BMW Hexagon Screw With Flange - Genuine BMW 07129909880

Product Information

BMW Subframe diagram for M440i, 330e, 430i, i4, 330e xDrive, & more

A subframe mount bushing (also referred to simply as a subframe mount) is a vibration-isolating bushing used to connect the front and rear subframe to the vehicle’s main body or unibody. The subframe itself serves as a structural framework to mount key assemblies such as the suspension, engine, and transmission. Because the drivetrain and suspension are mounted to the subframe, they naturally transmit vibrations to the body of the car. The subframe mount acts as an additional cushion, absorbing vibrations, shocks, and road noise while allowing some flexibility in the subframe’s movement. This helps reduce stress on the vehicle’s body and provides a smoother, more comfortable ride.

There are a few common types of subframe mounts. In an OE application such as a stock vehicle, the mount is typically made of solid rubber, voided rubber (some holes to increase flexibility), or occasionally hydraulic-filled rubber. In performance and race applications, minimizing movement in the subframe is important to maintain correct suspension geometry during high G-loads, so going to polyurethane mounts or reinforcements is a popular upgrade.

Aging or torn subframe mounts can cause several issues, including poor handling or tracking of the wheels, inability to maintain an alignment with abnormal tire wear, and bangs or clunks when transferring load front to back, like when braking or accelerating. Inspect the mounts for cracks or tears, or leaks if the mount is hydraulic.

• Bangs and Clunks: If you are experiencing clunks or bangs when going over bumps, or when braking or accelerating is a sign that the entire subframe is moving around excessively and the mounts may be bad.
• Increased Vibration (NVH): Subframe mount bushings are designed to isolate vibrations from the engine and suspension. When they go bad, they will not effectively absorb NVH, and you will feel more vibrations transferred to the cabin.
• Handling and alignment issues: Since the suspension is connected to the subframe, the mounts must be in good shape. If they aren't, the suspension will have more freedom of movement independent from the car body/frame, and it may also be difficult to maintain an alignment.
• Excess Movement: With the car securely off the ground, use a lever like a pry bar between the subframe and the body of the car. If there is excess movement and it is easy to shift the subframe, the mounts should be replaced.

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.