ECS BMW Differential and Gearing Upgrades for BMW 3 Series E91 (2006-2012)

Clear BMW chassis

Please ensure your correct model is selected

Upgrading various parts of the differential can have tremendous benefits in your car's performance. It's easy to forget that the differential is a source for making your car faster and handle better so it's often overlooked. The engine is not the only place to make the car faster. Our differential options vary from gearing upgrades to limited slip conversions. You can purchase the ring & pinion gear sets on their own (professional installation required) or have us build a diff around your own specifcations. The options are almost endless! Every custom-built diff is fully rebuilt with seals and bearings. We also design and supply bushing options to reduce driveline wind-up, finned differential covers for better cooling, and more!

Ratio Changes - Changing the differential gearing is one of the best and most-effective upgrades you can make on any BMW (old or new). By using a shorter (numerically higher) final drive ratio you are increasing your RPM relative to road speed - this puts you in a more powerful RPM range than before! Since you're in a 'meatier' part of the power band you're now putting down more power/torque to the ground. If you can trade outright top speed for faster acceleration at daily speeds then this is the perfect upgrade for you.

Limited Slip Upgrades - Sadly, many BMWs today are not equipped with a limited slip (posi-traction) differential. BMW has tried to compensate by using traction control that cuts power at the engine or applies the brakes to retard wheel spin (or a combination of both). But nothing beats the function and feel of a a true LSD which may be why BMW continues to use them in M cars. Our LSD upgrades can be done a number of different ways - a factory-type limited slip unit with either 2 or 3 clutch packs, helical type, OS Giken unit, or something truly custom. We can also vary ramp angles and setup to change the limited-slip behavior under acceleration, deceleration, and cornering. Need a custom diff? Call or e-mail to have a quote.

Sub-Categories

Sort By:

ECS Magnetic Differential Oil Drain Plug - Most BMW & Mini Models ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:366828
Part#: 009314ECS01A
In Stock
Sale - Save 25% $ 62.99

This product was last offered at the strikethrough price on
06-13-2026

$ 47.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 62.99

This product was last offered at the strikethrough price on
06-13-2026

$ 47.24 USD
Free Shipping on orders $49 and up
You use a magnetic drain plug for your engine oil, right? Why not apply the same proactive thinking to the differential too? This is a direct replacement magnetic differential drain plug for your BMW. It will catch and retain fine and larger metal particles in your diff oil. If you're proactive in your diff oil servicing, you will catch a minor issue long before it becomes a headache. Diff drain plug includes one sealing o-ring. Direct replacement for Genuine BMW part number(s): 33117525064, 33110308370, 33110152626
Show More Show Less
ECS Complete Performance Polyurethane Differential Bushing Set - 95A ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:589555
Part#: 026709ECS09
In Stock
Sale - Save 15% $ 183.99

This product was last offered at the strikethrough price on
06-14-2026

$ 156.39 USD
Free Shipping
Sale - Save 15%
$ 183.99

This product was last offered at the strikethrough price on
06-14-2026

$ 156.39 USD
Free Shipping
Upgrade your worn OE rubber bushings with ECS Tuning's Performance Polyurethane Differential Bushing Set. In-House Engineered to improve power delivery and handling, with a superior service life over the soft factory rubber bushings.
Show More Show Less
Open Differential Weld Plates - E8x E9x
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:35121162
Part#: 056350LA01
In Stock
Sale - Save 25% $ 30.99

This product was last offered at the strikethrough price on
06-14-2026

$ 23.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 30.99

This product was last offered at the strikethrough price on
06-14-2026

$ 23.24 USD
Free Shipping on orders $49 and up

Convert your open differential to a locked differential without the costly expense of an LSD replacement.

Get your car ready for aggressive track driving or drifting without purchasing or replacing your differential. The weld-in plates strengthen your diff and allow both wheels to engage simultaneously giving you a more predictable and capable track car.

An open differential allows the wheels to spin at different speeds and sends power to the wheel with the least amount of traction. This may be a good feature for your regular everyday driver but limits you on the track. The weld-in plates simulate a driving experience similar to a limited-slip differential allowing you to put power to both wheels in a low traction area or initiate drifts.

Features and benefits:

Added strength to your differential gears
Converts from open differential
Fabricated to fit in the spider gears for an easier weld and increased confidence
Made from 7 gauge mild steel, formed to fit

Show More Show Less