Home
Drivetrain
Differential and Gearing Upgrades

BMW Differential and Gearing Upgrades for BMW 3 Series E46 (1999-2005)

Clear BMW chassis

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:

Turner Titanium Magnetic Differential Drain Plug - M22x1.5

T#:593924

Part#: 027030TMS01

In Stock

Sale - Save 25% $ 89.99

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

$ 67.49 USD

Add to Wish List

Qty

Sale - Save 25%

$ 89.99

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

$ 67.49 USD

Add to Wish List

When both extreme-duty protection and saving every gram matters: the Turner Magnetic Differential Drain Plug.

OEM Rein Magnetic Differential Oil Drain Plug - M22x1.5 - Most BMW & ...

2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:38890943

Part#: HWU0065

In Stock

$ 23.99 USD

Add to Wish List

Qty

$ 23.99 USD

Add to Wish List

As components in the differential begin to wear, metal particles become loose in the diff fluid, which can lead to excess wear. This magnetic plug pulls these particles out of suspension, helping to reduce wear over time. Replaces BMW # 33117525064

Show More Show Less

ECS Magnetic Differential Oil Drain Plug - Most BMW & Mini Models ...

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

Add to Wish List

Qty

Sale - Save 25%

$ 62.99

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

$ 47.24 USD

Add to Wish List

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

Loctite 5970 Gasket/Sealing Compound - 50ml

T#:25772539

Part#: 5970

Ships in 1 Business Day

$ 55.23 USD

Add to Wish List

Qty

$ 55.23 USD

Add to Wish List

This Loctite 5970 Sealant is recommended by BMW to be used to seal the rear differential cover and numerous engine oil pans. Also used for multiple MINI, Audi, and VW applications.

M24x1.5mm Magnetic Drain/Fill Plug - Each M44 M52 M54 S54 Engine ...

T#:583896

Part#: 000920ECS01

In Stock

Sale - Save 25% $ 42.99

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

$ 32.24 USD

Add to Wish List

Qty

Sale - Save 25%

$ 42.99

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

$ 32.24 USD

Add to Wish List

Ensure the longevity of your BMW's drivetrain with ECS Tuning's Magnetic Plugs. These plugs are meticulously engineered in-house to provide a perfect fit and feature a permanent magnet attached to the plug body. The magnet effectively attracts and captures tiny abrasive and ferrous metal particles, preventing their circulation through lubrication systems. Metal particles can accumulate due to various conditions such as normal wear, machining operations, casting flaws, and stress usage, leading to excessive wear of vital components. ECS Tuning's Magnetic Plugs help alleviate this concern by trapping these particles, thus safeguarding the internal components of your drivetrain. With a convenient 17mm hex head design, these plugs eliminate the need for special tools required for OEM plugs.

Key Benefits:

Removes abrasive metal particles from drivetrain fluid
Prevents excessive wear to internal components
Meticulously engineered for a perfect fit
Features a permanent magnet for efficient particle capture
Convenient 17mm hex head design for easy installation

Show More Show Less

BMW E46 Z4 Rear Polyurethane Differential Bushing Performance ...

T#:363117

Part#: 002447ECS03

In Stock

Sale - Save 25% $ 88.99

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

$ 66.74 USD

Add to Wish List

Qty

Sale - Save 25%

$ 88.99

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

$ 66.74 USD

Add to Wish List

BMW E46 Z4 Rear Polyurethane Differential Bushing Performance is the ultimate upgrade for enhancing the connection between your BMW's chassis and differential. Designed by Turner Motorsport, this performance bushing replaces the soft factory rubber with durable polyurethane, offering superior control and response. By minimizing vibrations and reducing deflection, this bushing ensures a more direct and responsive driving experience, making it a must-have for any performance-oriented BMW E46 or Z4 owner.

Enhanced Performance: Replaces the soft factory rubber with durable polyurethane for improved driveline response.
Reduced Vibrations: Minimizes vibrations between the chassis and differential, providing a more connected driving experience.
Increased Durability: Made from high-quality polyurethane, offering long-lasting performance under demanding conditions.
Improved Control: Reduces deflection, ensuring a more precise and responsive handling experience.

Show More Show Less

Differential Oil Drain Plug

2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:27405453

Part#: 33117525064

In Stock

$ 14.99

This product was last offered at the strikethrough price on
08-03-2026

$ 9.99 USD

Add to Wish List

Qty

$ 9.99 USD

Add to Wish List

Rein Differential Drain Plug Gasket

2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:19654

Part#: 07119963355

Ships in 3 Business Days

$ 2.03 USD

Add to Wish List

Qty

$ 2.03 USD

Add to Wish List

GASKET RING for various sensors and seals.

Elring Differential Input Shaft Seal - 50x80x9mm - BMW E82 1M, E46 M3...

T#:44733256

Part#: 703.190

Special Order: No Guaranteed ETA

$ 34.99 USD

Add to Wish List

Qty

$ 34.99 USD

Add to Wish List

If your differential is leaking fluid from the input shaft at the front of the diff case, there is a good chance this seal is faulty. Replace your leaking seal with this new seal from Elring to prevent further fluid loss and prevent damage to your differential. Replaces BMW p/n 33121213949, 33121212197, & 33121204847

Show More Show Less

Shaft Seal - Differential (Axle Drive)

T#:54852004

Part#: B46.610

Special Order: No Guaranteed ETA

$ 14.99 USD

Add to Wish List

Qty

$ 14.99 USD

Add to Wish List

This OEM-quality replacement shaft seal from Elring is the perfect fix for keeping your gear oil where it belongs.

Select Vehicle

Purpose

Category

Differential and Gearing Upgrades

Brand

View All Brands

Price

Special Offers

Shipping