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:

Revshift Polyurethane Differential Bushings - Track / Green (95A) - E...

T#:582011

Part#: PDBE46MGREEN

Ships in 2 Business Days

$ 109.99 USD

Add to Wish List

Qty

$ 109.99 USD

Add to Wish List

Revshift polyurethane differential bushings completely replace the OEM rubber bushings on the E46 M3 and Z4M. These bushings stiffen the differential, improving the vehicle's handling capabilities and eliminating drive-line slop.

Show More Show Less

Premium Differential Service Kit - E46 M3, E9X M3, E82 1 M Coupe ...

Includes BMW SAF-XJ limited slip differential fluid with FM booster

T#:598688

Part#: E46M3DIFSERTMSKT

In Stock

Sale - Save 8% $ 301.99

This product was last offered at the strikethrough price on
05-03-2026

$ 277.83 USD

Add to Wish List

Qty

Sale - Save 8%

$ 301.99

This product was last offered at the strikethrough price on
05-03-2026

$ 277.83 USD

Add to Wish List

Servicing your differential is an important job and should only be completed using high quality components! To ensure our customers are getting exactly what they need, we have put together this limited-slip differential service kit that includes all new fluid from BMW, a new BMW drain plug, and one of our new Titanium Magnetic Differential Drain Plugs!

Show More Show Less

Polyurethane Differential Bushings - E46 Non-M

T#:1105905

Part#: PDB-E4695A

Special Order: No Guaranteed ETA

$ 129.99 USD

Add to Wish List

Qty

$ 129.99 USD

Add to Wish List

Utilizing high-precision machining technologies and their very own Polyurethane Manufacturing Department, every Revshift product is designed, manufactured, and tested in-house at their Detroit, Michigan facility.

Show More Show Less

E46 M3, E9X M3, E34 M5, E39 M5, Z4 M OS Giken Super Lock Limited Slip...

T#:1387

Part#: BM237-HA

Ships in 2 Business Days

$ 1,950.00 USD

Add to Wish List

Qty

$ 1,950.00 USD

Add to Wish List

The M Dynamic limited slip unit on the M3 is designed to be a pure street car differential. It's simply not up to the rigors of professional or amateur racing. The OS Giken Super Lock LSD is giant step up in from a stock M3 lsd unit. It's ready for the extreme conditions of racing, offers 100% progressive locking capability, and is able to do this while operating smoothly and quietly. It's use of advanced technologies that make it perfect for both street cars AND pro race cars... and everything in between. We're excited to be carrying the OS Giken LSD unit in our performance catalog, as we've been using them in our own Championship winning M3 race cars.

OS Giken incorporated revolutionary new ideas when developing the their own limited slip diff, utilizing their accumulated racing knowledge and experience and over 4 years of development. Their design uses an unprecedented number of friction plates (up to 28 total!) for better locking force, better engagement/disengagement, and less generated heat. The end result of their efforts is the OS Giken's OS Super Lock LSD which offers incredible durability and reliability on street and track driven BMWs. The use of highest quality materials, precise machining, forged gears and sound engineering makes this LSD durable and reliable enough for road racing performance (which we can personally vouch for!). This is such a great design, in that it can be used in any situation -- whether it's for a street car, or a 100% Professional race car. Zero break-in required. Super smooth and quiet engagement, and 100% progressive locking capability. Professional installation is recommended.

This Limited Slip Differential Unit fits the following BMWs:
2001-2006 E46 M3 coupe & convertible
2008-2013 E9X M3 coupe & convertible
1991-1995 E34 M5 sedan
1999-2003 E39 M5 sedan
2006-2008 E85 Z4M Z4 M Coupe, Z4 M Roadster

Show More Show Less

E46 Finned Differential Cover Upgrade Kit

T#:401688

Part#: 33117512980KT

Ships in 3 Business Days

$ 367.99 USD

Add to Wish List

Qty

$ 367.99 USD

Add to Wish List

The perfect upgrade for any E46, this finned differential cover increases cooling to the rear differential to prevent over heating and possible damage. This is a complete kit including fluid and drain plugs.

Includes the following

Aluminum finned differential cover
Drain & fill plug with sealing o-ring
2 Quarts of Redline 75w90

Show More Show Less

Performance Differential Cover install kit

T#:556968

Part#: 33112282482KT3

Ships in 10 Business Days

Sale - Save 7% $ 676.14

This product was last offered at the strikethrough price on
05-03-2026

$ 627.61 USD

Add to Wish List

Qty

Sale - Save 7%

$ 676.14

This product was last offered at the strikethrough price on
05-03-2026

$ 627.61 USD

Add to Wish List

This kit includes Turner Motorsport solid aluminum differential race mounts pre installed in the differential cover for a quick install. These mounts where developed by Turner Motorsport for their Grand-Am Cup E46 M3 race cars, the advantages of solid aluminum mounts is increased suspension & drivetrain response, less drivetrain loss resulting in more wheel horsepower, and longevity - they effectively last forever. These CNC-machined mounts are a direct replacement for the stock rubber pieces, and have been lightened to remove excess weight.

Show More Show Less

LSD Tune For OS Giken Differential

T#:34382134

Part#: LSD-TUNE

Ships in 2 Business Days

$ 150.00 USD

Add to Wish List

Qty

$ 150.00 USD

Add to Wish List

IRP Aluminum Differential Bushings - E46 M3

T#:587020

Part#: IRPDB-46MAL

Special Order: No Guaranteed ETA

$ 151.99 USD

Add to Wish List

Qty

$ 151.99 USD

Add to Wish List

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

Show More Show Less

Select Vehicle

Purpose

Category

Differential and Gearing Upgrades

Brand

Price

Special Offers

On Sale (2)

Shipping