The Bilstein B4 22-135049 is a front right twintube strut assembly from the B4 OE Replacement line, built for the front axle of a 2006 BMW 330i. Bilstein B4 OE Replacement dampers are specifically engineered to be the best choice for maintaining the original ride quality of your vehicle, while meeting or exceeding OE standards. That makes it a match for owners who want factory-style damping rather than a firmer aftermarket feel. Search terms this strut targets include 2006 330i E90 front strut replacement, Bilstein B4 OEM twintube strut, and E90 front right OE strut.
Against a worn factory unit, the gain is restored damping control, which is what a tired strut loses first. Against a cheaper unbranded replacement, the B4 is a gas-pressure OE-style damper from a manufacturer that publishes its design intent for the series, so the ride stays close to what the car was engineered to deliver. Because this is a strut assembly rather than a loose damper, the upper mount and bearing setup come together in one unit, which keeps the front-end installation simpler than rebuilding the old strut.
The 2006 330i is an E90-chassis car, and owners on user forums list 06 330i E90 builds alongside front strut parts. Confirm fitment for your VIN and suspension package before ordering, since owners note that regular non-sport springs compress differently than sport springs. Plan on a professional alignment after the swap, and use a proper strut spring compressor for the coil spring work.
Spring inclusion was not consistently confirmed in the information available for this description, so check the package contents before ordering. Owners on user forums describe keeping their factory springs when swapping struts, so many buyers reuse the existing spring.
Owners on user forums identify the 2006 330i as an E90-chassis car, but application data for this part differs between sources. Confirm fitment against your VIN with the manufacturer before ordering.
Owners on user forums describe swapping struts and keeping the old springs, but report that rented spring compressors could not compress the old spring enough to assemble the new strut.
This is an intermediate-to-advanced job for a home garage. The main hurdle is compressing the coil spring, and owners on user forums report it works best when the spring and upper seat are compressed as a unit. Keep the new strut slightly compressed before reinstalling, since the strut would not fit into the wheel well without it. Owners also report that reinstalling was a different story and required the spring to be compressed a bit. Some owners removed the strut without separating the knuckle, while others found the knuckle hard to clear the fender, so plan for both. Get a professional alignment when the job is done.
