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BMW E93 Differential and Gearing Upgrades

BMW E93 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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Differential Input Shaft Seal - E82 E46 E9X E39 E60 Z4 Replace your leaking differential input seal with this Genuine BMW part. Whenever service is performed on the differential it is a good idea to check / replace any seals. This seal measures 50mm X 80mm X 9mm. We also recommend you replace the securing plate # 33121205138 at the same time.

This item fits the following BMWs:
2011 E82 BMW 1M Coupe
2001-2006 E46 BMW M3
2008-2011 E90 BMW M3 - Sedan
2008-2013 E92 BMW M3 - Coupe
2008-2013 E93 BMW M3 - Convertible
1988 E28 BMW M5
1991-1995 E34 BMW 540i M5
1999-2003 E39 BMW M5
2006-2010 E60 BMW i M5
2011+ F10 BMW M5
1987-1989 E24 BMW M6
2006-2010 E63 BMW M6
2012+ F12 BMW M6
2013+ F06 BMW M6 Gran Coupe
1988-1994 E32 BMW 740i 740il 750il
1990-1999 E31 BMW 840i 840ci 850i 850ci 850csi
2006-2008 E85 BMW Z4 M Roadster M Coupe
Genuine BMW
Part #: 33121213949
Price: $44.36 (USD) 
$55.96 (21% off MSRP)
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OS Giken TractionControl Limited Slip Differential Unit - E82 135i, E9X 335i (LSD)
video: E92 335i with limited slip
click for high quality

As Used on Project E92 335i
A turbocharged BMW such as the 135i or 335i needs traction to put that power to the ground. The stock differential of both the 135i and 335i only put power to one wheel -- this just won't cut it! Upgrading to a limited slip differential means power to BOTH wheels, for better launch, acceleration, grip, and track handling. We're excited to be carrying the OS Giken LSD unit in our performance catalog, as we've used their products on our own Championship winning E46 and E92 race cars.

OS Giken's newest innovation is their quietest and smoothest limited slip unit yet - the Traction Control Differential (TCD). TCD is similar to their excellent Superlock differentials but with additional oil channels and pathways. The added lubrication makes diff operation smoother and quieter than before (not that there were many complaints to begin with). The locking engagement is more progressive than before which makes this diff more suitable for street driving. Track cars and drift cars should still use the Superlock LSD as it will transition to lock sooner. TCD is an evolution of a diff that was already extremely well-engineered for road and track use. Not willing to rest on their laurels, they took their superior engineering a step further.

With the 135i/335i LSD unit, they have incorporated revolutionary ideas into the overall limited-slip design which uses an unprecedented number of friction plates (up to 28 total!) for better locking force, better engagement/disengagement, and less generated heat. 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!). Zero break-in required. 100% progressive locking capability. 

Installation note: BMW differentials use many unique and BMW-only parts and components. Only technicians who are experienced and familiar with BMW parts should perform the installation. The OS Giken LSD is the limited slip unit (or 'chunk') only. It replaces the stock non-LSD chunk but the original ring and pinion and other internals must be installed with the OS Giken unit. This unit will only work on 335i manual differentials with a bolt-in or modified ring gear. Proper setup and spacing is critical for long life operation. Incorrect installation will void the warranty. We also offer the TCD unit pre-installed -  see our performance diff catalog for more info.

The OS Giken TCD Diff unit fits the following BMWs:
2008-2012  E82 BMW   135i with manual transmission
2007-2011  E90 BMW   335i - Sedan with manual transmission
2007-2013  E92 BMW   335i 335is - Coupe with manual transmission
2007-2013  E93 BMW   335i - Convertible with manual transmission
OS Giken
Part #: BM531-HC
Price: $4964.90 (USD) 
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OEM Corteco Differential Input Shaft Seal - E38 E53 E60 E65 E70 and more As seals age, cracks and splits may form, allowing fluid to seep past the seal. Prevent potential differential damage by replacing your old seal with this OEM Corteco seal.
Corteco
Part #: 33107609536
Price: $6.62 (USD) 
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E9X 335i Manual Limited Slip and Gearing Differential Upgrade 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 Most 335i 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 N54 and 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.

2009 335i, 6-speed manual, 255/30-19" rear tires
(click to expand)
Gear RatioGearSpeedRPM
40 MPH in 4th
3.084th41 MPH2,000 RPM
3.464th40 MPH2,250 RPM
70 MPH Cruise
3.086th69 MPH2,500 RPM
3.466th70 MPH2,800 RPM
5th Gear Speed @ 6,000 RPM
3.085th145 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 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 limited slip units for the 335i:
  • traditional 2 or 3-disc LSD (40-60% fixed lock-up)
  • 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:
    3/2007-2011 E90 BMW 335i with manual transmission
    3/2007-2012 E92 E93 BMW 335i with manual transmission
  • Turner Motorsport
    Part #: TMS21527
    Price: $1999.00 (USD) 
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    Differential Drain Plug with O-Ring - Most BMWs This is the front or rear Genuine BMW differential fluid drain plug for many BMWs. This can also be the transfer case plug or automatic transmission plug on some BMWs.

