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. A6 (4A2, C4)
2. A6 Saloon (4A2, C4)
3. A6 / S6 (4A2, C4)
4. A6 Avant (4A5, C4)
5. A6 / S6 Avant (4A5, C4)
6. 100 Avant (4A5, C4)
7. A8 (4D2, 4D8)
8. A8 Saloon (4D2, 4D8)
9. A8 / S8 (4D2, 4D8)
10. A4 (8D2, B5)
11. A4 Saloon (8D2, B5)
12. A4 / S4 (8D2, B5)
13. A4 Avant (8D5, B5)
14. PASSAT (3B2)
15. PASSAT Saloon (3B2)
16. A6 (4B2, C5)
17. A6 Saloon (4B2, C5)
18. A6 / S6 (4B2, C5)
19. PASSAT Variant (3B5)
20. PASSAT Wagon (3B5)
21. See more in applications

The operation of the timing belt tensioner

The FEBI BILSTEIN 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.