Removal and installation the timing belt (Opel Astra G)

Timing Belt Replacement

The timing belt must be removed on a cold engine!

Do not turn the engine with the timing belt removed!

On SOHC equipped models, a new camshaft timing gear bolt will be required.

Engine 1.7L SOHC

For 1.7L DOHC diesel engines the procedure is similar to that described for DOHC petrol engines (see Repair procedures for gasoline DOHC engines without removing them from the vehicle).

Removal

See illustration Timing Belt Replacement.

1. Disconnect the negative cable from the battery.

2. Remove the air cleaner with the intake duct and mass air flow (MAF) sensor.

3. Remove the upper timing belt cover [1].

4. Remove the accessory drive belt.

5. Set the parking brake, jack up the front of the vehicle and place it on supports. Remove the right front wheel. If so equipped, remove the crankcase guard.

6. Remove the mounting bolts [2] and remove the crankshaft pulley [3].

7. Support the engine using the KM-6001 device and install the KM-909-B centering tool.


8. Remove the right powertrain suspension support with its bracket.

9. Remove the accessory drive belt tensioner.

10. Remove the timing cover (see Removal and installation the timing belt cover).

11. Turn the crankshaft and bring the engine to a position 90° before the TDC of the end of the compression stroke of the piston of the first cylinder [5].

12. Make sure that the exhaust valve drive cam of the first cylinder is turned with the working protrusion vertically upwards [6].

13. Loosen the fuel injection pump gear mounting bolts [7] and tighten them by hand.

14. Loosen the tensioner bolt [8] and use the Allen key [10] to turn it clockwise until the left stop is in the appropriate position [9].

15. Lightly tighten the tensioner bolt and remove the timing belt. Remove the camshaft gear mounting bolt [11] — the bolt must be replaced without fail.

16. Screw in the new camshaft timing gear mounting bolt and tighten it by hand, making sure that the wheel can turn.

If the belt is in good condition and is subject to further use, mark its original direction of rotation with chalk or paint.

Installation

See illustration Timing Belt Replacement.

1. Make sure that the exhaust valve drive cam of the first cylinder is turned with the working lug upwards [6].

2. Make sure that the engine is in the position 90° before TDC of the end of the compression stroke of the piston of the first cylinder [5].

3. Install the measuring frame KM-661-1 [12] and ensure that its left mounting pins fit into the holes in the timing drive mechanism housing.


4. Install the MKM-571-V dial gauge, resting its plunger against the heel of the cam of the intake valve drive of the first cylinder (second from the front end) [13a].

A nozzle with a flat cylindrical base with a diameter of 10 mm should be placed on the measuring leg. The preload should not exceed 0.50 mm.

5. Zero the gauge, then move the KM-611-1 measuring frame to the left so that the right mounting pins fit into the receiving sockets in the timing drive mechanism housing, and the measuring attachment is in position [13b].

6. Install the KM-661-2 holder on cylinder No.4 [14].

7. Using a wrench, adjust the position of the camshaft so that the dial gauge reading is approximately 0.80 mm [15].

8. Turn the screw [16] to make fine adjustments to the camshaft, ensuring that the meter readings do not go beyond the range 0.60—0.64 mm.

9. Using the key [17], slowly turn the fuel injection pump gear wheel and insert the locking tool KM-6011 [18] into the housing of the latter.

10. Turning the crankshaft clockwise, bring the engine to the TDC position of the end of the compression stroke of the piston of the first cylinder (see Bringing the piston of the first cylinder to the position of the top dead center of the end of the compression stroke (TDC). Make sure that the alignment marks [19] are correctly aligned.

11. Insert the KM-951 locking tool into the flywheel housing [20].

Fixation can be achieved by installing the distribution pin spring [21] on the bolt.

12. Starting from the crankshaft gear and moving counterclockwise, install the timing belt. Make sure that the belt is tensioned in the areas between adjacent wheels.


13. Loosen the tensioner bolt [8].

14. Using the rod wrench [10], turn the tensioner counterclockwise so that the pointer near the right stop takes the required position [22].

15. Tighten the tensioner bolt with force 25 Nm.

16. After locking the camshaft gear, tighten the bolt [11] with force 75 Nm, then pull it first to 69°, then another one 5°.

17. Having locked the fuel injection pump gear, tighten the bolts [7] with force 25 Nm.

18. Remove the locking tool [14].

19. Carefully remove the measuring frame KM-661-1 [12] - try not to displace the dial gauge.

20. Remove the flywheel locking rod [20] and the locking rod [18].

21. Slowly turn the crankshaft two full turns clockwise and bring it to the TDC position at the end of the compression stroke of the piston of the first cylinder, making sure that the alignment marks [19] are correctly aligned.

22. Loosen the tensioner bolt [8] and, turning it clockwise, achieve the required alignment of the indicator [23] - new belt or [24] - used belt.

23. Tighten the tensioner bolt with force 25 Nm.

24. Slowly turn the crankshaft two full turns clockwise and bring it to the TDC position at the end of the compression stroke of the piston of the first cylinder, making sure that the alignment marks [19] are correctly aligned.

25. Check the correct position of the tensioner indicator (see above p.22). If necessary, repeat the belt tension adjustment procedure.

26. Turn the crankshaft two full turns clockwise, make sure that the timing marks [19] are correctly aligned and install the KM-951 timing pin [20] into the flywheel housing.


27. Insert the KM-6011 locking pin into the high-pressure fuel pump [18].

28. Install the KM-661-1 measuring frame [12] and make sure that its mounting pins are in the receiving sockets in the timing drive mechanism housing [13b] — the dial gauge should record the reading 0.55±0.03 mm. If necessary, repeat the installation procedure.

29. Proceeding in the reverse order of dismantling, install the removed components in their places.

30. Tighten the crankshaft pulley mounting bolts [2] with force 20 Nm.

Original source on the website OPELBOOK