Belt Tensioner - Mechanical

Accessory Drive

Component Tests

Belt Tensioner - Mechanical

The only mechanical check that needs to be made is a check for tensioner stick, grab or bind.

1. With the engine off, check routing of the accessory drive belt. Refer to the illustrations under Accessory Drive Description and Operation in the Description and Operation.

2. NOTE: The accessory drive belt tensioner spring is very strong and requires substantial force to release.

Using a suitable, commercially available serpentine belt tensioner release tool, release the tension on the belt and detach the accessory drive belt from the tensioner. Carry out the following tests:

- Using the release tool, move the tensioner from its relaxed position, through its full stroke and back to the relaxed position to make sure there is no stick, grab or bind, and to make sure that there is tension on the tensioner spring.

- Rotate the tensioner pulley by hand and check for a binding, contaminated or seized condition.

- Inspect the area surrounding the accessory drive belt tensioner for oil leaks or contamination and repair any leaks.

3. If the accessory drive belt tensioner does not meet the criteria in the previous step, install a new tensioner. If the accessory drive belt tensioner meets the criteria in the previous step, proceed to testing the tensioner dynamically.

4. If the tensioner is saturated with oil and grease internally, install a new tensioner.