    + Year & Model Applications
    (click to expand)
    This item fits the following BMWs:
    1970-1976 2002 BMW 1600 2002 2002tii
    2008+ E82 BMW 128i 135i 1M Coupe
    1977-1983 E21 BMW 320i 323i
    1984-1991 E30 BMW 318i 318is 318ic 325e 325es 325i 325ic 325is 325ix M3
    1992-1998 E36 BMW 318i 318is 318ti 318ic 323is 323ic 325i 325is 325ic 328i 328is 328ic M3
    1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
    2006-2011 E90 BMW 325i 325xi 328i 328xi 328i xDrive 330i 330xi 335d 335i 335xi 335i xDrive M3 - Sedan
    2006-2012 E91 BMW 325xi 328i 328xi 328i xDrive - Wagon
    2007-2012 E92 BMW 328i 328xi 328i xDrive 335i 335is 335xi 335i xDrive M3 - Coupe
    2007-2012 E93 BMW 328i 335i M3 - Convertible
    1976-1981 E12 BMW 528i 530i
    1982-1988 E28 BMW 524td 528e 533i 535i 535is M5
    1989-1995 E34 BMW 525i 530i 535i 540i M5
    1997-2003 E39 BMW 525i 528i 530i 540i M5
    2004-2010 E60 BMW 525i 525xi 530i 530xi 528i 528xi 528i xDrive 535i 535xi 535i xDrive 545i 550i M5
    2010+ F07 BMW 535i GT, 535i xDrive GT, 550i GT, 550i xDrive GT
    2011+ F10 BMW 528i 528i xDrive 535i 535i xDrive 550i 550i xDrive M5
    1982-1989 E24 BMW 633csi 635csi M6
    2004-2010 E63 BMW 645ci 650i M6
    2012+ F12 BMW 640i 650i
    1981-1987 E23 BMW 733i 735i
    1988-1994 E32 BMW 735i 735il 740i 740il 750il
    1995-2001 E38 BMW 740i 740il 750il
    2002-2008 E65 BMW 745i 745li 750i 750li 760i 760li
    2009+ F01 BMW 740i 740li 750i 750li 750i xDrive 750li xDrive 760li
    1990-1999 E31 BMW 840i 840ci 850i 850ci 850csi
    2004-2010 E83 BMW X3 2.5i X3 3.0i X3 3.0si
    2011+ F25 BMW X3 xDrive28i X3 xDrive35i
    2000-2006 E53 BMW X5 3.0i X5 4.4i X5 4.6is X5 4.8is
    2007-2013 E70 BMW X5 3.0si X5 4.8i X5 xDrive30i X5 xDrive35d X5 xDrive35i X5 xDrive48i X5M
    2008+ E71 BMW X6 xDrive35i X6 xDrive50i X6M
    1997-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M Roadster M Coupe
    2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si Z4 M Roadster M Coupe
    2009+ Z4 BMW Z4 sDrive30i Z4 sDrive35i Z4 sDrive35is
    2000-2003 E52 BMW Z8 Roadster

    Genuine BMW
    Part #: 33117525064
    Price: $6.98 (USD) 
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    E46 M3, E9X M3, E34 M5, E39 M5, Z4 M OS Giken Super Lock Limited Slip Differential Unit 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
    OS Giken
    Part #: BM237-HA
    Price: $1950.00 (USD) 
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    E9X M3 6MT Differential Upgrade - Custom Options


    A custom differential is one of the best upgrades to have done to your E90 or E92 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 E9X M3 gearing depends on which transmission/clutch spec your car has - 6MT or the DCT. The manual transmission cars have a relatively short 3.85 gear ratio on manual transmission cars. 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. But there's always more acceleration to be had with a shorter gear set and we have quite a few to choose from for either transmission. Your speed vs RPM obviously changes with a different gear set. Use the chart below for examples of the differences.



    2009 M3, 6-speed manual, 265/35-19" rear tires

    (click to expand)

    Gear RatioGearSpeedRPM

    4th Gear @ 40 MPH

    3.854th40 MPH2,350 RPM

    4.104th40 MPH2,500 RPM

    4.454th40 MPH2,700 RPM

    70 MPH Cruise

    3.856th70 MPH3,000 RPM

    4.106th71 MPH3,250 RPM

    4.456th71 MPH3,500 RPM

    5th Gear Speed at Redline

    3.855th168 MPH8,250 RPM

    4.105th157 MPH8,250 RPM

    4.455th145 MPH8,250 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.

    *For full core deposit return, factory diff with 3.85 gearing must be sent in*

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

    This item fits the following BMWs:
    2008-2011 E90 BMW M3 6MT - Sedan
    2008-2013 E92 BMW M3 6MT - Coupe
    2008-2013 E93 BMW M3 6MT - Convertible

    Turner Motorsport
    Part #: TMS20540
    Price: $2924.00 (USD) 
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    Genuine BMW Driveshaft Seal 33107609536

    This seal is found where the driveshaft connects to the differential.

