SACHS shock absorber (311 403) restores factory damping characteristics by controlling spring oscillation on both compression and rebound strokes, recovering steering precision and reducing body roll. Damping configuration — Fitting Position: Front Left, Shock Absorber Type: Aluminium, Shock Absorber Design: Aluminium, Shock Absorber System: Aluminium — is tuned to the original suspension geometry so spring rates and ride height are unaffected, preserving the manufacturer's comfort and handling balance. Mounting dimensions, piston diameter, and stroke length replicate the OEM unit on BMW, BMW (BRILLIANCE) applications, allowing a straight-swap installation without drilling or bracket modification. Supersedes manufacturer part numbers: 22-136572, 31 30 6 771 177, 31 31 6 767 321, 31 31 6 767 323 and 65 more. SACHS dampers are gas-pressure charged, zero-leakage tested on a servo-hydraulic rig, and carry a 2-year unlimited-mileage warranty against manufacturing defects. Shock absorbers gradually lose damping force over time and should be inspected at 50,000 miles and replaced by 80,000–100,000 miles — even if they are not visibly leaking, internal valve wear reduces their effectiveness. Warning signs include excessive body roll in corners, nose-dive under braking, rear-end squat during acceleration, uneven tyre wear, and a bouncy or floaty ride — a simple bounce test (push down on each corner and release) can reveal weak dampers. Shock absorber replacement is an intermediate DIY task that requires spring compressors (for strut-type assemblies), a torque wrench, and penetrating oil for corroded fasteners — allow 2–3 hours per axle. When selecting shock absorbers, match the damper type (twin-tube, monotube, or gas-pressurised) to the original specification — upgrading to a different type can alter ride height and handling characteristics. Always replace shock absorbers in pairs (both sides of the same axle) to maintain balanced handling, and have the wheel alignment checked afterwards — worn dampers often allow geometry to drift out of specification. Every part is dispatched from our UK warehouse with a 30-day money-back guarantee and free hassle-free returns.

Sachs, established in 1895 in Schweinfurt, Germany, is a leading manufacturer of drivetrain and suspension components now part of the ZF Group. Sachs specialises in clutch systems, shock absorbers, dual-mass flywheels, and torque converters. As a tier-one OE supplier to manufacturers including BMW, Mercedes-Benz, Volkswagen, and Audi, Sachs components deliver the same quality found in new vehicles. Choosing Sachs ensures reliable drivetrain performance with products engineered to withstand the most demanding driving conditions.