Table of contents: XU engine with 8 valves 🠇 XU10 engine with 16 valves 🠇
In many cases, a car enthusiast can use special tools, either borrowing them temporarily or purchasing them for personal use. Below are the main points regarding the use of the tools. The device used to check the tension of the gear belt shows the tension in units of sim (SEEM).
XU engine with 8 valves
1. Install the thrust bolts into the camshaft and crankshaft gears (see illustration)
14.1 Features of installation and tensioning of the toothed belt using special tools on the XU engine with 8 valves. The letters mark the three main stages of the work
a - turning the belt tension roller
b - tightening the nut
c - crankshaft rotation (two full turns)
1 - camshaft drive gear stop bolt
2 - crankshaft timing gear thrust bolt
3 - control and measuring device for measuring the tension of the toothed belt
4 - trunnion (hook) wrench
2. Position the timing belt as required for the given engine type.
3. Remove the thrust bolt from the camshaft gear.
4. Install the timing belt tensioner 4122-T as shown in Figure 14.1.
5. Insert the trunnion key into the holes on the tension roller to turn it.
6. Press the timing belt inwards from the right side (in the direction of the arrow, see the dotted line in Illustration 14.1).
7. Turn the timing belt tension roller a using a cam key in the direction of the arrow to the left so that the reading on the control and measuring instrument is 30±2 for XU7 engines or 44±2 for XU10 engines.
8. Tighten bolt b to 20 Nm.
9. Remove the thrust bolt from the crankshaft timing gear, remove the control instrument and the trunnion wrench.
10. Turn the crankshaft two full revolutions (four engine revolutions). Reinsert the thrust bolt into the hole on the crankshaft gear and reinstall the gauge.
12. Make sure the instrument shows the timing belt tension equal to 44±2. This value applies to all 8-valve engines. In this case, all the instruments can be removed and the engine assembled. If the reading on the timing belt tension measuring device does not correspond to the specified value, then all work must be repeated from the beginning.
XU10 engine with 16 valves
13. Install the thrust bolts into the holes of the camshaft and crankshaft gears as shown in Illustration 14.13.
14.13 Features of installation and tensioning of the toothed belt using special tools on the XU engine with 16 valves
1 - camshaft drive gear mounting bolt
2 - camshaft gear thrust bolt
3 - timing belt tension roller mounting bolt
4 - toothed belt tension roller
5 - crankshaft timing gear thrust bolt
6 - camshaft drive gear mounting bolt
7 - camshaft gear thrust bolt
8 - toothed belt
9 - control and measuring device
14. Install the timing belt in the order given above (see illustration 13.48).
15. Release the timing belt tension rollers so that they fit snugly against the belt.
16. Install a timing belt tension gauge as shown in Illustration 14.13.
17. Turn the toothed belt tension roller 3 to the left to ensure that the belt is tensioned to a torque of 55 sim, as recorded by the control and measuring instrument (see illustration 14.13). A square key is used to turn the roller.
18. Tighten bolt 3 of the timing belt tension roller to a torque of 20 Nm, without allowing the roller itself to turn.
19. Tighten the camshaft gear mounting bolts to a torque of 50 Nm. While doing this, hold the gears securely to prevent them from turning.
20. Remove the control instrument and take out the stop bolts.
21. Turn the crankshaft two full revolutions (four engine revolutions) and install the crankshaft timing gear thrust bolt in place. If the stop bolt cannot be properly installed after turning the crankshaft, turn the engine two more revolutions. Do not rotate the crankshaft in the opposite direction under any circumstances.
22. Reinstall the timing belt tension gauge and ensure that it reads 35 psi. If so, the belt is installed correctly.
23. Tighten bolt 7 to 20 Nm and the camshaft gear mounting bolts to 75 Nm. If the instrument shows a different value, all work must be performed from the beginning. At the same time, reinstall the stop bolts into the holes on the camshaft and crankshaft gears so that they do not turn.