Genuine BMW 34108840339 Front Left Disc Brake Rotor 420x40mm

The Genuine BMW 34 10 8 840 339 is an OEM front left disc brake rotor engineered specifically for the high-performance BMW G09 XM. At 420mm in diameter and 40mm thick, this is one of the largest brake discs fitted to a modern BMW road car, purpose-built to meet the substantial braking demands of BMW M's flagship high-performance luxury SUV.

As a Genuine BMW component, this rotor is manufactured to exact factory tolerances, ensuring a precise fit and maintaining the intended relationship between the brake disc, caliper, brake pads, and associated braking hardware. Replacing worn rotors with OEM parts preserves the vehicle's factory braking performance and safety characteristics.

Key Features:

• Genuine BMW OEM part — not aftermarket or remanufactured
• 420mm diameter × 40mm thickness — among the largest front rotors on any production BMW
• Front left (driver side) position — paired with right-side rotor 34 10 8 840 340
• Direct OEM replacement — retains correct dimensions and factory fit
• Ventilated disc design for effective heat dissipation under high-performance braking loads
• Manufactured to BMW M specification for the G09 XM platform

BMW recommends replacing brake discs in pairs during a front brake service. The minimum thickness is stamped on the disc hub; always inspect disc thickness during brake pad replacement and replace when the stamped minimum is reached. This part is sold individually.

OEM Part Number: 34 10 8 840 339 (also referenced as 34108840339)