BMW Supporting Ring - Genuine BMW 37121134899

Product Information

The bump stop in your car’s suspension is designed to prevent the chassis from bottoming out onto the strut or shock absorber when taking excessive or unexpected jounces while driving, such as through construction zones or when carrying heavy loads. By absorbing and dissipating the impact, bump stops are important safety devices to prevent damage to the suspension or chassis from bottoming out.

Bump stops are usually made of dense polyurethane foam rubber, formulated to be relatively stiff and compact while maintaining durability over multiple impacts. Depending on the application, bump stops can have a few different design features, including reinforcements or internal structures. Some performance or sport-oriented vehicles have suspensions that utilize progressive bump stops as a second spring, making it crucial to ensure they are kept in good condition due to their importance in the vehicle’s everyday handling.

Although they are designed specifically to be durable, rubber or polyurethane bump stops will naturally age with time and exposure to the elements. Riding on the bump stops frequently will also significantly shorten their lifespan, so we recommend replacing them every time you replace your struts or shock absorbers.

• Visible cracks or deterioration: With age and frequent use, bump stops can crack or rip, and otherwise deteriorate like most foam rubber. A split bump stop will no longer function correctly and should be replaced to prevent possible damage from an accidental bottoming out.
• Flattening or compression: For cars that use the bump stop more frequently to assist the normal handling of the vehicle, bump stops can become flat or compressed from frequent use.
• Clunking or knocking in extreme compression: If you are experiencing a bang when you go over a harsh dip or bump, you may be bottoming out your suspension due to a damaged or torn bump stop.
• Oil Leaks: While somewhat uncommon, some models of European cars may have a hydraulic bump stop. If they are damaged or torn, the hydraulic fluid will leak out, requiring replacement.

About Genuine BMW

The original parts used by BMW to build your car are available as replacement parts under the “Genuine BMW” brand. When ordering a Genuine BMW part you are guaranteed to get the same part that you would pick up from your local dealerships part department. Genuine BMW parts have been built to BMW’s stringent standards and are the same quality of the original parts used to build your Ultimate Driving Machine.

You may not realize this, but the parts that make up your BMW are not necessarily manufactured by BMW. No cause for concern, as BMW designs the part, hires a manufacturer, and ensures its quality to you. In fact, many of these manufacturers have been making parts for BMW for decades. In our industry these manufacturers are called OEM (Original Equipment Manufacturers), and these are often brands you recognize, including Lemforder, ZF, Sachs, Bosch, Valeo, Zimmermann, Siemens VDO, Corteco, and more. Don’t be surprised to open that Genuine BMW parts box and find an OEM branded part inside, simply with the addition of a BMW logo.

Be sure to keep an eye out for OE tags on our product pages to quickly identify parts coming direct from OE manufacturers. That extra bit of insight could save you some serious money while shopping! Refer to our OE Academy for further information regarding the OE/OEM tags throughout the site.