BMW Differential and Gearing Upgrades for BMW E46 M3 S54 (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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Genuine BMW - Corporate Logo
T#:7561
Part#: 22316760944
In Stock
$ 2.99 USD
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Genuine BMW Hex Nut With Plate - M8
This item fits the following BMW Chassis:
E30 M3,E36 M3,E34 M5,E39 M5,E60 M5,E63 M6,E46 M3,E82 1M Coupe,E85 Z4M,E30,E34,E36,E38,E39,E46,E63,E65,E82,E85 Z4,E86 Z4,E89 Z4,E90,E92,E93,F22,F30,F31,F32,F33,F34,F36,F80 M3,F82 M4,F83

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Victor Reinz - Corporate Logo
T#:596464
Part#: 33107510289
Ships in 2 Business Days
$ 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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Rogue Engineering - Corporate Logo
T#:54388516
Part#: RE.484.FIX
Ships in 8 Business Days
New Item
$ 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.

OS Giken - Corporate Logo
T#:34382134
Part#: LSD-TUNE
Ships in 2 Business Days
$ 150.00 USD
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$ 150.00 USD
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Genuine BMW - Corporate Logo
T#:174741
Part#: 33137600693
Ships in 1-2 days
$ 16.99 USD
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Genuine BMW Dustcover Plate.
Rein Differential Drain Plug Gasket
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:19654
Part#: 07119963355
Ships in 3 Business Days
$ 2.03 USD
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GASKET RING for various sensors and seals.

Genuine BMW - Corporate Logo
T#:1002353
Part#: E46M3DIFSER1KT
Ships on Sep 16, 2026
$ 287.99 USD
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$ 287.99 USD
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Elring - Corporate Logo
T#:44733256
Part#: 703.190
Special Order: No Guaranteed ETA
$ 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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Shaft Seal - Differential (Axle Drive)
2X Entries Into Our F80 M3 Sweepstakes
Elring - Corporate Logo
T#:54852004
Part#: B46.610
Special Order: No Guaranteed ETA
New Item
$ 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.

IRP - Individual Racing Parts - Corporate Logo
T#:587020
Part#: IRPDB-46MAL
Special Order: No Guaranteed ETA
$ 151.99 USD
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$ 151.99 USD
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These aluminum mounts are a direct replacement for the stock rubber bushings and have been lightened to remove excess weight. Using aluminum instead of rubber eliminates the "wind up" inherent in rubber mounts, and this deflection slows suspension & drivetrain response. The tradeoff is an increase in NVH. Features: Stiffens chassis/Improves stability Less wear of other components Better durability Provides better control of chassis geometry Replaces OE: 33172282484 Recommended for racing use only Includes: 2 rear aluminum bushing 1 front aluminum bushings
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Febi Drain Plug Gasket
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:340702
Part#: 07119963355
Ships on Oct 6, 2026
$ 1.99 USD
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22x27 aluminum sealing ring