Contents: Tensioning device ↡ Camshaft Sprocket ↡ Crankshaft sprocket ↡ High pressure fuel pump sprocket ↡ Tensioner guide ↡ Top guide ↡ Bottom guide ↡
Tensioning device
Removal
1. From the right side of the engine, unscrew the tensioner housing (do not unscrew the tensioner plug) from the cylinder head. Remove the sealing ring (See Fig. 8.1 a and 8.1 b).
Fig. 8.1 a Tensioner and guides of the camshaft drive chain
Fig. 8.16 Camshaft timing chain tensioner housing (A). Do not remove plug (B)
Inspection
2. Do not attempt to disassemble the tensioner mechanism. If there is a suspicion of breakage or malfunction, the entire device should be replaced.
Installation
3. Before installing the tensioner, it must be filled with oil as follows.
- a) Place the tensioner with the pusher down in a container with engine oil. The oil level should be above the plug level.
- b) Press the device slowly (a hydraulic press may be required to achieve the required force) 7-10 times until the plunger reaches the stop.
- c) When the tensioner is correctly threaded, it should, when compressed, compress slowly, evenly, with little force.
4. Screw the tensioner into the cylinder head and tighten to the required tightening torque.
Camshaft Sprocket
Removal
5. Remove the accessory drive belt as described in chapter 1B.
6. Remove the camshaft cover as described in paragraph 4.
7. Remove the camshaft timing chain tensioner as described in this paragraph above.
8. If required, remove the self-leveling suspension hydraulic pump from the front of the cylinder head as described in chapter 10. Remove the O-ring and gasket, then remove the bolt and remove the pump drive sleeve from the front of the crankshaft.
9. Make sure that the timing marks on the crankshaft and camshaft are aligned correctly as described in paragraph 3. Apply alignment marks to the camshaft sprocket and chain.
10. After this, you should loosen the camshaft sprocket mounting bolt. At the same time, the camshaft should be locked to prevent it from turning; this can be achieved by inserting a screwdriver into the sprocket hole - be careful not to damage the surrounding parts.
11. Loosen the sprocket mounting bolt and remove the washer.
12. Remove the sprocket from the camshaft, remembering how it is installed.
Inspection
13. Check the wear on the sprocket teeth, each tooth forms a reverse "V". If they are worn, the side of each tooth under tension will be slightly concave when compared to the other side of the tooth (i.e. the teeth will look like a hook). If the teeth are worn, the sprocket should be replaced.
Installation
14. Make sure that the timing marks on the crankshaft and camshaft are fully aligned as described in paragraph 3. If a new sprocket is installed, transfer the alignment mark from the old sprocket to the new one.
15. Place the chain on the sprocket teeth, aligning the marks made on the chain and sprocket before removing the chain.
16. Install the sprocket in its place on the camshaft, making sure it is installed correctly as noted before removal. Also check that the stud on the camshaft flange fits into the corresponding hole in the sprocket.
17. Install the mounting bolt and washer and tighten the bolt to the required torque while holding the sprocket as you did when removing it.
18. If required, install the adjustable suspension hydraulic pump drive sleeve to the front of the cylinder head and tighten the bolt to the specified torque as described in Chapter 10. Install the gasket and O-ring (check and replace with new ones if necessary), then install the hydraulic pump as described in chapter 10.
19. Install the camshaft timing chain tensioner as described earlier in this chapter.
20. Using a socket wrench on the pulley/damper mounting bolt to the crankshaft hub, make a full turn of the crankshaft and check that the timing marks on the crankshaft and camshafts still remain in the position corresponding to piston No.1 reaching TDC, as described in paragraph 3.
Caution: Do not turn the engine by the camshaft sprocket.
(Material taken from a web resource: www.MercedesMan.ru)
21. Install the camshaft cover in accordance with paragraph 4.
22. Install the accessory drive belt as described in chapter 1B.
Crankshaft sprocket
Note: To remove the sprocket you will need the appropriate puller.
