Home
Drivetrain
Differential and Gearing Upgrades

BMW Differential and Gearing Upgrades for BMW 3 Series E30 (1984-1991)

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:

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

ECS Heavy Duty Differential Bushing - E30, 318ti, Z3

T#:30662812

Part#: 055059LA01

In Stock

Sale - Save 56% $ 52.99

This product was last offered at the strikethrough price on
04-28-2026

$ 23.24 USD

Add to Wish List

Qty

Sale - Save 56%

$ 52.99

This product was last offered at the strikethrough price on
04-28-2026

$ 23.24 USD

Add to Wish List

As your E30 ages, the rear differential bushing can crack, dry rot, and split. It's time for an upgrade. The ECS Tuning Heavy Duty Differential Bushing is crafted with performance in mind. Instead of using polyurethane, which is known for increasing NVH, the enthusiasts at ECS chose HD 70D rubber. This material offers a close-to-factory feel without the excess deflection of softer bushings, ensuring a pleasurable driving experience free from differential whine and excess movement.

Features & Benefits:

Eliminates Weak OEM Mount: The aging E30 chassis deserves an upgrade. Replace your old, cracked, and worn factory bushing with this HD alternative for improved performance. Perfect for Street or Track: Constructed from HD rubber instead of polyurethane or Delrin, this bushing provides comfort for daily driving while remaining effective in performance applications. Added Responsiveness: The 70D HD rubber compound is stiffer than the stock material, reducing drivetrain movement and effectively locking down your rear differential. Easy Installation: Precision-manufactured to the exact specifications of your OEM differential bushing, the ECS heavy-duty replacement installs just like the factory component. Whether you are replacing an aging factory bushing, removing excess driveline movement, or balancing performance and comfort, ECS Tuning has you covered with their Heavy Duty Rear Differential Bushing.

Show More Show Less

Condor Speed Shop Differential Stud Kit - 45mm - E30, E28, E36 318ti,...

T#:578193

Part#: DIFSTKT-1

In Stock

$ 32.00 USD

Add to Wish List

Qty

$ 32.00 USD

Add to Wish List

Condor Speed Shop took the hard work out of removing and reinstalling your differential! If you've ever taken out your diff, you know how much of a pain it is to get the bolt holes to line up during re-installation. They never seem to line up perfectly, and getting the bolts to go in can be time-consuming. Condor's diff studs are designed to make your life a little easier. The diff will line up and lift right into the holes every time. 38mm studs are used with OEM or regular subframe bushings. 45mm studs are used with the 12mm riser subframe bushings. You'll need to pull the driveshaft to drop the diff. Use thread locker during install. Recommended for street or race use. Kit includes: 4 Studs 4 Washers 4 Lock Nuts

Show More Show Less

URO Speedometer Impulse Sender E24, E30, Z3, Z1

For vehicles with production date from 09/1987

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

T#:37993402

Part#: 62168355008

In Stock

$ 46.99 USD

Add to Wish List

Qty

$ 46.99 USD

Add to Wish List

This electronic sensor generates electrical pulses based on the final drive. These signals are then processed by the vehicle’s ECU or speedometer gauge to display real-time speed readings on the dashboard.

Show More Show Less

Polyurethane Differential Bushings - E30/Z3

T#:1105908

Part#: PDB-E3095A

Ships in 10 Business Days

$ 49.99 USD

Add to Wish List

Qty

$ 49.99 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

Revshift Differential Studs And Spacers Kit - 12mm - BMW E30 ...

T#:1105928

Part#: DSS-12

Ships in 7 Business Days

$ 39.99 USD

Add to Wish List

Qty

$ 39.99 USD

Add to Wish List

These studs and spacers mount the differential 12mm from the subframe. They are intended to be used with our 12mm offset subframe bushings. When raising the subframe, the spacers allow the differential to mount in the stock location which maintains proper pinion angle. The studs keep the spacers in place making for a quick and easy installation. The spacers are made from 6061 aluminum. The class 12.9 studs have hex key reliefs. We recommend using loctite during installation. Flange nuts are included. Revshift Performance Engineering is a high-performance parts manufacturer with a focus on quality, reliability, and performance. 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

Condor Speed Shop Solid Differential Bushing - E30, E28, Z3 & 318ti ...

T#:587122

Part#: DIFE30

Ships in 2 Business Days

$ 55.00 USD

Add to Wish List

Qty

$ 55.00 USD

Add to Wish List

Condor Speed Shop's E30 solid differential bushing is designed for the street and the track. They use UHMW in all of their suspension bushings because it is stiff, has almost zero deflection yet also absorbs some vibration. It will outlast other types of rubber or urethane bushings. With their solid diff bushing, you won't have to worry about any more rubbery flex in your diff during hard acceleration.

Show More Show Less

URO Speedometer Sensor

For vehicles with production date up to 09/1987

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

T#:35863158

Part#: 62161369906

Ships in 1 Business Day

$ 70.99 USD

Add to Wish List

Qty

$ 70.99 USD

Add to Wish List

BMW URO speedometer / pulse generator is mounted in the back of the differential and provides wheel speed information to the instrument cluster speedometer.

This item fits the following BMWs:
1984-1987 E30 BMW 318i 325e 325es 325i 325ic 325is
1982-1988 E28 BMW 524td 528e 533i 535i 535is M5
1983-6/1987 E24 BMW 633csi 635csi M6
1981-1987 E23 BMW 733i 735i

Show More Show Less

Select Vehicle

Purpose

Category

Differential and Gearing Upgrades
- Differential Bushings (5)
- Drain Plug (1)

Brand

View All Brands

Price

Special Offers

On Sale (2)