1. Remove the cambelt cover. This is usually held in place by a few bolts or screws.
2. Locate the timing marks. There are two timing marks, one on the camshaft and one on the crankshaft. The camshaft timing mark is usually a small notch or dot, while the crankshaft timing mark is usually a larger notch or arrow.
3. Align the timing marks. Using a wrench, turn the crankshaft until the timing marks are aligned.
4. Install the cambelt. Wrap the cambelt around the camshaft and crankshaft, making sure that the teeth of the belt are aligned with the teeth on the gears.
5. Tension the cambelt. Use a cambelt tensioner to tension the cambelt until it is snug.
6. Reinstall the cambelt cover. Replace the cambelt cover and secure it with the bolts or screws that you removed in step 1.
Once you have completed these steps, the timing on your Vauxhall Astra 1.7 TDI should be sorted out.
