BMW Accessory Drive Belt Tensioner Assembly - VNE 11288580360

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 VNE

VNE GmbH was founded in 2001 by Volker Natorp in Hamburg, Germany. Volker has a long, storied history in the automotive field. He began his career in the 1970s working for Wulf Gaertner and in the 1990s eventually branched out on his own to start his own sales repping agency. During that time, he represented TMD Friction (Pagid/Textar) and managed all of the North American sales for them and eventually added Schaeffler Automotive to his roster.

In 2007, VNE GmbH relocated to Ganderkesee, Germany and was renamed VNE Automotive GmbH & Co. With continuous growth, the decision was made to solely focus on developing VNE Automotive and, in 2014, the focus became reality with the commissioning of a new warehouse and office space. Today, VNE Automotive prides itself on never having followed the aftermarket trend. VNE Automotive operates in a highly specialized, niche product sector, by only offering OEM automotive spare parts to more than 50 countries worldwide. This is evident from the unique, and sometimes hard to find, product groups spanning engine management, body electrical, and brake systems.