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- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche 997 MKII GT3 2010-11
- Porsche 997 MKII GT2 RS 2011-13
Sold each.

Fits:
Porsche 986 Boxster 1996-04 (G86.20)
Porsche 996 Carrera 1997-05 (G96.00 / G96.30, G96.01/ G96.31)
Porsche 996 Turbo 2000-05 (G96.88)
Porsche 996 GT3 1999-05 (G96.90 / G96.93 / G96.96)
Porsche 997.1 Turbo 2006-09 (G97.88 / G97.50)
Porsche 997.2 GT2 RS 2010-13 (G97.88)
Porsche 997 GT3 2006-11 (G97.90 / G97.90 / G7.92)
Click 'Zoom in' for large parts diagram.
Diagram ref no 4
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
996332266
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005

Fits:
Porsche 996 3.6L / 3.4L C2/C4/C4S
Porsche Boxster 986 3.2L S 6 SPEED
Porsche Boxster 987 3.2L S 6 SPEED
Quaife ATB Helical LSD differential is suitable for the Porsche 996 6-speed (open diff replacement) model. A direct replacement for the standard Porsche differential, the Quaife ATB Helical LSD differential transforms your car's performance.
Unlike a conventional plate-style limited slip differential, the Quaife ATB Helical LSD differential relies on gears rather than clutch plates for its operation. That means it is much smoother in operation.
The Quaife ATB Helical LSD differential never locks harshly with a set pre-load of wheel slip across the driven axle, like a conventional LSD. Rather, the Quaife ATB Helical LSD differential automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree, and never locks.
The Porsche Boxster S Quaife ATB Helical LSD differential has many benefits over a standard open differential, including maximising traction and minimizing wheelspin, eliminating torque steer and snatching in front wheel drive cars compared to conventional LSD units, and a maintenance-free design which retains the standard oil lubrication.
The Quaife ATB Helical LSD differential is proven in circuit and drag racing, rallying and road use, and is produced from Corus steel billets, and is CAD designed and CNC machined, then inspected to ISO 9001 standards.
With over 370 applications, the Quaife ATB Helical LSD differential is second to none. Accept no imitations!
Quaife ATB Helical LSD differentials are used by Ford, General Motors and Daimler-Chrysler as original equipment.
The Quaife ATB Helical LSD differential is also now subject to a lifetime warranty (subject to terms and conditions).
Please confirm your application using the attached technical drawing.
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche 968 CS 3.0L 1993-95

Fits:
Porsche 911 Carrera 3.2L 1984-89
Porsche 911 Turbo 3.3 1978-89
Porsche 964 1989-94
Porsche 993 1995-98
Porsche 996 1998-05
Porsche 986 Boxster 3.2L 2000-04
Porsche 986 968CS 1993-95
Click 'Zoom in' for large parts diagram.
Diagram ref no 20
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911334741
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche 968 CS 3.0L 1993-95
OE Match differential output shaft seal, engineered to replicate the original Porsche component that seals the output shaft on the differential housing. It prevents gear oil from leaking out where the drive axles exit the differential - a critical sealing function in the drivetrain system.
Sold each.
Fits:
Porsche 911 Carrera 3.2L 1984 - 1989
Porsche 911 Turbo 3.3 1978 - 1989
Porsche 964 1989 - 1994
Porsche 993 1995 - 1998
Porsche 996 1998 - 2005
Porsche 986 Boxster 3.2L 2000 - 2004
Porsche 986 968CS 1993 - 1995
Diagram ref no 20
The differential output shaft seal creates a pressure-resistant, low-friction barrier around the rotating driveshaft or axle stub where it exits the differential. It prevents differential oil from escaping the gearbox while allowing rotational movement, helping maintain optimal lubrication of internal gears, bearings, and limited-slip components.
Function: Installed in the differential carrier housing at the output flange, the seal’s elastomer lip bears against the rotating shaft surface, maintaining contact under variable engine speed, gear torque, and temperature conditions. The internal garter spring ensures the lip is held in consistent contact with the shaft surface, helping prevent weeping or drips that can lead to low lubricant levels and accelerated drivetrain wear.
A worn or hard differential output seal can lose its effectiveness over time, leading to leaks, oil drips, and reduced gear oil levels in the differential. Low lubricant can accelerate wear of differential bearings, gears, and limited-slip clutches - ultimately causing expensive internal damage. Replacing the seal with an OE Match component helps preserve proper differential lubrication, reduces contamination of nearby brake and suspension parts with oil, and maintains drivetrain longevity and performance.
When to replace:
• Visible gear oil leakage from the differential area
• Oil accumulating near the rear of the gearbox or under the car
• During differential service or rebuild
• After replacing output shafts/axle flanges
• Preventive maintenance on high-mile vehicles
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911334741
The product you are viewing cross references to these numbers
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche 997 MK1 GT3 2007-09
- Porsche 997 MKII GT3 2010-11
Fits:
Porsche 993
Porsche 996 / turbo / GT3
Porsche 997 GT3
For cars with Porsche LSD fitted - Option Code M220 (Locking differential 40 %)
Upgrade the standard Porsche LSD to these Track Day / Race inspired components for improved, performance traction.
Our plates also provide more grip and superior durability, which makes them an absolute must have for everybody who visits the track regularly.
RacingDiffs Performance LSD clutch plates fits OEM Porsche LSD unit without any modifications:
This kit contains:
- 4 x Clutch/friction discs
- 4 x Hardcore dog ear steel plates
- 2 x Pre-load (spherical) shims
Clutches are perforated for better cooling and great viscosity to resist the oil build-up in the holes between dog ear plates.
It is well known that drilled brake discs improve cooling over solid discs, it is the same with the LSD clutch discs.
The highest quality thermally processed tool steel is used which differentiates our products from any others on the market.
During the final steps of production the clutch plates are coated with special Molybdenum-Ceramic compound which optimizes the best ratio of friction coefficient and durability. This drastically reduces material wear and warping under extreme conditions providing our clutch plates the best possible longevity.
We mastered knowledge in the field of friction materials and coatings, which is the cornerstone of the quality of our products.
All of our clutch plates are thoroughly tested and are currently being used in various racing cars throughout Europe and USA including track, hill climb and rally.
Please Note:
Friction plate upgrade kit should only be fitted by someone with the relevant knowledge and experience.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
95033298308
The product you are viewing cross references to these numbers
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
Push in flange type
Fits:
Porsche 996 3.6L / 3.4L C2/C4/C4S*
Porsche Boxster 986 3.2L S 6 SPEED
Porsche Boxster 987 3.2L S 6 SPEED
*small percentage of cars have bolt on flanges and require differential QDF14Q
For Technical Specifications Click Here
The Differential powers both drive wheels under nearly all conditions. With an ordinary open differential (standard on most cars), precious power is wasted during wheel spin under acceleration. This happens because the open differential shifts power to the wheel with less grip, along the path of least resistance. The Differential, however, does just the opposite. It senses which wheel has better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel.
Differential 20-80%
Manual cars only
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
Bolt on type flange
Fits:
Porsche 996 3.6L TURBO
Porsche 996 3.6L GT2
Porsche 996 3.6L GT3
For Technical Specifications Click Here
The Differential powers both drive wheels under nearly all conditions. With an ordinary open differential (standard on most cars), precious power is wasted during wheel spin under acceleration. This happens because the open differential shifts power to the wheel with less grip, along the path of least resistance. The Differential, however, does just the opposite. It senses which wheel has better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel.
Differential 20-80%
Manual cars only
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005

