How to adjust belt tension

How to adjust the belt tension is actually quite important to know for every car users to anticipate the belt tension condition, which will cause a noise sound or causing the other components such as the alternator or power steering pump not to work properly.

Loose belt tension will generally result in a very uncomfortable squeaking noise. If you continue to let it sit, the belt itself may break due to slippage and heat.

There are 3 models of belt tension adjustment, such as an automatic adjustment, using the clamp bolt model adjustment, and the adjusting bolt model. We do not explain for the automatic belt tension model's adjustment because it does not need adjustment.

Here is how to adjust the belt tension using the clamp bolt and adjusting bolt model, see the steps below.

1. For the clamp bolt model (brace bolt)

This brace bolt adjustment is a belt tension adjustment where the adjustment bolt clamps only to the adjustment frame. Generally, the bolt is only one and is directly installed between the adjustment frame and the alternator body.

Pay attention to the belt tension image whose adjustment model uses a brace bolt as below.

How to adjust the car belt tension using the clamp bolt model

Here is how to adjust the car belt tension using the clamp bolt model

1. Loosen the support bolt at the bottom of the alternator
2. Loosen the brace bolt at the top of the alternator
3. Insert a long screwdriver or small crowbar between the alternator and the engine, then press it downwards to tighten the belt tension. Pay attention as shown below
   
4. Tighten the clamp bolt
5. Measure belt tension and adjust it according to tightening specifications
6. Retighten the support bolts and clamp bolts.

2. For the adjusting bolt model

The adjusting bolt model is a belt tension adjustment where there are a lock bolt and the adjusting bolt at the top of the alternator. Whereas at the bottom of the alternator, there is still a support bolt. Note the belt tension adjustment model that uses an adjusting bolt, as shown below.

How to adjust the car belt tension using the adjusting bolt model

Here is how to adjust the car belt tension using the adjusting bolt model

1. Loosen the support bolt at the bottom of the alternator
2. Loosen the lock bolt
3. Turn the adjusting bolt towards the right to tighten, or to the left to loosen.
4. Measure the belt tension, and adjust it according to the vehicle specifications.
5. Retighten the lock bolt.
6. Retighten the support bolts

Also Read:

• Timing belt noise causes and solutions
• How to make serpentine belt stop squeaking

How to check the belt tension

To make it easier to adjust the car belt tension in this article, the following is how to check the car belt tension. Please, always refer to your car service manual. Consider an example of how to check the belt tension of a car in the image below.

Use a tool called a spring scale, then press with a load of 10 kg. A good pressure specification will indicate a belt tension deflection distance of 0.3-0.4 inch. If you do not have a spring scale, you can press it by hand and expect a pressure of about 10 kg, then pay attention to the belt tension's deflection distance. Try not to exceed the 0.3-0.4 inch distance.