The Bilstein B6 Performance 24-120395 is a rear monotube shock absorber from the brand's B6 series, which the manufacturer describes as an upgrade over OE dampers for improved handling. Its monotube design is built to deliver consistent, fade-free damping under repeated hard use, so it suits a 330i owner who wants sharper body control on canyon roads or autocross without giving up daily ride quality. For a buyer weighing a cheaper generic shock, the value is in the valving tuned to this application and the German-built construction. The manufacturer lists the unit at about 5.35 lbs.
The manufacturer's fitment listing names the 2006 BMW 330i, but other sources tie the B6 rear shock to different 330i generations, so confirm your chassis by VIN before ordering. Owners on user forums say the rear shock mounts are a common failure point on these cars, so many recommend replacing them at the same time as the shocks. Plan on jacking the car, removing the trunk lining to reach the upper mounts, and holding the piston rod while you torque the top nut. Keywords: Bilstein B6 rear shock 330i, monotube performance shock, BMW 330i rear damper upgrade, B6 shock 24-120395, rear shock mount replacement.
The manufacturer's fitment listing names the 2006 BMW 330i. Other sources associate the B6 rear shock with different 330i generations, so the manufacturer should be contacted with your VIN before purchase.
Owners on user forums commonly advise replacing the rear shock mounts together with the shocks, since the original mounts are described as a weak point that degrades over time.
Owners on user forums who have done rear shock swaps on these BMWs describe the job as manageable for a home mechanic, with one E46 owner estimating roughly 15 to 20 minutes per side. Expect to remove the trunk lining to reach the upper mount nuts, and use a wrench on the piston rod to hold it while tightening the top nut, since it will otherwise spin. Forum notes also warn against gripping the piston rod with vise grips, which can damage the seal. Common fasteners cited include 13 mm, 17 mm, and 18 mm sizes, but those notes come from E46 owners, so verify the procedure for your specific chassis before starting.
