Are you getting ready to replace the tensioner assembly in your car? Did you get a bunch of search engine results that mention semi-automatic tensioning? Is there a different type of tensioner that may provide a performance boost or extend the life of your belts and pulleys?

The Search Engines Have Mislead You

Tensioners appear in a wide range of applications around the world, from bicycles to engines to factory-sized packaging machines. Most cars and trucks on the road these days use an automatic tensioner under the hood. Some older models may have a manual tensioner that keeps its belts in place. No current car on the road has a semi-automatic tensioner. Your search results are referring to parts that apply to industrial machinery and processes.

What does the Automatic Tensioner do in Your Car?

The automatic tensioner assembly is part of the serpentine belt system at the front of your engine block. The belt transfers power to run the water pump, alternator, power steering pump, and climate controls. The tensioning arm has a spring inside that maintains the tensioning pulley’s position in relation to the belt and the proper traveling path for the belt. This minimizes wear on the belt and keeps all the pulleys and gears moving at the proper speed.

What Happens when the Automatic Tensioner Fails?

If the tensioner gets too tight or too loose, the belt can fall off the pulleys. That will cause all the pumps and motors it operates to stop working. You will lose power steering, and the engine could overheat due to a lack of circulation in the radiator. In the old days, you could still drive a car with power steering even if the pump failed. In our modern days, most drivers will find it nearly impossible to turn the wheel. The car will likely need a tow to your home or the shop.

Even if the belt does not completely jump off the pulleys, a bad tensioner can make the belt rub as it pushes it out of the proper path. Instead of lasting up to 50,000 miles, the belt could fail after just 10 or 20,000 miles. When there is too much tension, the belt can bend the mounting brackets for the pulleys.

Can the Automatic Tensioner be Adjusted?

Yes, when installing a replacement tensioner assembly, the tension must be set. As such, anytime that you suspect that the tension is too loose or tight, you can adjust it using the same method. Check the specs for the engine that you are working on for the proper alignment of the tensioner arm. You need the proper socket wrench to turn the bolt on the front of the tensioner arm. Make sure that the belt is in place while adjusting the tension so that the optimum path is maintained.

So, go ahead! Place the order for that new automatic tensioner assembly and ignore those sponsored ads for the semi-automatic one. You got the right part the first time.