BMW Differential and Gearing Upgrades

Designed for track drivers, drift enthusiasts, and drag racers alike, this all-in-one driveline upgrade eliminates the factory weak points and reinforces your drivetrain for high-performance abuse. Whether you're laying down 500HP, clutch-kicking through corners, or launching hard at the strip, this cover keeps your differential secure, cool, and ready for battle.

The stock E30 differential cover features a single mounting provision—fine for a stock M20, but guaranteed to fail on your boosted high-horsepower M5X build. After years of broken covers, mounting tabs, and dreams, our team of E30 enthusiasts engineered the ultimate fix.

Unlike the brittle OEM cast aluminum cover, our upgraded differential cover is CNC-machined from 6061-T6 billet aluminum, offering a 30% increase in material strength alone. More importantly, a secondary mounting ear has been integrated into the design for added support, drastically improving stability and driveline shock absorption. The secondary mount is tied into the chassis using a reinforced sheet metal bracket and a billet aluminum plate, allowing for bolt-on installation or welding for ultimate rigidity.

Another major flaw of the factory E30 differential cover is its lack of any cooling provisions, leading to overheated fluid and premature wear. Our engineers solved this issue by incorporating advanced cooling features into the design. Large external fins have been added to the cover, and are optimized using CFD (Computational Fluid Dynamics) analysis to efficiently dissipate heat, reducing overall fluid temperatures. By maintaining a more stable differential temperature, this cover ensures consistent performance and extends the lifespan of your differential fluid. A built-in air duct assists in cooling by increasing airflow around the differential, further preventing heat-related failures. Our cover features optional -6AN fittings, allowing for easy integration of an external fluid cooler if desired. Finally, a 1/8 NPT port is included with the kit to ensure compatibility with fluid temperature monitoring systems.

Precision-machined from 6061-T6 billet aluminum and finished with a black hard coat anodizing, this cover is built to withstand hard use. Despite its robust construction and superior durability, this differential cover retains factory mounting features. This means any E30 188mm differential cover bushing can be installed, allowing you to tailor our upgraded cover to your build. The cover also accommodates large rear sway bars, ensuring fitment on cars with upgraded suspension. Our proprietary removable air duct provides easy access to sensor bungs, fill plugs, and drain plugs, making differential service a breeze.

FEATURES

Unmatched Strength & Durability - Heavily reinforced mounting locations are designed to withstand extreme horsepower, torque, and shock load. Secondary Differential Mount - A built-in secondary mount, integral sheet metal bracket, and billet adapter plate make this the strongest E30 differential cover on the market. Bolt-On or Weld-On Installation - The secondary mount is designed for easy bolt-in installation or can be welded to the chassis for ultimate rigidity. Optimized Cooling - Large external fins, designed using CFD analysis, dissipate heat efficiently, reducing overall differential fluid temperatures. Integrated Breather System - An integrated breather system reduces internal cavitation by properly venting built-up pressure. Enhanced Fluid Management - Includes a 1/8 NPT sensor port for real-time fluid temperature monitoring, and optional -6AN fittings for adding an external fluid cooler. Aerodynamic Air Duct - The included aerodynamic air duct further reduces fluid temperatures, increasing fluid service life and reliability. KIT CONTENTS

Dual Mount Differential Cover Assembly Includes the cover, sheet metal mounting bracket, billet aluminum mounting plate, and aerodynamic air duct. Installation Hardware Kit Includes everything you need to install this masterpiece on your E30! Differential Gasket Choose between a Genuine BMW paper gasket or make your own gasket with Loctite 5970. Optional -6AN fittings (2) for adding an external fluid cooler. Differential Cover Bushings Choose between Powerflex, OE MOOG, and Genuine BMW, or add your own (two E30 188mm differential cover bushings required for installation). Gear Oil Choose between Liqui Moly, Redline, and Genuine BMW, or supply your own fluid for reassembly.

Single piece 6061 construction, optimized cooling, provisions for temp sensor, and external cooler with removable air duct.

Built to last, made from a single piece of 6061 billet aluminum with a rugged and good-looking hard-coat anodizing the Turner diff cover can handle anything you throw at it. Not only is it an absolute masterpiece, but this billet diff cover checks all the boxes for features needed. Reinforced mounting ear for strength and stability. The mounting 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. External fins are strategically placed on the rear face, bottom, and between the mounting ears of the cover, 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 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 be used for 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.

Upgrading to our Turner Billet Differential cover gives you the strength you need to push your car to its limits without worrying about snapping a diff mount from clutch kicking or other shocks to the drivetrain. In addition to its enhanced strength, this differential cover includes numerous other upgrades and conveniences. These include 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, it also offers a visually appealing design.

Key Benefits:

Reinforced mounting ear for strength and stability
16% Increased fluid capacity
External fins on the back side, bottom, and mounting ear on the casing for maximum cooling and consistent fluid temps
Removeable air duct to direct air across the 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 manual transmission Large Case 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
Factory geometry bushing size for use with OEM and aftermarket poly bushings
Removeable air duct for easy access to sensors and drain/fill plug

Modern BMW's are beginning to leave the performance derived handling and power delivery in the past as the demand for more comfort and features rises. The stiff suspension components designed around having the best driving experience from a luxury car has been left for the M models and replaced with soft rubber bushings and mounts. Unfortunately, this is a good move by BMW to support the masses.

