Notes:
- The manufacturer recommends checking the belt tension and controlling it during adjustment using a special strain gauge tester. In this regard, there is no data on the force when deflecting a belt branch by a certain size in the technical documentation. In practice, you can approximately estimate the correctness of the belt tension using the "rule of thumb": press on the belt branch with your thumb and determine the deflection using a ruler. According to this universal rule, if the distance between the pulley centers is from 180 to 280 mm, the deflection should be approximately 6 mm.
- There is another way to pre-check the belt tension by twisting its leading branch along the axis. If you can twist the branch more than 90° by hand, the belt is weak.
- These methods can only diagnose excessive belt looseness, so contact a service center for an accurate check and adjustment of the tension.
- The K4M engine is equipped with a timing belt tension roller with automatic adjustment.
Replace the timing belt if, upon inspection, you find:
- traces of oil on any surface of the belt;
- traces of wear on the toothed surface, cracks, cuts, folds and separation of the fabric from the rubber;
- cracks, folds, depressions or bulges on the outer surface of the belt;
- fraying or delamination on the commercial surfaces of the belt.
Warning: If the belt has traces of motor oil on any of its surfaces, it is imperative to replace it, as oil quickly destroys rubber.
The reason for oil getting on the belt (usually this is a leak in the crankshaft and camshaft seals) eliminate immediately.
Note: Carry out the work on an inspection pit, overpass or, if possible, on a lift.
To replace the timing belt and tension roller of the K7J and K7M engines, do the following.
You will need: all the tools necessary to remove the accessory drive pulley and both timing belt covers, as well as a 10 mm spanner, a special key for turning the tension roller, or round-nose pliers with bent jaws.
1. Set the piston of the 1st cylinder to the TDC position of the compression stroke and remove the accessory drive pulley and the lower timing belt cover (see "Setting the piston of the first cylinder to the TDC position of the compression stroke").
2. Remember or mark in any way the position of the tension roller relative to the axis, loosen the tightening of the roller mounting nut...
3. ...and turn the roller clockwise, thereby loosening the tension of the timing belt.
4. After removing the belt from the toothed pulleys of the water pump...
5. ...camshaft...
6. ...crankshaft and tension roller...
7. ... remove the belt from the vehicle.
Helpful Hint: The original belt should have arrows indicating the direction of its movement when the engine is running. If there are no such arrows, and you are not removing the belt for replacement, apply them in any way possible (for example, with a felt-tip pen), to return the belt to its original position.
(The original can be found on the website: «www.RENAULTBOOK.ru»)
8. To replace the tension roller, completely unscrew the nut from its axis...
9. ...and remove the video.
10. Install the new tension roller in the reverse order of removal. The holes for the special key should be facing outward.
Note: The tensioner pulley replacement is shown during the timing belt replacement. However, if necessary, the pulley can be replaced without removing the belt.
11. First install the belt on the toothed pulley of the camshaft, orienting it with arrows B (or with arrows applied by yourself) in the direction of travel when the engine is running and aligning the mark A with the installation mark on the pulley. Then pull the drive branch onto the water pump pulley...
12. ...and the crankshaft pulley, also aligning the mark on the belt with the installation mark on the pulley. After this, install the belt on the tension roller.
13. Tighten the belt by turning the tension roller counterclockwise until the previously applied marks coincide, and tighten the roller mounting nut.
14. Install the accessory drive pulley on the crankshaft and turn the crankshaft by the pulley mounting bolt two turns. Check that the timing marks on the camshaft and crankshaft pulleys match (see Fig. "Setting the piston of the first cylinder to the TDC position of the compression stroke") and belt tension (see the beginning of this subsection).
15. After checking the alignment of the timing marks and the belt tension, remove the accessory drive pulley, and then install all removed components and parts in the reverse order of their removal before replacing the belt.
16. Adjust the tension of the accessory drive belt (see "Checking the tension of the auxiliary drive belt").
To replace the timing belt and tension roller of the K4M engine, do the following.
You will need: all the tools necessary to set the piston of the 1st cylinder to the TDC position of the compression stroke, as well as a 10 mm socket head and a 6 mm Allen key.
1. Set the piston of the 1st cylinder to the TDC position of the compression stroke and remove the accessory drive pulley (see "Setting the piston of the first cylinder to the TDC position of the compression stroke").
2. Unscrew three bolts A and unscrew two nuts B.
3. Remove the upper timing belt cover.
4. Remove the auxiliary drive pulley mounting bolt...
5. ...and remove the pulley.
6. Remove the three bolts securing the lower timing belt cover...
7. ... and remove the lid
8. Secure the tension roller with a 6 mm Allen key and loosen the roller mounting nut.
9. Remove the timing belt.
Helpful advice.
The original belt should have arrows indicating the direction of its movement when the engine is running. If there are no such arrows, and you are not removing the belt for replacement, apply them in any available way (for example, with a felt-tip pen), to return the belt to its original position.
10. Completely unscrew the tension roller mounting nut and remove it.
11. Remove the timing belt idler pulley mounting bolt...
12. ...and remove the roller together with the bolt and washer.
13. Inspect the removed parts, replace worn parts.
14. Install the idler pulley in the reverse order of removal.
15. Install the tension roller in the reverse order of removal, after tightening the tension roller nut to 7 Nm.
Note.
The protrusion on the tension roller should match the groove on the engine.
16. Install the timing belt.
17. Move the movable mark B of the tension roller clockwise 7-8 mm further than the fixed mark A (for clarity, shown on a removed tensioner)...
18. ...using a 6 mm Allen key for this.
19. Install the accessory drive pulley in the reverse order of removal.
20. Remove the camshaft and TDC locks.
21. Turn the crankshaft by the accessory drive pulley bolt six turns.
22. Loosen the tension roller nut no more than one turn, holding the roller with a 6 mm Allen key.
23. Align the movable mark on the tension roller with the fixed mark and tighten the roller nut to a torque of 27 N·m.
24. To check the correct installation of the valve timing, set the piston of the 1st cylinder to the TDC position of the compression stroke (see "Setting the piston of the first cylinder to the TDC position of the compression stroke").
25. Install the removed parts in the reverse order of their removal.
26. Adjust the tension of the accessory drive belt (see "Replacement of auxiliary drive belts").