Contents: Removal ↡ Installation ↡
Removal
1. Remove the engine.
2. Remove the pistons.
3. Remove the oil pump.
4. Remove the timing belt cover.
5. Remove toothed pulley 8 of the crankshaft (figure 3.19a).
6. Remove the main bearing caps 5 and 6. The axial clearance adjusters are installed on the cap of the fifth main bearing 6 (figure 3.19b).
7. Remove the lower liners 3.
8. Remove crankshaft 1 from the cylinder block.
9. Remove the upper liners 2.
10. Check the main bearing shells 2 for wear.
11. Wipe the main engine oil line.
12. Measure the main dimensions of the crankshaft and, if necessary, carry out repairs. The crankshaft dimensions are given in Table 3.7.
Installation
13. Install crankshaft 1.
14. Check bolts 7 securing the main bearing caps.
Thread diameter: M14. New bolt length: 114.0 mm. Allowable length: 116.0 mm.
15. Install the main bearing caps 5.
16. Determine the thickness of the axial clearance adjuster and install cover 6.
17. Install toothed pulley 8 of the crankshaft.
18. Install the pistons and connecting rods.
19. Install the oil pump.
20. Install the timing belt cover.
21. Replace the oil filter element.
22. Replace the oil cooler.
23. Install the engine.
Figure 3.19a. Crankshaft: 1 - Crankshaft; 2 - Upper liners; 3 - Lower liners; 4 - Axial clearance adjusters; 5, 6 - Main bearing caps; 7 - Main bearing cap mounting bolts; 8 - Crankshaft toothed pulley; 9 - Finger.
Figure 3.19b. Crankshaft: 1 - Crankshaft; 2 - Upper liners; 3 - Lower liners; 4 - Axial clearance adjusters; 5,6- Main bearing caps; 7 - Length of main bearing cap bolt; 8 - Crankshaft toothed pulley; 10 - Camshaft pulley; 11 - Indicator; 12 - Support.
Table 3.7. Crankshaft dimensions
| Parameters | Engines 904 | |
| Main bearing journal width, mm | Standard | 31.000-31.062 |
| Rem. size -0.3 | 31.300-31.362 | |
| Rem. size -0.5 | 31.500-31.562 | |
| Axial clearance, mm | 0.16-0.38 | |
| Thickness of the axial clearance adjuster, mm | Standard | 3.240-3.300 |
| Rem. size 0.3 | 3.540-3.600 | |
| Rem. size 0.5 | 3.740-3.800 | |
| Crankshaft journal diameter, mm | Standard | 85.990-86.010 |
| Rem. size -0.1 | 85.890-85.910 | |
| Rem. size -0.25 | 85.740-85.760 | |
| Rem. size -0.5 | 85.490-85.510 | |
| Rem. size -0.75 | 85.240-85.260 | |
| Rem. size -1.0 | 84.990-85.010 | |
| Inner diameter of the hole for the crankshaft main bearing journal, mm | Standard | 86.066-86.108 |
| Rem. size 0.1 | 85.966-86.008 | |
| Rem. size 0.25 | 85.816-85.858 | |
| Rem. size 0.5 | 85.566-85.608 | |
| Rem. size 0.75 | 85.316-85.358 | |
| Rem. size 1.0 | 85.066-85.108 | |
| Main bearing journal width, mm | 31.0-31.2 | |
| Permissible ovality of crankshaft journals, mm | 0.005 | |
| Permissible taper, mm | Neck of the root | 0.005 |
| Crank pin | 0.005 | |
| Hardness of crankshaft journals, HRC | 52 | |
| Convex | Neck of the root | 0.000-0.004 |
| Crank pin | 0.000-0.004 | |
[Text republished from the website: mercedesman]