E46 M3 Reinforced Billet Differential Cover Kit - 210/215mm
Single piece 6061 construction, optimized cooling, provisions for temp sensor and external cooler!
Built to last, made from a single piece of 6061 billet aluminum with a rugged and good-looking hard-coat anodizing our diff cover can handle anything you throw at it. Not only is it an absolute masterpiece to look at but this billet diff cover checks all the boxes for features needed. Reinforced mounting ears for strength and stability, never again will you break an ear off your diff cover like the factory units are known to do. Each ear is unified with the one-piece billet cover and features added material for the highest durability possible. This diff cover is cool, literally, the entire construction was designed with optimized cooling in mind. Internal fins are strategically placed serving as effective heat sinks for optimal heat dissipation. This ensures stable temperatures, promoting longevity for both the fluid and your differential. Additionally, the internal design ensures continuous oiling and lubrication of the ring gear, maintaining its stability and preventing fatigue by controlling heat more effectively. An internal baffle at the cover's corner helps maintain proper pressure and prevents cavitation.
All of the OEM features were retained along with the upgrades. The mounting surface was designed to be compatible with both the OEM gasket or RTV of your choosing, some people don't trust the gaskets and we get it. Factory bushing geometry allows you to use any E46 diff busing including rubber, poly, and even solid mounts. The drain and fill plugs on the diff cover are upgraded to -6AN using the provided high-pressure fittings with replaceable o-rings. The drain and fill plugs can now also be used for expanding to an external oil cooler allowing you to further expand the fluid capacity for optimized cooling and service intervals. To keep an eye on things from the driver seat is 1/8 NPT provision for temp sensors, this product from Turner has you covered at every turn.
Why the upgrade?
Upgrading to our Billet Differential cover gives you the strength you need to push your car to its limits. In addition to its enhanced strength, this differential cover includes numerous other upgrades and conveniences. These include increased capacity, improved cooling and lubrication for the ring gear, upgraded fill and drain plugs, and the option to expand an external oil cooler for extreme motorsport usage. Designed to complement both upgraded daily drivers and extensively modified track cars, all while looking good in the process.
Key Benefits:
Reinforced mounting ears for strength and stability - never again will you break an ear off during an aggressive drive or track event
Increased capacity
Sight glass for checking fluid level without removing fill/drain plug
External fins on the casing for maximum cooling and consistent fluid temps
Internal cooling fins for even more temperature control
Optimized internal design to keep fluid consistently on the ring gear
Integrated breather to prevent cavitation by venting the appropriate amount of pressure being built up in the diff housing
-6AN ports to incorporate the use of a differential cooler - this increases capacity and lowers temps allowing for extended fluid change intervals
1/8 NPT fitting for the use of a temp sensor to monitor fluid temperature
Design:
Fits large case 210/215mm differentials
Single piece 6061 Billet aluminum construction
T6 Black hard coat anodizing for superior corrosion resistance and aesthetics
Compatible with most differential coolers(-6AN) and temp sensors(1/8 NPT)
Designed to accommodate oversized rear sway bars
Retains OEM mounting features including the use of the OEM gasket
Factory geometry bushing size for use with OEM and aftermarket poly bushings
Easy access to sensors and drain/fill plug
Retains OEM speed sensor and wire mount location
Product development:
Our Reinforced Billet Diff Cover was designed, engineered, tested, and quality inspected by our Research and Development team at Turner. Nothing but the highest level of precision and quality through leading-edge product development technology including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.
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This product was last offered at the strikethrough price on
05-03-2026
Lifetime Replacement Program! Read more here
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Lifetime Replacement Program! Read more here
This product was last offered at the strikethrough price on
05-03-2026
Lifetime Replacement Program! Read more here
Lifetime Replacement Program! Read more here
Lifetime Replacement Program! Read more here
This product was last offered at the strikethrough price on
05-03-2026
Lifetime Replacement Program! Read more here
This product was last offered at the strikethrough price on
05-02-2026
Lifetime Replacement Program! Read more here
This product was last offered at the strikethrough price on
05-03-2026
This product was last offered at the strikethrough price on
05-07-2026
Product Details
Single piece 6061 construction, optimized cooling, provisions for temp sensor and external cooler!
Built to last, made from a single piece of 6061 billet aluminum with a rugged and good-looking hard-coat anodizing our diff cover can handle anything you throw at it. Not only is it an absolute masterpiece to look at but this billet diff cover checks all the boxes for features needed. Reinforced mounting ears for strength and stability, never again will you break an ear off your diff cover like the factory units are known to do. Each ear is unified with the one-piece billet cover and features added material for the highest durability possible. This diff cover is cool, literally, the entire construction was designed with optimized cooling in mind. Internal fins are strategically placed serving as effective heat sinks for optimal heat dissipation. This ensures stable temperatures, promoting longevity for both the fluid and your differential. Additionally, the internal design ensures continuous oiling and lubrication of the ring gear, maintaining its stability and preventing fatigue by controlling heat more effectively. An internal baffle at the cover's corner helps maintain proper pressure and prevents cavitation.
All of the OEM features were retained along with the upgrades. The mounting surface was designed to be compatible with both the OEM gasket or RTV of your choosing, some people don't trust the gaskets and we get it. Factory bushing geometry allows you to use any E46 diff busing including rubber, poly, and even solid mounts. The drain and fill plugs on the diff cover are upgraded to -6AN using the provided high-pressure fittings with replaceable o-rings. The drain and fill plugs can now also be used for expanding to an external oil cooler allowing you to further expand the fluid capacity for optimized cooling and service intervals. To keep an eye on things from the driver seat is 1/8 NPT provision for temp sensors, this product from Turner has you covered at every turn.
Why the upgrade?
Upgrading to our Billet Differential cover gives you the strength you need to push your car to its limits. In addition to its enhanced strength, this differential cover includes numerous other upgrades and conveniences. These include increased capacity, improved cooling and lubrication for the ring gear, upgraded fill and drain plugs, and the option to expand an external oil cooler for extreme motorsport usage. Designed to complement both upgraded daily drivers and extensively modified track cars, all while looking good in the process.
Key Benefits:
- Reinforced mounting ears for strength and stability - never again will you break an ear off during an aggressive drive or track event
- Increased capacity
- Sight glass for checking fluid level without removing fill/drain plug
- External fins on the casing for maximum cooling and consistent fluid temps
- Internal cooling fins for even more temperature control
- Optimized internal design to keep fluid consistently on the ring gear
- Integrated breather to prevent cavitation by venting the appropriate amount of pressure being built up in the diff housing
- -6AN ports to incorporate the use of a differential cooler - this increases capacity and lowers temps allowing for extended fluid change intervals
- 1/8 NPT fitting for the use of a temp sensor to monitor fluid temperature
Design:
- Fits large case 210/215mm differentials
- Single piece 6061 Billet aluminum construction
- T6 Black hard coat anodizing for superior corrosion resistance and aesthetics
- Compatible with most differential coolers(-6AN) and temp sensors(1/8 NPT)
- Designed to accommodate oversized rear sway bars
- Retains OEM mounting features including the use of the OEM gasket
- Factory geometry bushing size for use with OEM and aftermarket poly bushings
- Easy access to sensors and drain/fill plug
- Retains OEM speed sensor and wire mount location
Product development:
Our Reinforced Billet Diff Cover was designed, engineered, tested, and quality inspected by our Research and Development team at Turner. Nothing but the highest level of precision and quality through leading-edge product development technology including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.
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