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. A4 (8E2, B6)
2. A4 / S4 (8E2, B6)
3. A4 Avant (8E5, B6)
4. A4 / S4 Avant (8E5, B6)
5. A3 (8P1)
6. A3 / S3 (8P1)
7. GOLF V (1K1)
8. RABBIT V (1K1)
9. TOURAN (1T1, 1T2)
10. A3 Sportback (8PA)
11. 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.