    Genuine BMW Shaft Seal - 50X78X10/15
     

    This item fits the following BMW Chassis:
    E70 X5M,E71 X6M,E53 48IS,E38,E39,E53 X5,E63,E65,E70 X5,E71 X6,E82,E89 Z4,E90,E92,E93,F01,F02,F06,F10,F12,F13,F15,F16,F22,F30,F32,F33,F36
     

     

    Genuine BMW
    Part #: 33107609536
    Price: $12.77 (USD) 
    $14.59 (12% off MSRP)
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    OS Giken Limited Slip Differential Fluid - 80w-250 - 1 liter The OS Giken Super Lock LSD Gear Oil 80W-250 1 Liter FR is the OS Giken's very own special blend of gear oil which does an excellent job of lubricating and protecting your Super Lock LSD from failure. Through use of this high quality liquid, your Super Lock LSD will last much longer if regular oil changes are performed.

    Type: FULL SYNTHETIC
    SAE: 80W-250
    API: GL-5
    Flash point: 208℃
    Viscosity: 320.5(40℃), 43.7(100℃)
    OS Giken
    Part #: OS250R
    Price: $49.95 (USD) 
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    ECS Magnetic Differential Oil Drain Plug 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.
    ECS
    Part #: 009314ECS01A
    Price: $21.95 (USD) 
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    E9X M3 DCT Differential Upgrade - Custom Options


    A custom differential is one of the best upgrades to have done to your E90 or E92 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 E9X M3 gearing depends on which transmission/clutch spec your car has - 6MT or the DCT. The DCT comes with a taller 3.15 gear set (taller than the 3.85 used in the manual transmission cars) to make up for the different transmission ratios and the additional 7th gear. But there's always more acceleration to be had with a shorter gear set and we have quite a few to choose from for either transmission. Your speed vs RPM obviously changes with a different gear set. Use the chart below for examples of the differences.



    2009 M3, 7-speed DCT, 265/35-19" rear tires

    (click to expand)

    Gear RatioGearSpeedRPM

    4th Gear @ 40 MPH

    3.154th41 MPH2,750 RPM

    3.624th39 MPH3,000 RPM

    70 MPH Cruise

    3.157th70 MPH2,800 RPM

    3.627th70 MPH3,250 RPM

    6th Gear Speed at Redline

    3.156th171 MPH8,250 RPM

    3.626th149 MPH8,250 RPM

    Why 6th? Because 7th does not have the mechanical advantage to get past wind resistance at these speeds - it is more of a cruise/overdrive gear. Using 6th 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.

    *For full core deposit return, factory diff with 3.15 gearing must be sent in*

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

    This item fits the following BMWs:
    2008-2011 E90 BMW M3 DCT - Sedan
    2008-2013 E92 BMW M3 DCT - Coupe
    2008-2013 E93 BMW M3 DCT - Convertible

    Turner Motorsport
    Part #: TMS213596
    Price: $3074.00 (USD) 
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    OS Giken Superlock Limited Slip Differential Unit - E82 135i, E9X 335i (LSD)
    video: E92 335i with limited slip

    click for high quality
    A turbocharged BMW such as the 135i or 335i needs traction to put that power to the ground. The stock differential of both the 135i and 335i only put power to one wheel -- this just won't cut it! Upgrading to a limited slip differential means power to BOTH wheels, for better lauch, acceleration, and track handling. We're excited to be carrying the OS Giken LSD unit in our performance catalog, as we've used their products on our own Championship winning E46 and E92 race cars.

    With the 135i/335i LSD unit, they have incorporated revolutionary new ideas into the design (4 years in the making!) which 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!). Zero break-in required. Super smooth and quiet engagement, and 100% progressive locking capability.

    Installation note: BMW differentials use many unique and BMW-only parts and components. Only technicians who are experienced and familiar with BMW parts should perform the installation. The OS Giken LSD is the limited slip unit (or 'chunk') only. It replaces the stock non-LSD chunk but the original ring and pinion and other internals must be installed with the OS Giken unit. This unit will only work on 335i manual differentials with a bolt-in or modified ring gear. Proper setup and spacing is critical for long life operation. Incorrect installation will void the warranty. We also offer the TCD unit pre-installed - see our performance diff catalog for more info.

    The OS Giken Superlock Diff unit fits the following BMWs:
    2008-2012 E82 BMW 135i with manual transmission
    2007-2011 E90 BMW 335i - Sedan with manual transmission
    2007-2013 E92 BMW 335i 335is - Coupe with manual transmission
    2007-2013 E93 BMW 335i - Convertible with manual transmission
    OS Giken
    Part #: BM531-HA
    Price: $4149.90 (USD) 
    Direct Ship