Removal
23. Remove the camshaft timing chain cover as described in paragraph 6.
24. Remove the oil pan as described in paragraph 11.
25. Remove the camshaft sprocket as described earlier in this paragraph. Manually lower the camshaft drive chain down until it disengages from the crankshaft sprocket.
26. Remove the oil pump drive chain tensioner guide and spring from the lug on the cylinder block - note the correct position of the spring to reproduce it during installation.
27. Loosen the mounting bolt and remove the drive sprocket together with the chain from the oil pump axle. Remove the washer.
28. Apply alignment marks to the camshaft drive chain and crankshaft sprocket.
29. Using the appropriate puller, remove the sprocket from the front end of the crankshaft. You can remove the sprocket by using two large screwdrivers as levers, positioning them on either side of the sprocket. Remember which way the sprocket should be installed in the correct position.
30. If it is loose, remove the woodruff key.
Inspection
31. Contact paragraph 13.
Installation
32. If required, insert a woodruff key into the end of the crankshaft.
33. If you are installing a new sprocket, transfer the chain alignment mark from the old sprocket to it.
34. Engage the chain with the crankshaft and camshaft sprockets, making sure that the marks made before removing the chain are correctly aligned. Then install the camshaft sprocket in its place as described earlier in this paragraph.
35. Install the oil pump drive sprocket with chain (the convex side of the sprocket should face the pump). After making sure the washer is in place, tighten the mounting bolt to the required tightening torque.
36. Install the oil pump drive target tensioner guide bushing, spring and then guide. Make sure the spring is installed correctly, the same as before removal.
37. Install the oil pan as described in paragraph 11.
38. Install the camshaft timing chain cover as described in paragraph 6.
High pressure fuel pump sprocket
39. The description of this operation is part of chapters 4.
Tensioner guide
Removal
40. Remove the cylinder head as described in paragraph 10.
41. Remove the camshaft timing chain cover as described in paragraph 6.
42. Remove the camshaft timing chain tensioner as described earlier in this paragraph.
43. Remove the tensioner guide from the retainers.
Inspection
44. Check the guide and replace it if it is heavily worn, damaged or cracked.
Installation
45. Insert the tensioner guide into place, making sure it is properly clamped by the clips.
46. Install the camshaft timing chain tensioner as described earlier in this paragraph.
47. Install the camshaft timing chain cover as described in paragraph 6.
48. Install the cylinder head as described in paragraph 10.
Top guide
Note: This operation will require a sliding hammer with the appropriate adapter, as well as sealant, which will be needed to lubricate the guide retaining pin.
Removal
49. Remove the camshaft sprocket as described above in this paragraph.
50. Screw a suitable bolt into one of the studs on which the guide is mounted (access to the studs is from the front of the head block)
51. Hook the adapter onto the screwed-in bolt and use a sliding hammer to remove the stud (See Fig. 8.51 a, b).
Fig. 8.51, a. Components of the upper guide of the camshaft drive chain
Fig. 8.51, b. Using a sliding hammer, remove the camshaft drive chain guide retaining pin
52. Repeat the steps to remove the second pin. Take care to ensure that the guide does not slide down the chain without the pin removed.
53. Remove the guide from the cylinder head.
Inspection
54. Refer to point 44.
Installation
55. Place the guide in place, insert the studs into the holes in the cylinder head and drive them in so that they hold the guide.
56. Apply sealant to the outer collar of both studs where they fit onto the cylinder head and drive them into the cylinder head until they stop.
57. Install the camshaft sprocket as described earlier in this paragraph.
Bottom guide
Removal
58. Remove the camshaft timing chain cover as described in paragraph 6.
59. Remove the camshaft timing chain tensioner as described earlier in this chapter.
60. Remove the guide from the mounting studs.
Inspection
61. Refer to paragraph 44.
Installation
62. Install the guide onto the mounting studs.
63. Install the camshaft timing chain tensioner as described earlier in this chapter.
64. Install the camshaft timing chain cover as described in paragraph 6.