Car drive belt tensioner

Belt tensioner serves to pull the timing belt. It gets into the timing belt, which runs by the deflection rollers. It is very important the tension to be optimal. In the majority of belt tensioners there is a device which you can use to set up the recommended tension. Thus it is very important to use an appropriate belt tensioner. Otherwise, it is very difficult or impossible to set an appropriate tension.

The belt tensioner is usually replaced together with the timing belt and the guide roller. Thus, you will prevent the belt break. Many belts have indicators that show the system status. Their indications are correctly just in case when all the parts replaced were new. Lifetime of these car parts is indicated by the car parts maker. The replacement must be done by an experienced mechanic.

By all means do not install used belt tensioner. Otherwise you risk spending a lot of money for repair. It is recommended to use torque indicating wrench to tighten the belt tensioner. Before installation, you must clean the entire surface of fitting. Even a small foreign particle can seriously damage the device. Do you want to buy a shock absorber, sidewall, Park Distance Control, centre silencer, fuel filter, clutch cable, clutch pressure plate or other spare parts for your car? Then visit our online store of spare car parts. We have a wide range of products you need.

How to identify a faulty poly-V-belt tensioner arm

To diagnose a component, measure how much the belt is tensioned. A specialized device is required for this purpose. First, inspect the component. To do this, remove the belt and visually inspect the bearing of the tensioner arm. If it is worn or damaged, it should be replaced immediately. Next, visually inspect the bracket. Check whether the component is damaged or bent.

You may notice that the poly-V-belt tensioner arm requires diagnostics by the following symptoms:

• the belt is shifted or is off the shaft, slips or moves freely in the pulley;
• the battery does not indicate charging;
• the belt is excessively or weakly tensioned, or worn unevenly;
• steerability of the vehicle has deteriorated;
• the engine runs unstably;
• jerks during idler pulley rotation;
• traces of the belt are visible on the pulleys;
• the component whistles during operation;
• the idler pulley and the belt vibrate;
• the vehicle brakes spontaneously.

Reasons of poly-V-belt tensioner arm malfunction

A common reason of component failure is its mechanical damage. It may be the result of excessive force applied during assembly, or incorrect adjustment. In addition, the component may be deformed due to impacts in an accident.

The poly-V-belt tensioner arm may be jammed due to damaged spring inside it. Also, the reason may be fouled elements of the component. Traces of oxidation and dirt on the component are caused by ingress of moisture and dust during operation.

Premature wear of the component is often associated with its poor quality. It is recommended to install only original tensioners, since they have properties required for long service life. The component is to be replaced together with the poly-V-belt.

Replacing the poly-V-belt tensioner arm

The component is not subject to repair. To replace it, deenergize the car by disconnecting the battery terminals. Then block the crankshaft with a tire lever so that it could not be rotated. Next, remove the bolts of the belt and loosen it, then remove the tensioner bracket. Unscrew the mounting bolts of the tensioning device, using a set of wrenches, remove the belt and the tensioning arm. Replace defective components with new ones.