Tensioner and sprockets — removal and installation (Opel Astra G)

Camshaft sprocket

1. Remove the camshaft drive belt.

2. Set the piston of the 1st cylinder to TDC of the compression stroke and turn the crankshaft 60° counterclockwise.

3. Secure the camshaft sprocket with a special key by the holes (see photo) and unscrew the bolt. Remove the sprocket. Note that the exhaust camshaft sprocket on 2.0L engines is marked EXHAUST (this sprocket also has 4 spokes), on other engines this sprocket can be distinguished by the teeth of the camshaft angle sensor.

Note! The camshaft can also be held by the flats with a wrench, for which you should remove the cylinder head cover (see photo).

Installation

4. Check the condition of the oil seal and replace if necessary.

(Text copied from an online resource OpelBook.ru)

5. Install the sprocket in place so that the pin on the end of the camshaft fits into the hole on the sprocket (see photo). Fix the camshaft (or an asterisk) and tighten the bolt in 3 stages (see Technical data).





6. Turn the crankshaft 60° clockwise until the marks align. Install the camshaft belt (see photo).



7. Install the remaining removed parts.

Crankshaft sprocket

All engines except 2.0L

8. Remove the timing belt, remove the sprocket from the crankshaft nose. When installing the sprocket, orient it so that the mark faces outward (see photo).



2.0L Engines

9. Remove the timing belt.

10. Secure the crankshaft from turning and unscrew the bolt. To secure the crankshaft, engage the highest gear and ask an assistant to depress the brake pedal. On models with an automatic transmission, unscrew one of the drive disk mounting bolts and secure the disk relative to the crankcase using a bar and 2 bolts. If the bolt unscrews on a removed engine, secure the flywheel with a tool by the toothed ring.

11. Remove the sprocket from the crankshaft nose.

12. Installation is performed in the reverse order. Install the sprocket so that the mark faces outward. Secure the crankshaft from turning and tighten the bolt in 2 stages (see Technical data). Install the camshaft belt.

Timing Belt Tensioner

13. Remove the camshaft drive belt.

14. Loosen the mounting bolt and remove the tensioner.

15. Installation is performed in the reverse order. Install the tensioner so that the tooth on the plate enters the hole in the oil pump housing, then turn the tensioner clockwise until it stops - the tensioner roller should move away from the belt as far as possible.(see photo). Tighten the tensioner bolt to the specified torque.

Intermediate rollers

16. Remove the camshaft belt, unscrew the bolt (or bolts) and remove the roller (see photo).