A DAYCO brand Tensioner Pulley, timing belt is a part of the timing belt drive, which serves to bypass the belt in a certain place or several places and is a freely rotating pulley of small diameter.

The composition of the roller is small: it is the roller mount, the internal rolling bearing with a protective oil seal, and the working body of the roller itself, which is in contact with the belt.

1. ASTRA G Hatchback (T98)
2. ASTRA Mk IV (G) Coupe (T98)
3. ZAFIRA A MPV (T98)
4. ZAFIRA Mk I (A) (T98)
5. ASTRA Mk IV (G) Convertible (T98)
6. ASTRA Mk IV (G) Hatchback (T98)
7. SPEEDSTER (E01)
8. ASTRA G Estate (T98)
9. ASTRA G Coupe (T98)
10. ASTRA G Convertible (T98)
11. ASTRA H (A04)
12. ASTRA H Estate (A04)
13. ASTRA Mk V (H) (A04)
14. ASTRA H GTC (A04)
15. ZAFIRA / ZAFIRA FAMILY B (A05)
16. ASTRA H TwinTop (A04)
17. ASTRA Mk V (H) Estate (A04)
18. ASTRA Mk V (H) Sport Hatch (A04)
19. ZAFIRA Mk II (B) (A05)
20. ASTRA Mk V (H) TwinTop (A04)
21. See more in applications

The principles of the timing belt tensioner work

Excessive tension leads to intensive wear of the timing parts - pulley bearings (water pump, generator, tensioner, etc.), the belt itself, and others. In addition, a tight belt stretches faster and shortens its service life. Too little preload is fraught with more serious problems - slipping of the belt along the toothed pulleys of the camshafts, which leads to a violation of the valve timing and deterioration of the entire engine.

Therefore, a tensioning device is introduced into the timing drive in the form of rollers of one design or another, which, during engine operation, maintain an optimal belt tension.