BMW E36 188mm Billet Differential Cover

Turner Motorsport presents their BMW E36 188mm Billet Differential Cover, meticulously engineered for superior durability and performance. Crafted from a single piece of 6061 billet aluminum, this differential cover offers enhanced cooling, provisions for a temperature sensor, and compatibility with an external oil cooler, complete with a removable air duct for optimal airflow.

Unmatched Durability and Strength

Constructed with rugged, hard-coat anodized 6061 billet aluminum, this differential cover is built to endure the most demanding driving applications. The reinforced mounting ears provide exceptional strength and stability, eliminating the common issue of broken ears seen in factory units. The unified one-piece design, combined with additional material in critical areas, ensures that this cover can handle the intense shocks typical in motorsport and high-performance driving.

Optimized Cooling Design

External fins are strategically placed on the rear face, bottom, and between the mounting ears, serving as efficient heat sinks to dissipate heat and maintain stable fluid temperatures. This not only extends the life of the differential fluid but also promotes overall differential longevity. The internal design further enhances cooling by ensuring consistent oiling and lubrication of the ring gear, preventing fatigue and maintaining stability.

Comprehensive Features and OEM Compatibility

Turner Motorsport has retained all OEM features while incorporating significant upgrades. The mounting surface is designed to work with both OEM gaskets and RTV, catering to personal preferences. The cover is fully compatible with the OEM speed sensor, featuring a dedicated provision for sensor wire mounting. The factory bushing geometry is preserved, allowing the use of any E36 differential bushing, including rubber, poly, and solid mounts. 

The differential cover also includes upgraded -6AN drain and fill plugs with high-pressure fittings and replaceable o-rings. These plugs can be used for expanding to an external oil cooler, enhancing fluid capacity and cooling efficiency. Additionally, the 1/8 NPT provision for a temperature sensor allows drivers to monitor fluid temperatures in real-time, ensuring optimal performance.

Why Upgrade?

The factory E36 differential cover, though an improvement over previous generations, has its limitations, particularly in high-stress environments. Cast aluminum covers are prone to breaking under intense conditions, making them unsuitable for motorsport or vehicles with increased power. Turner Motorsport’s Reinforced Billet Differential Cover addresses these shortcomings with a robust design that can withstand aggressive driving and track use. 

Key Benefits:

- Fits medium case 188mm differentials
- Reinforced mounting ears for exceptional strength and stability
- External fins for maximum cooling and consistent fluid temperatures
- Removable air duct for enhanced temperature control
- Optimized internal design for continuous lubrication of the ring gear
- Integrated breather to prevent cavitation and manage internal pressure
- -6AN ports for differential cooler integration, increasing capacity and lowering temperatures
- 1/8 NPT fitting for a temperature sensor to monitor fluid temperature

Design and Development

This differential cover is designed with precision and quality, featuring single-piece 6061 billet aluminum construction and T6 black hard coat anodizing for superior corrosion resistance and aesthetics. It is compatible with most differential coolers (-6AN) and temperature sensors (1/8 NPT), designed to accommodate oversized rear sway bars, and retains OEM mounting features, including the use of the OEM gasket. The removable air duct allows easy access to sensors and drain/fill plugs.

Turner Motorsport’s Reinforced Billet Diff Cover has been meticulously designed, engineered, tested, and quality inspected by their in-house Research and Development team. Utilizing advanced technologies such as FARO laser scanning, SolidWorks 3D CAD modeling, in-house 3D printing for rapid prototyping, and rigorous long-term product testing, this differential cover is the ultimate upgrade for any BMW E36 enthusiast seeking unparalleled performance and reliability.