To replace the camshaft drive chain on a vehicle's engine, you will need to have a hand grinder on hand. New camshaft drive chains are supplied with removable locking links provided for their installation. The camshaft chain must be replaced as follows:
- remove all parts that impede access to the camshaft drive chain;
- remove oil spray nozzles (although this will require additional work, the engine will be easier to turn over);
- remove the cylinder head cover;
- remove the chain tensioner (subsection 2.12.1);
- cover the chain case with a piece of rag;
- use a grinder to file down the riveted heads of the chain link pins. Do not break the chain yet;
- attach the new camshaft drive chain to the old chain by removing the worn link from the old chain;
- using a wrench with a replaceable socket head and a ratchet inserted into the crankshaft belt pulley mounting bolt, slowly turn the crankshaft in the working direction of its rotation;
- during the slow rotation of the crankshaft, it is necessary to maintain the old drive chain in a taut position by the free end, while its other end, connected to the new chain, will lead the latter onto the sprockets. Make sure that the chain does not come out of engagement with the camshaft drive sprocket and the crankshaft sprocket;
Figure 98. Installing the connecting link-lock in the drive chain (this operation must be carried out from the side indicated by the arrow)
- as soon as both ends of the new chain are at the top of the camshaft drive sprocket, the old chain is disconnected from the new one, and a removable locking link is inserted into the free holes of the rollers of the new chain from the inside out, as shown in the figure 98. Install new retaining rings on the chain connecting link pins. In this case, both ends of the chain should be temporarily tied with wire to the camshaft drive sprocket so that they do not fly off it into the chain housing;
Figure 33. Location of the camshaft guide pin (top). Location of the timing marks corresponding to the position of the piston of the first cylinder at TDC (bottom): 1 - mark on the camshaft sprocket; 2 - mark on the cover of the first camshaft bearing
- turn the crankshaft until the piston of the first cylinder stops at the TDC position. Then check (on the crankshaft pulley or on the vibration damper), so that in this position of the crankshaft pulley the camshaft marks take the position shown in the figure 33. If this does not happen, then it is necessary to check the camshaft and fuel pump drive mechanism, as described in the relevant subsections;
- the remaining work is carried out in the reverse order of removal.
Note: Please note that drive chains can also be connected using conventional insert links. In this case, the outer plate of the chain must be pressed well against the rollers, and the protruding ends of the link pins must be riveted. This work should be done at a service station. The above description applies to chains with removable link locks.