Doorbusters BMW Differential and Gearing Upgrades for BMW E46 M3 S54 (1999-2005)

Looking to upgrade your drivetrain for durability and performance? The Turner Motorsport Billet Differential Cover Kit, paired with ECS Tuning's Polyurethane Transmission and Differential Mounts, offers the ultimate solution to eliminate drivetrain flex and enhance your BMW M3’s strength. Perfect for street or track use, this kit ensures top-tier performance for your E46 M3.

Turner Motorsport Billet Differential Cover Kit with ECS Polyurethane Differential Bushings

Engineered for strength and designed to handle extreme conditions, the Turner Billet Differential Cover is built from a single piece of 6061 billet aluminum and finished with a hard-coat anodizing for durability and corrosion resistance. It’s reinforced with mounting ears that prevent common failures seen with OEM diff covers, ensuring stability even during aggressive driving.

This high-performance cover features internal cooling fins that help dissipate heat, keeping the fluid cool and prolonging the life of your differential. It also maintains continuous lubrication of the ring gear, preventing fatigue and heat buildup. The cover is compatible with stock and aftermarket bushings, and comes with upgraded -6AN drain and fill plugs for easy maintenance or for expanding to an external oil cooler. A 1/8 NPT fitting is also included, making it easy to install a temp sensor and keep an eye on fluid temperatures.

Key Features:

Reinforced mounting ears: No more broken diff cover ears. Cooling optimized: External and internal fins reduce heat buildup. Increased capacity: Holds more fluid for better performance. Oil cooler ready: -6AN ports for external cooler installation. 1/8 NPT provision: Easily add a temp sensor. Sight glass: Check fluid level without removing plugs. Compatibility:

Fits E46 M3 with large case 210/215mm differentials. Designed for stock, polyurethane, or solid differential bushings. Accommodates OEM speed sensor and wire mounts. ECS Tuning Polyurethane Transmission Mount Set

Tired of soft factory transmission mounts causing mis-shifts or excessive movement? ECS Tuning’s Polyurethane Transmission Mount Set is the solution. With a durable 70A durometer rating, these mounts offer the perfect balance between everyday comfort and track-ready stiffness. For more track-focused drivers, we also offer an 80A durometer option.

These mounts feature a mechanical interlock design, ensuring longevity even in high-torque applications. Resistant to oil, water, and heat, polyurethane lasts longer than rubber and significantly reduces drivetrain deflection, improving power delivery and driving engagement.

Key Features:

Reduces transmission movement: Minimizes mis-shifts and over-revs. Polyurethane construction: Durable, with superior wear resistance. Two options: Choose between 70A for daily driving and 80A for track use. Engaging driving experience: More connected feel between driver and drivetrain. Upgrade your E46 M3 with this robust kit, and bulletproof your drivetrain today! Perfect for enthusiasts pushing their cars to the limit on the street or track.