A SWAG 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. AX (ZA-_)
2. BX (XB-_)
3. BX Break (XB-_)
4. C15 Van (VD_)
5. XM (Y3)
6. XM Break (Y3)
7. XM Estate (Y3)
8. ZX (N2)
9. XANTIA (X1_, X2_)
10. 205 II (20A/C)
11. 205 Mk II (20A/C)
12. 205 I Convertible (741B, 20D)
13. 205 � Convertible (741B, 20D)
14. 309 I (10C, 10A)
15. 309 � (10C, 10A)
16. 309 II (3C, 3A)
17. 309 Mk II (3C, 3A)
18. 405 I (15B)
19. 405 I Saloon (15B)
20. 405 � (15B)
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.