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. COROLLA Liftback (_E8_)
2. COROLLA (_E8_)
3. COROLLA Saloon (_E8_)
4. COROLLA (_E9_)
5. COROLLA Saloon (_E9_)
6. COROLLA Liftback (_E9_)
7. COROLLA Compact (_E9_)
8. COROLLA Station Wagon (_E9_)
9. CARINA II Saloon (_T15_)
10. CARINA Mk II Saloon (_T15_)
11. CARINA II Saloon (_T17_)
12. CARINA Mk II Saloon (_T17_)
13. CARINA II (_T17_)
14. CARINA II Liftback (_T17_)
15. CARINA Mk II (_T17_)
16. CARINA II Estate (_T17_)
17. CARINA Mk II Estate (_T17_)
18. TERCEL (_L1_, _L2_)
19. TERCEL (AL2_)
20. CELICA Coupe (_T18_)
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.