Contact YouTube Blog Twitter facebook Turner Motorsport on Instagram
Login   |

0 item(s) in your Shopping Cart
VAT Mode:
Get notified about money saving
specials & deals for your BMW
enter your email address
  • 18 years of BMW Tuning.
  • Award winning service.
  • 1,000's of parts in stock.
  • Quality BMW Parts only.
  • Hassle-free returns.

  • Find us on Facebook

    E46 M3 Differential Upgrade - Custom Options
    Part #: E46-M3-DIFFERENTIAL

    A custom differential is one of the best upgrades to have done to your E46 M3. Not only can you get more performance but you can also address the weak points in the M Variable limited slip diff. It's easy to forget about the rear axle when you're considering performance upgrades but changing the gearing is in the top 3 things to do to make the car faster. A custom diff is also a rebuilt unit with new seals, bearings, and limited slip unit.

    Gearing The E46 M3 diff comes with a relatively short 3.62 gear ratio. They could use a shorter gear because the engine redline is so high - the car has a long power band and the gear spacing allows you to stay well within that range. There's always more acceleration to be had with a shorter gear set. BMW Motorsport supplies 3.91 or 4.10 options and there are other gear ratios to select in our custom builds. Your speed vs RPM obviously changes with a different gear set. Use the chart below for examples of the differences.

    Gearing Charts:
    2004 M3, 6-speed manual, 275/35-19" rear tires
    (click to expand)
    Gear Ratio Gear Speed RPM
    40 MPH in 4th
    3.62 4th 40 MPH 2,250 RPM
    3.91 4th 40 MPH 2,450 RPM
    4.10 4th 40 MPH 2,550 RPM
    70 MPH Cruise
    3.62 6th 70 MPH 2,650 RPM
    3.91 6th 70 MPH 2,900 RPM
    4.10 6th 70 MPH 3,000 RPM
    5th Gear Speed at Redline
    3.62 5th 175 MPH 8,000 RPM
    3.91 5th 162 MPH 8,000 RPM
    4.10 5th 154 MPH 8,000 RPM
    Why 5th? Because 6th does not have the mechanical advantage to get past wind resistance at these speeds - it is more of a cruise/overdrive gear. Using 5th for comparison purposes is much more relevant than having to take into account wind direction, resistance, grade, elevation, tire sizing, etc. These numbers are for comparisons among gear ratios only, not to determine what your M3 will top out at.

    Limited Slip Options The M3's M Variable locking differential is genius when it's working properly. Unfortunately, as many M3 owners have come to find, the system only has a service life of 80,000 miles (sometimes less) and then the viscous unit inside starts to fail (is your's clunking?). We can rebuild the internals and bring it back to a perfectly-functioning viscous M Variable unit. Or you may choose to lose the variable lock in favor of a traditional clutch-type or helical diff with a set locking. We also build diffs with Quiafe, Kaaz, and OS Giken (favorite of the Turner racing team) limited slip units.

    Core Charge. If we are building a diff from our own stock a refundable core charge will apply until we get your original diff back. You have a maximum of 30 days from the time you receive the diff to send it back us for a refund. Click here for more detail and explanation of the core charge.

    FAQ: For a full FAQ on the custom diff process, click here.

    This item fits the following BMWs:
    2001-2006 E46 BMW M3

    Select Product Options:

    *Select a diff ratio:  
    *Select a limited slip type:  
    *Add REM ring & pinion polish?  Click here for more information about this option...
    *Add REM bearing polish?  Click here for more information about this option...
    *VIN (required)  
    Please enter your VIN so we can confirm fitment:
    *Transmission (required)  Click here for more information about this option...
    Please list your transmission so we can confirm compatibility.
    *Core Charge  Click here for more information about this option...
    $750 Core Charge (refundable), Add $750.00 (USD)

    Base Price: $1,424.00 (USD)
    Customized Price: $1,424.00 (USD)

    Please select the available options below, then click show customized price to enable the Add to Cart / Add to Wishlist buttons.

    Does this fit my BMW?
    Choose your BMW to Verify Fitment

    Check to add to order
    Turner Motorsport Window Stickers (FREE with Purchase!)
    Turner Motorsport Window Stickers (FREE with Purchase!)   $0.00 (USD)

    Product Rating: (0.00)   # of Ratings: 0   Rate It! Click Here to rate this product

    There are no comments for this product. CLICK HERE to be the first one to share your opinion!