System: Audi Magnetic Ride (AMR) — Electronically Adjustable Part Number: 420412019AJ (Latest Revision for 2014–2015 models) Generation: Type 42 (Facelift / Gen 1.5)

The 2014 Audi R8 V10 utilizes the Magnetic Ride system, which employs magneto-rheological fluid in the dampers. This fluid contains microscopic iron particles that align when a magnetic field is applied (via an electric coil inside the damper), changing the oil’s viscosity and damping force in milliseconds.

Technical Specifications

• Damping Technology: Magneto-rheological (MR) active suspension.

• Operating Modes: Selectable via the center console (“Normal” and “Sport”).

• Reaction Speed: Adjusts damping up to 1,000 times per second.

• Architecture: McPherson-style strut with an integrated electronic connector at the top mount.

Replacement & Compatibility Notes

1. Revision History: The “AJ” suffix is the final, most robust revision for the Gen 1 platform. Earlier codes (like 420412019Q or 420412019G) are technically compatible but were prone to leaking. The AJ version features improved internal seals.

2. The “Leaking” Warning: These struts are notorious for “sweating” or leaking over time. If you see significant oil residue on the lower strut body or if the car feels “bouncy” in one corner, the internal fluid has escaped, and the electronic adjustment will no longer function effectively.

3. Replacement in Pairs: It is strongly recommended to replace the Front Left and Front Right struts as a pair. Mixing a brand-new strut with one that has 50,000 km of wear can lead to uneven handling and unpredictable ABS/ESP intervention during hard cornering.

4. No Calibration Required: Unlike the air suspension in the Q7 or RS6, the Magnetic Ride dampers are typically “plug-and-play” regarding software. However, a professional 4-wheel alignment is mandatory after disturbing the front suspension geometry.

Common Part Numbers for this Unit:

• Audi Genuine: 420 412 019 AJ

• Interchange Codes: 420 412 019 AK, 420 412 019 AH (Spyder variants)

• Aftermarket Alternative: Monroe C1521S (Monroe is the original equipment manufacturer for the Audi R8 MR struts).

Professional Installation Tip

When installing the front strut, ensure the electrical connector at the top is fully seated and the wire is routed away from moving parts. A common fault code on the R8 dashboard is caused by the small wiring harness at the top of the strut being pinched or frayed during installation.