The ST X coilover kit is a height-adjustable suspension system for the BMW E39 5-Series sedan (525i, 528i, 530i, 540i without factory air suspension), engineered by KW in Germany. It uses galvanized zinc-coated steel struts with a friction-optimized polyamide composite spring perch and stainless-steel insert for corrosion-free ride-height adjustment, plus a hardened chrome piston rod, dust protection system, and monoblock guide for long-lasting daily performance. Each damper is application-specific, hand-built and shock-dyno tested in Fichtenberg, Germany.
| Type | Coilover kit (ST X) |
| Adjustability | Ride height |
| Damping | Fixed |
| Construction | Galvanized zinc-coated steel strut, polyamide composite spring perch with stainless-steel insert |
| Warranty | 5-year limited, unlimited mileage |
Documents: Installation Instructions (PDF)
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2001-2003 | BMW | 525i | Base |
| 1997-2000 | BMW | 528i | Base |
| 2001-2003 | BMW | 530i | Base |
| 1997-2003 | BMW | 540i | Base |
