the clearance is not within the norm, this may be caused by the incorrect size of the bearing shells (then other inserts will be required). Before deciding whether to use different bearings, make sure there is no dirt or oil between the bearings and the head or cylinder block when the clearance is measured. If one end of the Plastigage is wider than the other, the journal may be tapered. If the clearance still exceeds the specified limit, the bearings should be replaced with undersized bearings.
Caution: When installing a new crankshaft, use a standard size bearing set.
23. Carefully remove any Plastigage residue from the bearing journals and/or shells. Make sure the oil holes are clean. Be very careful not to scratch the bearing, use your fingernail or the edge of a plastic card.
Final installation
24. Carefully remove the crankshaft from the cylinder block.
25. Clean the bearing shell surfaces in the cylinder block, then apply a thin, even coat of molybdenum-based grease or motor oil to each of the bearing running surfaces. Apply grease to the thrust surfaces, as well as to the journal surfaces that mate with the thrust bearing.
26. Clean the crankshaft journals and place the crankshaft in its proper place in the cylinder block.
27. Clean the bearing shell surfaces and apply the same grease to them.
28. Hold the bearing shells in place and install the main bearing caps onto the crankshaft and cylinder block. Correct the bearing caps in place using a brass drift or soft-faced hammer.
29. Apply clean engine oil to the bolt threads, wipe off excess oil, then install the bolts and tighten them finger tight.
30. Tighten the main bearing cap bolts in the sequence shown (fig. 11.19, a or 11.19, b) with a force of 13 or 16 Nm.
31. Use a screwdriver or pry bar to push the crankshaft forward until the thrust bearing is in the desired position. Once the crankshaft has been pulled all the way forward, replace the screwdriver so that pressure remains applied to the crankshaft until all main bearing cap bolts are fully tightened.
32. Tighten the main bearing cap bolts in two stages in the sequence shown (fig. 11.19, a or 11.19, b) with the prescribed force and at a given angle in accordance with Specifications at the beginning of this chapter. On V6 engines, tighten the side bolts last (fig. 11.19, a).
33. Recheck the crankshaft end clearance with a feeler gauge or dial indicator. If the crankshaft thrust surfaces are not worn or damaged and new bearings have been installed on them, the end clearance should be correct.
34. Turn the crankshaft several times by hand to weld it for possible seizure. The turning torque should not exceed 5.6 Nm. If the turning torque is too high, immediately find out and eliminate the cause.
35. Install the new rear cuff (see chapter 2A or 2B).