Fits:
Porsche 986 Boxster 1997 - 2004
Porsche 996 Carrera 1998 - 2005
Click 'Zoom in' for large parts diagram.
Diagram ref no 3
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90030903801
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005

Fits:
Porsche 986 Boxster / S 1999-04*
Porsche 996 Carrera 1998-05*
*Only for models with the six-speed manual transmission.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
996302122
The product you are viewing cross references to these numbers
Porsche Rear Differentials | Precision Power Distribution for Maximum Traction and Performance
The rear differential is one of the most critical components in your Porsche’s drivetrain. It transfers engine power from the transmission to the rear wheels while allowing them to rotate at different speeds during cornering. This ensures balanced handling, traction, and stability — essential for Porsche’s trademark driving dynamics.
At Design911, we supply high-quality rear differentials and differential components engineered to meet or exceed original performance standards. Built from precision-machined gears, hardened steel housings, and performance-grade bearings, each unit ensures smooth torque distribution and dependable strength under demanding conditions.
Whether you’re maintaining a daily driver or upgrading for track use, our Porsche rear differential parts deliver improved traction, cornering precision, and long-term reliability.
What Does the Rear Differential Do?
The rear differential balances rotational speed between the rear wheels while transmitting power from the gearbox to the axles.
Core Functions:
- Distributes torque evenly between rear wheels.
- Allows independent wheel rotation during turns.
- Prevents wheel slip and loss of traction.
- Reduces drivetrain stress and enhances stability.
- Supports optimal cornering control and handling balance.
Without a properly functioning differential, your Porsche may experience wheel spin, vibrations, or loss of power transfer — reducing both performance and safety.
Why Do Rear Differentials Fail or Wear Out?
Over time, continuous stress, torque, and heat exposure can cause differential components to wear, leading to poor lubrication and gear damage.
Common Causes of Failure Include:
- Low or contaminated differential oil causing friction and overheating.
- Bearing wear leading to excessive noise or vibration.
- Gear tooth pitting or chipping from torque overload.
- Seal failure causing oil leaks.
- Corrosion or fatigue from moisture intrusion.
Signs of a failing differential include whining noises, clunking on acceleration, fluid leaks, or uneven tyre wear.
Why Replace or Upgrade Your Porsche Rear Differential?
Replacing a worn or damaged differential restores power delivery, traction, and drivetrain balance. Upgrading to a performance-spec or limited-slip differential (LSD) enhances handling and control — ideal for spirited road or track driving.
Key Benefits:
- Restores smooth, balanced power distribution.
- Eliminates noise, vibration, and gear chatter.
- Improves traction and acceleration out of corners.
- Extends drivetrain longevity through precise engineering.
- Suitable for Porsche 911, Cayman, Boxster, Panamera, and classic models.
- Available in performance or standard specifications.
Replacing the differential during gearbox or axle servicing ensures long-term reliability and optimum drivetrain efficiency.
Highlights
- Premium Porsche rear differentials and components.
- Precision-engineered for torque balance and durability.
- High-strength materials for road, race, or restoration builds.
- Reduces noise, vibration, and harshness (NVH).
- Ideal for upgrades, rebuilds, or performance applications.
- Compatible with manual, Tiptronic, and PDK systems.