The Bilstein B6 24-107440 is a rear monotube shock absorber for the 2006 BMW X5 4.4i (E53 generation), built on Bilstein's B6 4600 platform. It uses a 46mm nitrogen-charged monotube body with a floating divider piston that keeps gas and oil separated, and it is meant to pair with the factory spring rather than replace it. For an E53 owner looking for B6 rear shock upgrade, 46mm monotube, or no-spring-change performance, this is the rear damper that matches that platform.
Compared with worn original dampers, the B6 uses digressive valving that responds to how fast the shaft moves, so it can stay compliant over small bumps while controlling larger dips and body motion in corners. The high gas pressure is intended to resist fade when towing or driving hard, and the vulcanized neoprene bushings add durability. Some owners on user forums describe the B6 as quite firm on the X5, so buyers who prioritize a soft stock ride should weigh that trade-off before buying.
Fitment reports conflict. Owners on user forums have reported running B6 dampers on self-leveling cars, but the manufacturer's application data should be checked against your VIN and suspension type before ordering.
No. The manufacturer designs the B6 to work with the original springs, so no spring change is needed.
Owners on user forums describe the B6 as firm on the E53 X5. The manufacturer's digressive valving is intended to keep the ride comfortable over smaller bumps while improving control in larger motions.
This is a rear-axle replacement, so plan to do both sides together for even damping. Owners on user forums report that the shock rod can be unbolted at the top while leaving the upper mount in place, which can save time. Have a standard socket set and penetrating lubricant on hand for seized fasteners, and support the vehicle safely before working under it.
