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BMW Differential and Gearing Upgrades

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 - Corporate Logo
T#:7917
Part#: 33107510289
Ships in 2 Business Days
$ 25.44 USD
Free Shipping on orders $49 and up
Leaking differential output seals? Replace yours today with this OEM replacement. This seal measures 76x50x10.
OEM BMW Rear Differential Mount - E46, E83 X3, E85 Z4
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:12525
Part#: 33176751808
In Stock
$ 44.99

This product was last offered at the strikethrough price on
04-18-2026

$ 27.99 USD
Free Shipping on orders $49 and up
$ 27.99 USD
Free Shipping on orders $49 and up
RUBBER MOUNTING REAR:331020
Shaft Seal
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Elring - Corporate Logo
T#:591509
Part#: 11117568263
In Stock
$ 22.99 USD
Free Shipping on orders $49 and up
Ideal for engine repairs or addressing leaks into the transmission bell housing, this shaft seal is designed to be mounted on the engine block's upper and lower halves, facing towards the transmission housing.
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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

$ 22.00 USD
Free Shipping on orders $49 and up
$ 22.00 USD
Free Shipping on orders $49 and up

Differential Bushing - Priced Each
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:382582
Part#: 33171131903
Ships in 6 Business Days
$ 28.03 USD
Free Shipping on orders $49 and up
Victor Reinz - Corporate Logo
T#:362359
Part#: 33107505605
Ships in 1-2 days
$ 29.99

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

$ 28.99 USD
Free Shipping on orders $49 and up
$ 28.99 USD
Free Shipping on orders $49 and up
Seals the axle into the differential

Victor Reinz - Corporate Logo
T#:362602
Part#: 33108305033
Ships in 2 Business Days
$ 3.01 USD
Free Shipping on orders $49 and up
Seals the rear differential cover
Rear Differential Bushing - Priced Each
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:349051
Part#: 33171134872
Ships in 3 Business Days
$ 10.99 USD
Free Shipping on orders $49 and up

Elring Differential Axle Seal - E30 E36 E28 E34 E24 E23 E32 Z3 ...
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Elring - Corporate Logo
T#:369495
Part#: 33107505602
In Stock
$ 9.64 USD
Free Shipping on orders $49 and up

Rubber seals are often hardened and damaged by excessive heat and constant temperature changes causing them to become brittle and crack or split. If your seal has split, replace it with a new Elring seal for long reliability and to prevent further problems.

Elring is one of the biggest OEM names in the manufacturing of high quality gaskets that are available for very affordable prices. Elring has supplied many automotive names for years with the gaskets that seal your car's components from day 1 so you can rest assured that these components will last for a long time to come!

Fits the following BMW engines:
E30 318i/is 325e 325i/ix M3
E36 318i/ic/is/ti 323i/is 325i/is 328i/is M3
E28 524td 528e 533i 535i
E34 525i 530i 535i
E24 633CSi 635CSi
E23 733i 735i
E32 735i/iL
Z3 1.9 2.5 2.5i 2.8 3.0i M Coupe/Roadster

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Victor Reinz - Corporate Logo
T#:375022
Part#: 33111206166
In Stock
$ 2.03 USD
Free Shipping on orders $49 and up
Used to seal the pulse generator in the differential case
Elring - Corporate Logo
T#:54852011
Part#: B16.900
In Stock
New Item
$ 33.99 USD
Free Shipping on orders $49 and up
This high-grade Elring replacement gasket set is engineered for drivers who demand factory-level reliability and zero-compromise sealing performance.
ZF - Corporate Logo
T#:54744784
Part#: 24207588763
Ships in 1-2 days
New Item
$ 2.99 USD
Free Shipping on orders $49 and up
If you notice a puddle of transmission fluid forming underneath your vehicle, the output shaft seal may have failed and is leaking. Stop the leak before it can cause internal transmission damage and replace the output shaft seal in your vehicle today. This seal is on the back of your transmission for the front to rear propeller or driveshaft.
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Genuine MINI - Corporate Logo
T#:31589336
Part#: 83192405829
Ships in 9 Business Days
8% off MSRP $ 36.99

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

$ 33.99 USD
Free Shipping on orders $49 and up
8% off MSRP
$ 36.99

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

$ 33.99 USD
Free Shipping on orders $49 and up
Elring - Corporate Logo
T#:44767282
Part#: 082.770
Special Order: No Guaranteed ETA
$ 24.99 USD
Free Shipping on orders $49 and up
$ 24.99 USD
Free Shipping on orders $49 and up
Eliminate differential leaks with all new output shaft axle seals from Elring Replaces BMW p/n 33107568368, 33107505605, & 33100152629
Elring - Corporate Logo
T#:44733256
Part#: 703.190
Special Order: No Guaranteed ETA
$ 34.99 USD
Free Shipping on orders $49 and up
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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Elring - Corporate Logo
T#:54852004
Part#: B46.610
Special Order: No Guaranteed ETA
New Item
$ 14.99 USD
Free Shipping on orders $49 and up
This OEM-quality replacement shaft seal from Elring is the perfect fix for keeping your gear oil where it belongs.

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
Free Shipping on orders $49 and up
22x27 aluminum sealing ring
Febi Rear Differential Carrier Bushing - E53
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:382583
Part#: 33176770456
Special Order: No Guaranteed ETA
$ 44.99 USD
Free Shipping on orders $49 and up
Bushing that presses into the rear subframe at the rear of the differential.

Febi - Corporate Logo
T#:56471642
Part#: 33316792873
Special Order: No Guaranteed ETA
New Item
$ 12.99 USD
Free Shipping on orders $49 and up
The Febi Bilstein Rear Axle Differential Mount provides factory-spec structural retention to keep your differential firmly anchored.
Febi - Corporate Logo
T#:382585
Part#: 33176770866
Back Ordered
$ 47.99

This product was last offered at the strikethrough price on
08-12-2026

$ 34.99 USD
Free Shipping on orders $49 and up
$ 34.99 USD
Free Shipping on orders $49 and up