Contents: Examination ↡ Replacement ↡
Examination
1. Remove the camshaft cover according to paragraph 4.
2. Using a wrench on the pulley/damper mounting bolt to the crankshaft hub, turn the engine so that the chain can be inspected along its entire length on the camshaft sprocket.
3. The chain should be replaced if the sprocket is worn or if the chain is worn (this is determined by too much lateral play of the links and noise during operation). It is wise to replace the chain in any case when the engine is disassembled for a detailed inspection. Note that the rollers on a badly worn chain may have slight dents. To avoid future problems and to be sure of the quality of the chain, replace it.
Replacement
Caution: The chain removal procedure described below will require the use of a portable electric grinder to cut one of the chain links. Make sure you have this tool available, as well as a new chain and connecting link, before you begin.
4. Disconnect the negative battery terminal.
5. If it has not already been removed, remove the camshaft cover as described in paragraph 4.
6. Remove the injectors as described in chapter 4.
7. Remove the radiator fan and shroud as described in chapter 3.
8. Remove the chain tensioner as described in paragraph 8.
9. Cover the camshaft and chain with a clean cleaning cloth, leaving the camshaft sprocket exposed.
10. Using a grinder, grind down the protruding connecting rods on one of the chain links located on the sprocket - being very careful not to damage the sprocket.
11. Pull the link plate off the rods and push the link back behind the chain.
12. Remove the cloth, making sure that no sawdust falls down onto or near the target.
13. Using a new link, connect the end of the new chain to the end of the old chain so that when the engine is turned (clockwise), the new chain will go down, wrap around the sprocket and guides, and emerge on the other side. Insert the connecting link from the back of the sprocket and make sure the link is properly seated. Do not put the connecting plate on the link yet at this stage.
14. Now you need to pass the new chain through the sprockets and guides. During this operation, you need to follow these steps:
- a) Maintain tension on the new chain, ensuring that the links remain engaged with the sprocket, otherwise the valve timing will be lost.
- b) Pull the old chain forward to prevent it from jumping off the crankshaft sprocket.
15. Using a socket wrench that fits the pulley/damper bolt to the crankshaft hub, slowly turn the crankshaft clockwise while following the steps outlined above.
16. When the end of the new chain appears, remove the connecting link (making sure that the new chain is taut and that the remaining links are engaged with the sprocket teeth) and disconnect the new chain from the old one. Remove the old chain.
17. Place the new chain on the camshaft sprocket, then align both ends of the chain with the connecting link by inserting it from the back of the sprocket (see fig. 7.17).
Fig. 7.17 Press in the connecting link (shown by arrow) from the back of the chain
18. Put on the connecting plate and secure it by riveting the end of the connecting rods. There is a special tool for this, but a satisfactory result can be achieved using a hammer and a piece of metal (or with a second hammer), pressed against the back of the chain - great care must be taken not to damage the chain or sprocket.
Tip: Temporarily secure the end of the new chain to the camshaft sprocket by using a piece of wire or a wire tie through the hole in the sprocket and around the chain.
19. Check that the chain link is fastened without burrs or nicks at the connection point.
20. Install the camshaft timing chain tensioner as described in paragraph 8.
21. Crank the engine (clockwise), to bring cylinder #1 to TDC. Make sure the marks on the crankshaft and camshaft are aligned correctly as described in paragraph 3.
22. It may be that the chain has shifted by one tooth on the camshaft sprocket during the last operation. If this has happened, it can be corrected by removing the camshaft sprocket (see paragraph 8) and changing the position of the camshaft and sprocket by one tooth in relation to the chain. At the same time, also check the synchronization of the high-pressure fuel pump, as described in chapter 4.
23. Install the fan with the shroud as described in chapter 3.
24. Install the camshaft cover in accordance with paragraph 4.
25. Connect the negative battery terminal.