Product Details

• Article Number: 188C2421 — Ridex rear axle coil spring for the BMW X3 F25 standard suspension configuration. Sold here as a complete pair (2 springs) — the correct replacement quantity for a rear axle service.
• Set Contents: 2 × Ridex 188C2421 coil spring (one for left rear, one for right rear — springs are interchangeable left/right).
• Fitting Position: Rear Axle — one spring installs on each side of the rear axle. Always replaced as a pair to maintain balanced ride height and handling.
• Vehicle Equipment: For vehicles WITHOUT trailer hitch — spec'd for X3 F25 vehicles that were NOT factory-ordered with the towing package. Vehicles with a factory trailer hitch use a heavier-rate spring to compensate for tongue weight; fitting the wrong spring will cause ride-height and handling issues. Check your vehicle's original build sheet or rear bumper for a tow-hitch receiver before ordering.
• Suspension: For vehicles WITHOUT sports suspension — designed for standard-comfort-suspension BMW X3 F25 models. M Sport and BMW Performance-equipped vehicles use stiffer, shorter springs with different spring rates — fitting standard springs to an M Sport vehicle will raise the ride height noticeably and alter the handling character.
• Spring Design: Coil Spring, constant wire diameter — traditional cylindrical coil spring with uniform wire thickness throughout the coil. Provides a linear spring rate (consistent stiffness regardless of compression) — the classic OEM design for comfort-tuned suspension. Differs from progressive-rate springs (variable wire diameter/coil spacing) which stiffen under heavy compression.
• Length: 375 mm — uncompressed free length of each spring. Critical dimension that determines ride height — installing an incorrect-length spring will raise or lower the rear of the vehicle from its design height, affecting headlamp aim, handling balance, and tire clearance.
• Diameter: 122 mm — outer coil diameter. Must match the factory spring seat dimensions in both the upper and lower mounts to seat correctly.
• Thickness 1: 13 mm — wire/coil diameter of the spring material. Determines the spring rate — thicker wire equals stiffer spring. The 13 mm spec is matched to the X3 F25's weight and weight distribution.
• Weight: 2.5 kg per spring (5 kg total per pair). Useful for shipping cost calculations.
• Condition: New — factory-packed in Ridex packaging.
• Manufacturer: RIDEX — AUTODOC's in-house OEM-equivalent aftermarket brand, produced in IATF 16949, ISO 26262, and VDA 6.3 certified factories. Coil springs are heat-treated spring steel, shot-peened for fatigue resistance, and corrosion-protected with epoxy coating for longevity in wet/humid conditions (a plus for Tanzania's coastal climate).
• OEM Cross-References: BMW 33536787202 — direct equivalent to this original BMW part number.
• Vehicle Compatibility: Designed for the BMW X3 (F25, 2010 onwards) and BMW X4 (F26, 2014 onwards) with standard (non-sport) suspension and WITHOUT trailer hitch. Always verify against your vehicle's VIN or existing part number before purchasing — coil spring cross-compatibility varies significantly by individual vehicle options.
• Why Sold as a Pair: Coil springs should NEVER be replaced individually. A single new spring paired with an older/sagging spring creates uneven ride height, pulls the vehicle to one side, causes uneven tire wear, and compromises handling balance. This listing reflects the correct replacement quantity — one purchase = one complete rear-axle coil spring job.
• Replacement Recommendation: Common failure points — sagging springs (noticeable rear-end drop over time, especially when loaded) or outright spring fractures (often at the bottom coil, with a loud "clunk" and visibly uneven rear stance). A professional four-wheel alignment is recommended after installation. Best practice: replace both rear shock absorbers at the same time — worn shocks often accompany sagging springs, and the labor to access one is the labor to access both.
• Safety Note: Coil spring installation requires a heavy-duty spring compressor and proper safety precautions. A compressed coil spring stores substantial kinetic energy — improper handling can cause serious injury. Job best done by a qualified mechanic with the right tools.
• EAN: 4067448276738

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