The Bilstein B6 Performance 24-118323 is a rear 46mm monotube shock for the 2006 Subaru Legacy GT spec.B. Bilstein presents the B6 line as a performance upgrade for original-equipment dampers, meant to work with the factory springs rather than replace them. Each unit uses gas-pressure monotube construction, a yellow-painted body, and valving set for the specific application.
Owners on user forums describe worn Legacy spec.B dampers as a quiet failure: they often do not leak, so the problem is easy to misdiagnose as a bushing or linkage issue. One owner traced a clunk to worn shocks at about 60,000 miles. Upgrading to a purpose-built replacement is a more predictable fix than a generic budget shock when you want consistent damping from a unit designed for this platform. Shopping keywords: 2006 Subaru Legacy GT spec.B rear shock, Bilstein B6 24-118323, rear monotube shock upgrade, Legacy spec B rear damper replacement.
Application data varies between sources on trim and model-year range, so confirm 2006 Legacy GT spec.B fitment against your VIN with the manufacturer before ordering. Installation is done from the cargo area: owners on user forums report removing the rear seat bottoms, floor panel and side trim held by pop clips to reach the upper mount bolts under the wheel arches.
The manufacturer states that the B6 line replaces original-equipment dampers and is designed to pair with the factory springs, so a spring change is not part of the stated design.
The manufacturer says every B6 shock body receives a yellow paint finish that is tested in a 240-hour salt spray test.
Owners on user forums say the upper mounts are accessible but tight. Some recommend penetrating oil on the nuts and bolts, anti-seize at reassembly, and breaking every bolt loose before removing any of them, since a single stuck fastener can be hard to work around.
Owners on user forums describe the rear shock swap as fairly straightforward for a home mechanic, but the access work takes time. Expect to fold the rear seats, remove the cargo floor panel and side pieces (pop clips can break), and work under the wheel arches with a ratchet and an open-end wrench, since space is tight. Support the vehicle securely, loosen all rear shock fasteners before removing any, and use an impact tool or pry bar if the factory hardware is seized. Confirm fitment and any included hardware with the manufacturer before starting.
