Audi Accessory Drive Belt Tensioner - URO 018302

Product Information

Accessories such as alternators, power steering pumps, water pumps, and A/C compressors are commonly powered by an accessory drive belt, also sometimes called a serpentine belt. For these to all function correctly, an accessory drive belt tensioner applies the proper amount of tension on the belt to keep it from slipping and ensure the entire system is running smoothly.

There are three main styles of accessory belt tensioners, the most popular being the “Automatic” tensioner. An automatic accessory drive belt tensioner is spring-loaded to maintain constant tension on the belt. Some European cars use a hydraulic-style tensioner, which is slightly more complicated but less prone to bouncing or vibrations if one of the accessories is not in top shape. Finally, a manual accessory drive belt tensioner uses a screw and an arm that needs to be manually adjusted. These are usually found on classic cars and need to be checked as part of regular maintenance.

When an automatic tensioner is failing, you will notice an abnormal amount of bouncing or vibration, usually in conjunction with a bad pulley bearing. Hydraulic tensioners will fail similarly, by losing their ability to damp the vibrations in the system and begin to bounce. Sometimes they can also leak, although the amount of fluid in a hydraulic tensioner is small, so it would be hard to detect. If your belt system is bouncing or wobbling due to slack in the tensioner, replace the tensioner and associated components to do a full belt service.

• Slack in the belt: If the accessory drive belt tensioner is going bad, you will notice the belt bounce and hop due to the inability of the tensioner to apply even constant pressure.
• Pulley Bearing Failure: Many accessory drive belt tensioners have a pulley integrated into the assembly. If the pulley bearing goes bad, it will cause inconsistent or excess resistance on the belt which will inhibit the ability of the tensioner to apply constant tension on the accessory drive belt
• False positives: Occasionally if another component is going bad within the accessory drive belt system, such as a power steering pump or A/C compressor, it can cause intermittent drag on the system that will appear as a faulty belt tensioner. If your belt is not running smoothly, check all the other accessories and idler pulleys to make sure they are smooth.

About URO Parts

Manufactured by California-based A.P.A. Industries LLC, the URO Parts brand offers more than 7,000 high-quality replacement parts for European vehicles, which are ideal for both professional and DIY vehicle repair. A.P.A.'s headquarters is equipped with an impressive mechanical and electrical testing laboratory, which is used to validate products prior-to and post-production. Every URO Parts design undergoes comprehensive laboratory testing of metal, rubber, and plastic compounds for tensile strength, shear strength, compression strength, and elasticity order to ensure each part meets or exceeds OE standards for fitment, function, and durability. These components are then manufactured in ISO/IATF 16949 QMS certified facilities to ensure they are consistent with the highest levels of quality in the Automotive Aftermarket. URO also specializes in highly-accurate restoration components for classic European vehicles, including a wide variety of hard-to-find items that are no longer available from the dealer or specialty salvage yards. These URO Classic parts include body seals, exterior and interior trim, drivetrain mounts, engine parts, suspension bushings, steering linkages, lighting, ignition, and more.