Turner Custom Limited Slip Differentials - F3X 335/435

A custom differential is one of the best upgrades to have done to your BMW. Not only can you get more performance but you can also get rid of the open diff in non M BMWs or 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.
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F3X 335i/435i Manual Limited Slip and Gearing Differential Upgrade
Diffs by Turner - Corporate Logo
Part#: TMS216177
Direct Ship, Expected Ship Date: Jun 29, 2021
Starting at $2,399.00
Free Shipping
Starting at $2,399.00
Free Shipping
One of the best upgrades to be made is custom building a differential. There are a lot of options to make improvements to the diff including gear sizing changes, added limited slip units, and limited slip lock-up options. It's easy to overlook the differential when planning your car's upgrades but it's one of the best areas to get return from your modification spending. Using a shorter (numerically higher) gear ratio will give you better acceleration and the limited slip effect will help get that power to the pavement. Changing the limited slip lock-up will change how the car behaves in corners - low lock-up will introduce more wheel spin; a higher lock-up will give more grip to the rear wheels but may induce an understeer condition (too much power pushing the car straight); a variable lock-up will give you the optimum balance. Our experience in diff building, car prep, and racing will ensure we get you the correct custom build for your specific driving conditions.

Gearing Changes All 335i/435i differentials have welded internal pieces that require special machining and modification. Our diff builder has perfected the process and using a shorter 3.46 ring and pinion is now no more difficult than any other car. But because of the extensive labor involved, the 3.46 is currently the only gear option offered at this time but it's perfect for keeping the N55 engines on the boost. Using a shorter gear ratio (numerically higher) will give you better acceleration but will reduce your top speed. The higher ratio puts you at a higher RPM point for any given speed. This puts you further up in the power band, giving you more torque to the ground. Refer to the chart below for examples on the difference.

2014 335i, 6-speed manual, 255/30-19" rear tires
(click to expand)
Gear RatioGearSpeedRPM
40 MPH in 4th
3.234th40 MPH2,047 RPM
3.464th40 MPH2,192 RPM
70 MPH Cruise
3.236th70 MPH2,570 RPM
3.466th70 MPH2,752 RPM
5th Gear Speed @ 6,000 RPM
3.235th138 MPH6,000 RPM
3.465th129 MPH6,000 RPM
Speed in 5th gear at 6,000 RPM is for theoretical and comparison purposes only. It doesn't mean that these speeds are actually reachable.

Limited Slip Options. The 335i/435i sadly did not come with a limited slip unit. Instead, BMW used DTC (Dynamic Traction Control) to cut engine power, apply the brake(s), or a combination of both. A limited slip operates independently from either of those systems. With the LSD installed the DTC system does not engage as often. The LSD transfers torque mechanically to the opposite wheel. It will then allow some wheelspin before the traction control kicks in. If you turn off traction control you still have the torque transfer of the LSD working and then wheel spin. So you can get traction in the corner and some wheelspin out of it to facilitate rotation without engine power being cut so soon. We offer several types of F30/F32 limited slip units:
  • traditional 2 or 3-disc LSD (40-60% fixed lock-up - more than the factory M Performance)
  • 3-disc LSD with variable ramp angles (user-variable lock-up)
  • Quaife helical (no clutch discs)
  • OS Giken Superlock multi-plate LSD (0-100% lock-up)
  • OS Giken TractionControlDiff multi-plate LSD (0-100% lock-up) (smoother and quieter version of Superlock)
    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:
    2012+ F30 BMW 335i - Sedan
    2014+ F32 BMW 435i - Coupe
    2014+ F33 BMW 435i - Convertible
    2014+ F36 BMW 435i - Gran Coupe
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    Rear Subframe-Diff Mount Set - Turner Solid Race - E36 318ti, Z3
    Turner Motorsport - Corporate Logo
    Part#: TMS1336
    In Stock
    Starting at $199.90
    Free Shipping
    Starting at $199.90
    Free Shipping
    Made in the USA A BMW’s subframe is the heart of the rear suspension. The differential is part of the subframe, as it is a stress member system. When the subframe moves, so do all of the rear suspension mounting points. Replacing the stock rubber subframe bushings with solid aluminum will limit drivetrain and suspension movement and keep your car’s suspension geometry the way it’s supposed to be. The Delrin diff mount bushing is a near-solid mount that will last longer than the original rubber and does not 'wind up' under load/unload. This transfers more power through the axles to the wheels. The Turner Motorsport E36 318ti and Z3 solid subframe and differential mount bushing kit is a direct replacement for the stock BMW subframe mounts and differential bushing. We have incorporated ideas from our other race style solid bushings not only make these very light weight but also to be fully serviceable and removable in the case of subframe or diff cover replacement. This kit is a legal upgrade in many racing classes.

    Note: solid subframe mounts are only sold with the solid diff mount. Using a rubber diff mount with the solid subframe mount will result in excessive deflection and twist in the diff mount. With the known issue of weak floor and diff mounts on the Z3 we only recommend using solid mounts together.

    Click here for Z3 / E36ti Subframe Mount installation instructions.
    Click here for Z3 / E36ti Differential installation instructions.

    This item fits the following BMWs:
    1995-1999 E36 BMW 318ti
    1997-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M Roadster M Coupe
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