Auto Service World
Feature   March 1, 2012   by Nestor Gula

It’s not just the belt

All components should be replaced when changing a timing belt

One can argue all day and night about what is the most overworked component of a vehicle. Few will mention the timing belt. Here is a little thin strip of rubber compound that is whizzing about at high speed making sure everything in the engine works.

To be fair, timing belt failures are not that common. But that is just a testament to the high-quality of engineering that has gone into making them.

The old way of testing them by visual inspection is now long-gone. Because of how today’s belts are engineered and the new kinds of materials used in their making, manufacturers have instigated interval life spans for when it is time to replace the belts. “Timing belts are typically replaced at pre-set intervals according to the vehicle manufacturer’s recommendations,” said David Hirschhorn, director, brand management for CRP Industries Inc. “We do not approve of any timing belt testing methods used because in order to perform any tests on the belt it would have to be removed to assess the condition of the materials and the teeth. If a technician is going to take the time to investigate the condition of the belt they are better off just changing it. If the belt has been on the vehicle for an unknown time period or an unknown mileage interval, we recommend having it changed to avoid costly repair bills that a broken timing belt could cause.”

There is no question, when a vehicle reaches a certain mileage, the belt should be replaced. The range for the interval on vehicles ranges from 60,000 to 100,000 kilometres but you should always check the specific requirements for each individual vehicle as a matter of course.

Replacing the timing belt is not a simple job anymore. It is not like the old days when you could just leverage the tensioning pulley to one side, slip the old one off and slip the new one on. As with everything else in the world, things have gotten more complicated, complex and involved. Replacing a timing belt can be an arduous and lengthy journey for many vehicles.

It makes sense then, while you are rummaging in the front end of the engine to do whatever other work is needed there. Replacing the other pulleys, the tensioner and water pump seems like a logical thing to do. “From my experience, if a timing belt needs replacement because it is at the end of its interval life, the components need replacement as well,” said Marc Therrien, an account executive with Veyance Technologies Canada, Inc. “The thought process is that if you are replacing a timing belt you should replace the components as well because it will reduce chances of a comeback because if a belt is replaced and one of the components seizes at the end of its life and then causes damage to the engine This is critical with interference engines because there could be valve damage when the piston hits the valve.”

“There are still many vehicles that have interference engines and if the timing belt should fail on an interference engine that could result in catastrophic engine damage where you would have valve-on-valve damage and a major engine job on your hands. It could result in a complete engine replacement,” said Randy Chupka, director of marketing with Gates Canada Inc. “Do not recommend just replacing the timing belt. When replacing just the timing belt, the belt will be fine but one of the components within the system might fail and that timing belt job that you just did, you will have to redo it because you have to replace the failed component. Our approach is that the shops do the complete job and replacing the belt and all the components that are part of the system. The good shops are already doing the complete jobs. What the timing belt kit does is make it easier for the shops to source all the products they need for a complete timing belt job.”

Timing belt kits are all designed for the specific cars and will give you everything you need to replace all the components. Although you can still buy the individual belts, no manufacturer recommends this. “Kits are very popular and what makes them important for the shop is that it allows the shop to do the timing belt job right the first time,” said Chupka. “In the past we just sold timing belts and the shops had to source all the other individual components spending probably up to an hour tracking down all the parts. It is a huge time saver for the shops wanting to do a complete job – it is just one call to their local parts supply store.

All kits from the major manufacturers contain the timing belt or multiple timing belts as is necessary, the tensioners and timing pulleys, idler pulleys and anything related with that complete timing belt job. Some will also have a water pump if the water pump is driven by the timing belt. Engines that have gear driven water pumps will not have a water pump included. “More than five years ago, a timing belt kit in our industry typically included the timing belt as well as all the idlers and tensioner bearings needed for the application,” said CRP’s Hirschhorn. “They now have kits with water pumps and hydraulic dampers, cam and balance shaft seals depending on vehicle and application. All the added components in these upgraded kits are often replaced with a timing belt service, making sense for service stations to use a kit that includes all the necessary components to complete the job.”

Depending on the make, the kit can cost up to 500 dollars if it is complex and has a water pump. “A lot of shops will recommend that the complete components be replaced because the consumer is already spending the labour dollars to get to the timing components,” said Therrien. “The shop has gone through the labour of getting into the components, instead of just replacing the belt a lot of times the complete components will be replaced. We are seeing more and more shops changing the complete components once they get into there.”

“Timing belt components are specific to each engine so the time needed to install a kit varies greatly,” said Hirschhorn. “On simple engines the kit might be able to be installed in less than an hour, but on some vehicles with more complex systems it could take as much as four hours or more. Some engines use timing belt components that require critical steps during the installation process which in turn can cause issues for the installer.” All manufacturers have detailed instructions on properly installing all the components to ensure there are no comebacks on these critical repairs.

At the end of the day the shop might have to be explaining that this regular maintenance procedure, recommended by the vehicle’s manufacturer might cost the customer up to one-thousand dollars. This is a big bite in the wallet. “If the service station quotes the customer a large dollar amount for the job without explaining everything involved they’re fighting a losing battle,” said Hirschhorn. “But, if that service station educates the vehicle owner so that they understand the steps required and all the components that need to be replaced, they are more likely to get approval for the complete job.” Most manufacturers have produced posters that can be hung in the shop’s waiting rooms so the technician or service writer can visually explain the complexity of the job to the vehicle owner.

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