BMW E46 M3 Billet 210mm / 215mm Differential Cover Kit

BMW E46 M3 Billet 210mm / 215mm Differential Cover Kit – High-Strength, High-Cooling Upgrade

Upgrade your BMW E46 M3 with a precision-engineered billet aluminum differential cover designed for the 210mm and 215mm large case differentials. Built from a single solid block of 6061 aluminum and finished with a corrosion-resistant hard coat anodizing, this cover delivers exceptional strength, thermal management, and reliability for high-performance street and track use.

Unlike factory covers known for weak mounting ears, this differential cover features fully reinforced mounting points integrated into the one-piece billet construction. The added material provides unmatched durability, eliminating the risk of cracked or broken ears under load.

Cooling was a top priority in this design. External and internal fins increase surface area to reduce fluid temperatures and stabilize diff performance under high stress. Internally, a strategically placed baffle improves fluid dynamics, keeping oil circulating over the ring gear to reduce heat buildup and wear.

This cover includes multiple motorsport-focused features: -6AN ports for optional external oil cooler integration, a 1/8” NPT sensor port for temperature monitoring, and upgraded drain and fill plugs with replaceable O-rings. The mounting surface is compatible with both OEM gaskets and RTV sealants. It retains factory bushing geometry and accepts rubber, polyurethane, or solid mounts, offering flexibility for different builds.

Key Features:

• Reinforced mounting ears for improved strength and reliability
• Internal and external fins for superior cooling and fluid stability
• -6AN ports for external differential oil cooler compatibility
• 1/8” NPT port for temperature sensor installation
• Compatible with OEM or RTV sealing methods
• Works with OEM speed sensor and wire mount
• Factory bushing size retained – supports stock and aftermarket bushings
• Made from one-piece CNC-machined 6061-T6 aluminum
• Hard coat black anodized for corrosion resistance and aesthetics
• Fits BMW E46 M3 210mm / 215mm differentials

Why Upgrade?
This billet differential cover is the ultimate solution for BMW E46 M3 owners seeking improved cooling, increased reliability, and added functionality. Ideal for aggressive street driving, spirited canyon runs, or full track builds, this cover is built to handle high heat, hard launches, and extended abuse—all while looking great under your car.