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

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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.

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Victor Reinz Shaft Seal with Lock Ring - Differential Output Shaft (7...

T#:596464

Part#: 33107510289

Ships in 1 Business Day

$ 22.99

This product was last offered at the strikethrough price on
05-07-2026

$ 18.99 USD

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$ 18.99 USD

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Shaft Seal

T#:57580031

Part#: 31521428678

Ships in 4 Business Days

$ 17.99 USD

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$ 17.99 USD

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Keep your vehicle running at peak efficiency with this high-quality replacement part from Meistersatz.

Rogue Engineering E46 M3 Differential Bushing (Front Position) FIX ...

T#:54388516

Part#: RE.484.FIX

Ships in 8 Business Days

$ 64.00 USD

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$ 64.00 USD

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A common failure point on the BMW E46 M3 platform occurs when the side differential mounting bolt backs out, leading to stripped threads in the differential cover.

Genuine BMW Differential Dust Cover

T#:174741

Part#: 33137600693

Ships in 1 day

$ 16.99 USD

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$ 16.99 USD

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Genuine BMW Dustcover Plate.

Front Differential Input Shaft Seal

T#:485407

Part#: 31527507697

Ships in 3 Business Days

7% off MSRP $ 13.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 12.99 USD

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7% off MSRP

$ 13.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 12.99 USD

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Seals the input shaft flange to the front differential

Pre-XDrive Transfer Case Service Kit - E46

10X Entries Into Our F80 M3 Sweepstakes

T#:56616376

Part#: 27111226467KT2

Ships in 4 Business Days

$ 48.99 USD

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$ 48.99 USD

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This Transfer Case Service Kit replaces degraded fluid and sealing hardware to maintain proper lubrication within the all wheel drive transfer case. Unserviced transfer case fluid breaks down into sludge and deposits, causing lubrication loss and internal component wear; this service kit prevents internal wear by renewing fluid properties and drain hardware.

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Rein Differential Drain Plug Gasket

2X Entries Into Our F80 M3 Sweepstakes

T#:19654

Part#: 07119963355

Ships in 3 Business Days

$ 2.03 USD

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$ 2.03 USD

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GASKET RING for various sensors and seals.

Limited Slip Differential With Output Shaft Seal - 188 (Small Diff Ho...

10X Entries Into Our F80 M3 Sweepstakes

T#:55965861

Part#: 30309175WKWVTKT2

Ships in 10 Business Days

$ 1,269.99 USD

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$ 1,269.99 USD

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This AutoTech LSD Upgrade Kit pairs AutoTech’s highly engineered 188mm limited-slip differential carrier with a pair of Corteco output shaft seals, giving you everything you need for a leak-free install.

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Shaft Seal - Differential (Axle Drive)

2X Entries Into Our F80 M3 Sweepstakes

T#:54852004

Part#: B46.610

Special Order: No Guaranteed ETA

$ 14.99 USD

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$ 14.99 USD

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

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

2X Entries Into Our F80 M3 Sweepstakes

T#:44733256

Part#: 703.190

Special Order: No Guaranteed ETA

$ 34.99 USD

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$ 34.99 USD

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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

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Febi Drain Plug Gasket

We Price Match - Give Us A Call or Chat!

T#:340702

Part#: 07119963355

Ships in 6 Business Days

$ 1.99 USD

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$ 1.99 USD

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22x27 aluminum sealing ring

Front Differential Bushing - Priced Each

5X Entries Into Our F80 M3 Sweepstakes
We Price Match - Give Us A Call or Chat!

T#:36032352

Part#: 33176770788

Ships on Dec 10, 2026

$ 15.99 USD

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$ 15.99 USD

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The subframe serves as the mounting point for your rear suspension, connecting to the vehicle's body with bushings designed to absorb vibrations. These bushings minimize vibrations transmitted to the cabin while maintaining a secure and stable connection, ensuring tight and reliable suspension performance.

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Front Differential Input Seal Kit - E46, E53, E60, E61, F30

10X Entries Into Our F80 M3 Sweepstakes

T#:41289766

Part#: 31521428678TKT

Back Ordered

$ 52.99

This product was last offered at the strikethrough price on
07-23-2026

$ 50.99 USD

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$ 50.99 USD

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This kit comes with the seal and both dust covers needed to re-seal your vehicles input shaft on the front differential.

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