Contents: Removal ↡ Installation ↡ Checking the axial clearance of the…↡ Checking the radial clearance of the…↡
Removal
1. Remove the engine.
2. Remove the cylinder head.
3. Remove the chain drive cover.
4. Remove the crankshaft pulleys.
5. Remove the crankshaft rear cover and oil seal.
6. Remove the pistons.
7. Unscrew the bolts securing the crankshaft main bearing caps 2 and 2a, starting from the front (figure 2.53).
8. Remove crankshaft 20 from the cylinder block.
Figure 2.53. Crankshaft: 2, 2a - Main bearing cap; 3 - Cover fastening bolts; 20 - Crankshaft; 21 - Lower liners (in covers); 22 - Lower axial clearance adjusters (in covers); 23 - Upper axial clearance adjusters (in the cylinder block); 24 - Upper bearings with oil
Installation
9. Installation is carried out in the reverse order of removal. Lubricate the bearings before installation. The oil channels in the axial clearance adjusters 22 and 23 must be installed with the thrust flanges facing forward. The repair dimensions of the crankshaft are given in Table 2.10.
Table 2.10. Crankshaft repair dimensions
| Parameters | Engines 602.984/985 | |
| Main journal diameter, mm | Standard size | 57.950-57.965 |
| 1st repair size | 57.700-57.715 | |
| 2nd rem size | 57.450-57.465 | |
| 3rd rem size | 57.200-57.215 | |
| 4th rem size | 56.950-56.965 | |
| Connecting rod journal diameter, mm | Standard size | 47.950-47.965 |
| 1st repair size | 47.700-47.715 | |
| 2nd rem size | 47.450-47.465 | |
| 3rd rem size | 47.200-47.215 | |
| 4th rem size | 46.950-46.964 | |
| Installation width of main journals, mm | Standard size | 24.500-24.533 |
| 1st repair size | 24.600-24.633 | |
| 2nd rem size | 24.700-24.733 | |
| 3rd rem size | 24.900-24.933 | |
| 4th rem size | 25.000-25.033 | |
| Crankshaft hole diameter, mm | 62.500-62.519 | |
| Width of the hole for the crankshaft with the liners installed, mm | 19.979-20.000 | |
| Permissible deviation of the crankshaft bore from roundness and taper, mm | 0.02 | |
| Clearance in main bearings, mm | Radial (new) | 0.03-0.05 |
| Radial (acceptable) | 0.08 | |
| Axial (new) | 0.10-0.25 | |
| Axial (acceptable) | 0.3 | |
| Crankshaft runout, mm | Radial | 0.020-0.065 |
| Standard crankshaft liners for 58mm diameter bearing caps | Repair diameter (color - blue), mm | 52 |
| Insert thickness, mm | 2.255-2.260 | |
| Repair diameter (color - yellow), mm | 54 | |
| Insert thickness, mm | 2.260-2.265 | |
| Repair diameter (color - red), mm | 56 | |
| Insert thickness, mm | 2.265-2.270 | |
| Repair diameter (color - white), mm | 57 | |
| Insert thickness, mm | 2.270-2.275 | |
| Repair diameter (color - purple), mm | 58 | |
| Insert thickness, mm | 2.275-2.280 | |
Checking the axial clearance of the crankshaft
10. Measure the width of the crankshaft main bearing journal (figure 2.54).
Figure 2.54. Measuring the width of the crankshaft main journal.
11. Determine the thickness of the axial clearance adjuster. The thickness of the axial clearance adjusters varies from 2.15 to 2.40 mm in 0.05 mm increments.
12. Install the axial clearance adjusters (figure 2.55). Oil passages (arrows) must be lubricated and installed forward.
Figure 2.55. Installing axial clearance adjusters.
13. Measure the crankshaft axial clearance and adjust it if necessary (figure 2.56).
Figure 2.56. Measuring the axial clearance of the crankshaft using an indicator.
Checking the radial clearance of the crankshaft
14. Install the main bearing caps. If the cover is installed correctly, the tab (arrow) on the cover should be offset to the left when viewed in the direction of travel (i.e. from the intake manifold side) (figure 2.57).
Figure 2.57. Checking the correct installation of the main bearing caps.
Article was borrowed from the website [MercedesMan.ru]
15. Measure the diameter of the crankshaft bore in the cylinder block (with main bearing caps installed) in directions A, B and C (figure 2.58a,b).
Figure 2.58a. Directions for measuring the diameter of the crankshaft hole.
Figure 2.586. Measuring the diameter of the hole for the crankshaft.
16. Measure the hole diameter in direction A and record it.
For example, 62.51 mm.
17. Remove the main bearing cap.
18. Measure the main bearing journal diameter (figure 2.59).
For example, 57.95 mm.
Figure 2.59. Measuring the main bearing journal diameter.
19. Calculate the gap:
The bore diameter is 62.51 mm - The crankshaft main bearing journal diameter is 57.95 mm = 4.55 mm. Subtract the radial clearance of 0.04 mm from this result (table 2.10) and we get 4.51 mm. Divide this result by 2 and we get the thickness of the liner 2.255 mm.
20. Select an insert of appropriate thickness.
For example, the thickness of the insert is 2.255 mm. According to table 2.19, select the insert by color. In this case, it is a blue insert.
21. Insert the connecting rod bearing shells into the cap and connecting rod and secure them with bolts.
22. Measure the diameter of the lower connecting rod head with bearings (figure 2.60).
Figure 2.60. Measuring the diameter of the lower connecting rod head (with inserts) using the indicator.
23. Measure the diameter of the connecting rod journals and, based on the measured value, determine the radial clearance in the crankshaft bearings (figure 2.61).
Connecting rod lower head diameter (with inserts) - Connecting rod journal diameter = crankshaft radial clearance.
Figure 2.61. Measuring the crankpin diameter.