1 — an asterisk of a gear drive belt of a camshaft;
2 - Tension roller;
3 - Coolant pump drive pulley.
The picture shows the timing belt of a 1.8-litre petrol engine. To check the tension of the belt, press on it (see table) or try to twist it around its axis. If it can be twisted around its axis by 90°, the belt must be replaced or its tension checked with a measuring device.
To check and adjust the tension of the toothed drive belt in Renault workshops, a special control and measuring device El 346-04 is used. When checking, the pusher of the device presses the belt with a force directed between the two toothed belt pulleys. The deflection of the belt is then accurately measured. This device is also used to control and adjust the tension of the V-belt. The belt must have the following parameters:
Engine | engine's type | Place of measurement | Set value | Pressure |
1.7-/1.8 l 16 valve Diesel | F3N / F3P F7P F8Q | Between idler pulley and intermediate shaft sprocket Between idler pulley and intermediate shaft sprocket Between idler pulley and intermediate shaft sprocket | 7.0 0.5 mm 3.0 0.5 mm 7.5 0.5 mm | 30 N 100 N 30 N |
1. Remove the toothed belt guard.
2. 1.7-/1.8-liter engine and diesel: at the correct tension under finger pressure (30 N) in the place between the tension roller and the intermediate shaft pulley, the toothed belt should not bend more than 8 mm.
3. 16-valve engine: at the right tension under strong finger pressure (about 100 N) in the place between the tension roller and the intermediate shaft pulley, the belt should bend no more than 4 mm.
4. You can also try to twist the belt around its axis. It should not twist more than 90°.
5. If in doubt, repeat the test by turning the crankshaft one revolution.
6. Tension the belt again.
Belt tension
1. To tighten the toothed drive belt, fix the crankshaft (to do this, turn on 4th or 5th gear and put the car on the parking brake).
2. Turn off a counternut of a tension roller. Hold the tension roller with a wrench.
3. In order to install the tensioner in the rear part of the toothed belt housing, screw an M 6 bolt about 45 mm long into the thread provided for this opposite the tensioner mounting. After tensioning the belt, unscrew the bolt.
4. Turn the engine 2 turns (pay attention to the direction of rotation!).
5. Check the belt tension again and repeat the adjustment process if necessary.
6. Tighten the locknut to 50 Nm.
7. Establish a casing of a gear drive belt.
8. If possible, check the belt tension and injection timing of the high pressure fuel pump (diesel) in a car workshop.
9. Replace toothed drive belt as needed.
Note. Recommendation: the lock nut must be tightened to the specified torque of 50 Nm, as when the lock nut is loosened, the belt may jump over, causing serious damage to the engine. Therefore, apply an agent to the nut to prevent self-unscrewing.
Do not overtighten the belt to avoid overloading it and the bearing.
In the figure, the arrows indicate the places where the measuring device is used to control the tension of the toothed drive belt.
1 - 1.7-/1.8-liter engine; 2 - diesel; 3 - 16-valve engine.
The toothed drive belt tension must be checked between the tension roller and the intermediate shaft toothed belt pulley.
Toothed drive belt (the figure shows the replacement of the belt on a diesel) put on against the direction of movement in the following order «1» (crankshaft pulley), «2» (high pressure fuel pump pulley), «3» (camshaft pulley) And «4» (intermediate shaft pulley). In this case, the marks on the engine, pulleys and timing belt must match. Marking «IN» is placed on the Bosch high pressure fuel pump pulley, and the marking «R» put for CAV-Roto. Appropriate labeling must be used depending on the pump installed. On a 1.8-liter engine, a toothed belt after the guide roller (6) passes immediately through the camshaft pulley; on a 16-valve engine, the belt after the idler pulley passes first through the intake camshaft pulley and then through the exhaust camshaft pulley.