Bilstein B4 13-15 BMW 640i Gran Coupe / 650i Gran Coupe Front Left Twintube Strut Assembly | 19-230221

Note: Priced Individually

Bilstein B4 shocks and struts are perfect for restoring the smooth ride you've been missing in your car or truck. Bilstein has spent years developing innovative shock absorbers for the world's top auto manufacturers, and all of their expertise has been wrapped into these B4 Series shocks and struts. Utilizing both twin-tube and monotube technology, these shocks provide an OEM-quality ride at an economical price. Don't settle for a bouncy, uncomfortable ride when you can bring your suspension back to life with Bilstein B4 shocks and struts.

The Bilstein Principle

All Bilstein gas pressure struts/inserts and gas pressure shock absorbers operate on the same principle. They are manufactured with the rod pointing down into the strut tube, thereby utilizing the thicker, stouter body portion of the shock absorber to dissipate side loads. Consequently, due to the increased diameter and surface of the pressure tube, the Bilstein gas pressure strut/insert or shock is better suited to take increased side loads when compared with the conventional version.

Additional advantages, based on development strongly influenced by the motorsport industry, include greater stability, better road handling, and accurate steering. This combined with extremely high quality manufacturing and materials, means Bilsteins will last approximately four times as long as Original Equipment.

Battling Heat Build Up

Conventional shocks trap the heat within the shock body and prevent adequate dissipation, making them prone to heat build up, fade and eventual failure.

Bilstein's patented design allows the excessive heat from the oil to transfer to the outer surface of the shock body and dissipate more efficiently. The dividing piston also permits the oil to expand as heat builds, preventing aeration (foaming) and viscosity loss. This allows the shock to maintain full damping characteristics as temperatures rise.

The tube of a Bilstein gas pressure shock or strut is fabricated using a special extrusion method. This process achieves an extremely tight peak-to-valley tolerance and maintains consistent wall thickness. Bilstein's seamless monotube design provides superior tube strength while maximizing heat dissipation and shock life.

Ride Comfort and Performance Without Compromise

The piston head design allows independent tuning of the compression and rebound damping forces to provide optimum ride comfort and performance without compromise. It features fewer parts than most conventional designs. The product's simple, yet exceptionally functional digressive design contributes to the extreme durability and long life of Bilstein Shock Absorbers.

Better Built

Bilstein's shock bodies are precision formed through a unique seamless extrusion process. This provides superior strength along with high finish tolerances. The shock body is then treated with a special paint finish durable enough to withstand grueling 240-hour salt spray tests. The finished body is mated with a solid, induction-hardened steel chrome plated and polished shaft, machined valving components and highest quality seals.

Bilstein products are backed by an aftermarket lifetime warranty.

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