The Bilstein B6 Performance 24-264570 is a rear monotube gas-pressure shock absorber for BMW 3 Series applications, including the 320i and 335i listed in this product's title. The manufacturer describes the B6 line as a performance step up from factory dampers, with higher damping force than OE units while keeping the original ride height, so it installs in the factory location without a spring change. For a rear end that feels floaty or tired, that combination of firmer control and unchanged geometry justifies the price over a budget replacement.
Owners on user forums who replaced worn stock rears with B6 units often report better rear traction and less float over bumps and through mid-corner transitions. They also warn against used OE dampers, since worn internals rarely restore the car's original feel, and a new unit gives a predictable baseline. The manufacturer positions the monotube design for consistent damping under repeated hard use, which matters more on spirited back-road runs and track sessions than on daily commutes. Search terms this part suits: BMW F30 rear monotube shock, Bilstein B6 24-264570 320i rear damper, 335i rear shock upgrade, F30 rear shock replacement DIY.
Fitment needs careful checking before you order. Sources list this same part number across several BMW F-series applications, and the model years and drivetrains do not line up from one listing to the next, so confirm your exact year, engine, and xDrive or RWD configuration with the manufacturer. The job is a realistic driveway project with a floor jack, jack stands, and common sockets. Owners on user forums describe removing the rear lower control arm cover, unbolting the lower shock bolt, and then removing the three upper shock-tower bolts before compressing the damper out of the body.
Published fitment for this part number varies between sources, including differing model years and xDrive versus RWD listings. Confirm your exact year, engine, and drivetrain with the manufacturer before ordering.
The manufacturer states that B6 dampers install in place of the factory units and maintain the original ride height, so no spring change is required to fit them.
Difficulty is moderate and suits a home mechanic with a floor jack, two jack stands, and a basic socket set. Plan on a deep 10mm socket for the control arm cover, a 21mm socket for the knuckle bolt, an 18mm socket for the strut-control arm nut, and an E12 socket for the three shock-tower bolts. Owners on user forums advise noting the orientation of the lower bolt, with the head facing the front of the car, and reinstalling it the same way. Support the control arm with a jack before loosening the knuckle bolt, because the spring tension will otherwise make the bolts hard to remove. Always set the car on stands and remove the rear wheels before working underneath.
