The timing belt tensioner is a load-bearing pulley located on an adjustable axle. Its main function is belt tension; additional functions are to damp drive vibrations and increase the angle of the camshaft pulley wrap.

1. A4 (8D2, B5)
2. A4 Saloon (8D2, B5)
3. A4 / S4 (8D2, B5)
4. A4 Avant (8D5, B5)
5. A3 (8L1)
6. A3 / S3 (8L1)
7. A6 (4B2, C5)
8. A6 Saloon (4B2, C5)
9. A6 / S6 (4B2, C5)
10. OCTAVIA I (1U2)
11. GOLF IV (1J1)
12. GOLF IV (1J1, 9B1)
13. GOLF Mk IV (1J1)
14. A6 Avant (4B5, C5)
15. A6 / S6 Avant (4B5, C5)
16. SHARAN (7M8, 7M9, 7M6)
17. ALHAMBRA (7V8, 7V9)
18. OCTAVIA I Combi (1U5)
19. TT (8N3)
20. TOLEDO II (1M2)
21. See more in applications

The operation of the timing belt tensioner

The AIC brand Tensioner, timing belt is a bearing with a pulley on the outer cage. Depending on the design, the tensioning mechanism can be made in the form of an eccentric pressed into the inner bearing race, or placed on a separate bracket. The bearing cage is packed with grease and covered with a lip. You can order an automatic tensioner, it is a little more complicated, but the roller itself has no fundamental differences.

Timing belt tension is designed for a specific force and must be consistent. Selecting a timing belt tensioner pulley that is too loose can cause the belt to slip through the timing belt teeth. This is unacceptable, since it will lead to a shift in the phases of the valve operation relative to the movement of the pistons.