Is it really necessary to change timing belt?

It's important to replace your timing belt at the mileage intervals your vehicle manufacturer recommends. Every manufacturer is different, but typically, it needs to be replaced every 60,000–100,000 miles. ... Because the timing belt is made of rubber, it will wear down over time and eventually break.

How do I know if my Cambelt needs changing?

Visual Check. Another way to check whether your cambelt needs replacing, is to take a look at the belt itself. If it is becoming worn, the belt will appear to look glazed or glossy on the underside. This means the rubber is getting hard and will not provide the flexibility the belt needs.