The obvious approach was to offer products so the modern BMW can be upgraded into the car the enthusiast desires, superb handling, control, and a direct delivery of power to the rear wheels. When you upgrade to our Delrin subframe mounts you reconnect that power with almost zero negative feedback.

The added appeal to someone looking to take one of these machines on the race track is Delrin can be used when solid mounts are needed and aluminum is not an option with strict regulations found in??Grand-Am, BMW CCA, and other racing series.

Product features:

• Precision machined Delrin(TM) 150 bushings.
• Precision machined 6061-T6 aluminum inserts.?
• Class legal for any racing class that does not allow a solid subframe bushing.?

Performance Benefits:

• Eliminates subframe movement for more direct throttle and suspension? response.?
• Minimizes wheel hop due to subframe deflection and movement.?

?

***Installation Instructions***

These GAC differential bushings/mounts fit the following BMWs:?
2014+?F22 BMW?228i 228iX M235i M235iX?
2012+?F30 BMW?320i 320iX 328i 328iX 335i 335iX - Sedan?
2014+?F34 BMW?328i 328iX 335iX - Gran Turismo?
2014+?F32 BMW?428i 428iX 435i 435iX - Coupe?
2014+?F33 BMW?428i 428iX 435i 435iX - Convertible

2014+?F36?BMW?428iX -Gran Coupe?

Single piece 6061 construction, optimized cooling, provisions for temp sensor, and external cooler with removable air duct.

Built to last, made from a single piece of 6061 billet aluminum with a rugged and good-looking hard-coat anodizing the Turner diff cover can handle anything you throw at it. Not only is it an absolute masterpiece, but this billet diff cover checks all the boxes for features needed. Reinforced mounting ear for strength and stability. The mounting 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. External fins are strategically placed on the rear face, bottom, and between the mounting ears of the cover, 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 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 be used for 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.

Upgrading to our Turner Billet Differential cover gives you the strength you need to push your car to its limits without worrying about snapping a diff mount from clutch kicking or other shocks to the drivetrain. In addition to its enhanced strength, this differential cover includes numerous other upgrades and conveniences. These include 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, it also offers a visually appealing design.

Key Benefits:

Reinforced mounting ear for strength and stability 16% Increased fluid capacity External fins on the back side, bottom, and mounting ear on the casing for maximum cooling and consistent fluid temps Removeable air duct to direct air across the 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 manual transmission Large Case 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 Factory geometry bushing size for use with OEM and aftermarket poly bushings Removeable air duct for easy access to sensors and drain/fill plug

Often overlooked, scheduled rear differential service is very important. Over time gear lube breaks down causing bearings and internal components fail. Regular maintenance will keep your vehicle running properly for years to come.

Please see kit contents tab for included items.

This package of OEM E82 E90 E92 diff mounts replaces the stock rubber diff bushings. On a tuned 335i you may have noticed more driveline shudder or problems hooking up during hard launches. What happens is the stock rubber bushings are under constant flex as engine torque is transmitted through the differential. Under normal driving with a stock car the bushings are rarely stressed. But factor in significant additional torque from a tuned N54/N55 and the stock rubber will quickly show its weaknesses. You may have even broken a diff bolt or two as the heavy differential shifts around. Even non-turbo E82 and E9X models may benefit from fresh bushings.

This is a set of stock rubber bushings, made by OEM supplier Lemforder. They are the same as the Genuine BMW E9X diff mount bushings, but without the more expensive branding. If you're turned off by potential side effects of urethane or Delrin then the OEM diff mounts are your best option. The OEM mounts fit and perform just like the originals so there is no second guessing their quality. If you're looking for an upgrade we offer E9X solid Delrin and aluminum diff mounts that work well, even in street applications.

E9X Diff Mount Set includes:

• 33176760287 x 2, front differential mount
• 33176770866 x 1, rear differential mount
• (new hardware is optional and can be ordered separately below)
  
  This item fits the following BMWs:
  2008-2012 E82 BMW 128i 135i
  2006-2011 E90 BMW 325i 325xi 328i 328xi 328i xDrive 330i 330xi 335d 335i 335xi 335i xDrive - Sedan
  2006-2012 E91 BMW 325xi 328i 328xi 328i xDrive - Wagon
  2007-2013 E92 BMW 328i 328xi 328i xDrive 335i 335is 335xi 335i xDrive - Coupe
  2007-2013 E93 BMW 328i 335i - Convertible

The perfect upgrade for any E46, this finned differential cover increases cooling to the rear differential to prevent over heating and possible damage. This is a complete kit including fluid and drain plugs.

Includes the following

• Aluminum finned differential cover
• Drain & fill plug with sealing o-ring
• 2 Quarts of Redline 75w90