Please wait…

Please wait while we process your order,
do not press the back button…

Ship to United States

+44 208 500 8811

Your Vehicle // Porsche // Boxster 986/987/981 (1997-2016) // Boxster 986 2.7L 2003-04

PorscheBoxster 986/987/981 (1997-2016)Boxster 986 2.7L 2003-04Gearbox / Transmission

Rear Differential

4 4 4 4

Differential Hexagon-head bolt. Porsche 986 Boxster / 996 / 997.1 turbo / 997 GT3

99921715201

Product Information

Differential Hexagon-head bolt. Sold each.
M12 x 1.25 x 22.5

Fits:
Porsche 986 Boxster S - 1999 to 2004 (G86.20)
Porsche 996 Carrera 2 / Carrera 4 - 1997 to 2005 (G96.00/30/01/31)
Porsche 996 GT2 - 2001 to 2005 (G96.88)
Porsche 996 GT3 - 1999 to 2004 (G96.90/G96.93/G96.96)
Porsche 997.1 turbo / GT2 - 2007 to 2008 (G97.88/G97.50)
Porsche 997 GT3 - 2007 to 2012 (G97.90/G97.50)

Click 'Zoom in' for large parts diagram.
Diagram ref no 3

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99921715201

99921715201

The product you are viewing cross references to these numbers

3 3 3

Differential output shaft seal. Porsche 924 / 944 / Boxster / Cayman

016409399B

Product Information

Differential output shaft seal.

Fits:
For cars with manual transmission
Porsche 924 1976-88
Porsche 944 1982-91
Porsche 986 / 987 / 981 / 982 Boxster 1997>>
Porsche 987 / 981 / 982 Cayman 2005>>

Click 'Zoom in' for large parts diagram.
Diagram ref no 4

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

016409399B

016409399B

The product you are viewing cross references to these numbers

3 3 3

Differential output shaft seal. Porsche 924 / 944 / Boxster / Cayman 45 x 60 x 8mm

016409399B/1

Product Information

OE Match differential output shaft seal for selected Porsche 924, 944, Boxster and Cayman manual-transmission applications. The supplied diagram specification is 45 x 60 x 8mm.

Fits
For cars with manual transmission

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 Boxster 987 2.7L 2005-08/08
Porsche Boxster 987 S 3.2/3.4L 2005-08/08
Porsche 944 2.5L 8V 1982-87
Porsche 944 2.7L 8V 1988-89
Porsche 944S 2.5L 16V 1987-88
Porsche 944S2 3.0L 16V 1989-91
Porsche 944 Turbo 2.5L 8V 1985-88
Porsche 944 Turbo 2.5L 8V 1989-91
Porsche 944 Turbo S 2.5L 8V 1988
Porsche Cayman S 3.4L 987C 2005-08
Porsche Cayman 2.7L 987C 2006-08
Porsche 924 2.0L 1976-79
Porsche 924 2.0L 1980-85
Porsche 924 Turbo 2.0L 1979-81
Porsche 924 Turbo 2.0L 1982-84
Porsche 924 Carrera GT 2.0L 1981
Porsche 924 Carrera GTS 2.0L 1982
Porsche 924S 2.5L 1986-87
Porsche 924S 2.5L 1988
Porsche Boxster 987 MKII 2.9L 2009-12
Porsche Boxster S 987 MKII 3.4L 2009-12
Porsche Cayman 2.9L 987C MKII 2009-12
Porsche Cayman S / R 3.4L 987C MKII 2009-12
Porsche Boxster 981 2.7L 2012-16
Porsche Boxster 981 S / GTS 3.4L 2012-16
Porsche Cayman 2.7L 981 2013-16
Porsche Cayman S / GTS 3.4L 981 2013-16
Porsche Cayman GT4 3.8L 2015-16
Porsche Boxster 718 2.0L Manual (300 Bhp) 2017>>
Porsche Boxster 718 2.0L PDK (300 Bhp) 2017>>
Porsche Boxster S 718 2.5L Manual (350 Bhp) 05/2017>>
Porsche Boxster S 718 2.5L PDK (350 Bhp) 05/2017>>
Porsche Cayman 718 2.0L Manual (300 Bhp)
Porsche Cayman 718 2.0L PDK (300 Bhp)
Porsche Cayman S 718 2.5L Manual (350 Bhp)
Porsche Cayman S 718 2.5L PDK (350 Bhp)
Porsche Boxster GTS 718 2.5L Manual (365 Bhp) 05/2017>>
Porsche Boxster GTS 718 2.5L PDK (365 Bhp) 05/2017>>
Porsche Boxster T 718 2.0L Manual (300 Bhp) 01/2019>>
Porsche Boxster T 718 2.0L PDK (300 Bhp) 01/2019>>
Porsche Cayman T 718 2.0L Manual (300 Bhp)
Porsche Cayman T 718 2.0L PDK (300 Bhp)
Porsche Cayman GTS 718 2.5L Manual (365 Bhp)
Porsche Cayman GTS 718 2.5L PDK (365 Bhp)

Diagram Ref No 4

What This Product Does
This radial seal retains lubricant where the differential output shaft passes through its housing, forming a sealing interface around the rotating shaft.

Functions

Limits lubricant escape at the differential output.
Seals the interface between the shaft and housing.

Technical Details

Part reference: 016409399B; radial shaft seal, 45 x 60 x 8mm.
986 Boxster diagram applications: G86.00 M481 five-speed manual, 1997–04; differential G86.00/01, 1997–04.
987 Boxster diagram applications: G87.01 I481 five-speed manual, 2005–08; Boxster S G87.20 I480 six-speed manual, 2007–08.
987C.1 Cayman diagram applications: G8701+ PR:481 five-speed manual, 2.7L 2006–08; differential application, 2.7L 2007–08.
987C.1 Cayman six-speed manual diagram application: G8720,G8721+ PR:480, 2006–08.
Specified diagram quantities: two seals in the 986 and 987 differential assemblies and the listed 987 Boxster S and 987C.1 six-speed transmission assemblies. This is an assembly requirement, not a statement of pack contents.

Symptoms of Fault

Oily deposits around the differential output flange.
Lubricant seepage or drops beneath the transmission.
A recurring leak associated with a hardened or damaged seal.

Why Replacement Matters

Renewing a leaking output seal addresses lubricant loss at this location. Inspect the shaft sealing surface and surrounding components during the repair, as damage or wear elsewhere can contribute to repeat leakage.

FAQs

Will this seal resolve every transmission leak?
No. Establish where the lubricant is escaping before selecting a replacement.
Should sealant be added?
Use additional sealing compounds only when required by the relevant workshop procedure.
Does a matching model name confirm compatibility?
No. Cross-check reference 016409399B, the gearbox identification and the manual-transmission restriction before fitting.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

016409399B

016409399B

314096090323

016409399B

15195

190035410

108768

The product you are viewing cross references to these numbers

4 4 4 4

Hexagon-Head Bolt - M10x1x22.8 - for Differential Housing. Porsche 986 Boxster 2.5L/2.7L / 987.1 Boxster & Cayman 2.7L

N90361401

Product Information

Hexagon-head bolt - M10 x 1 x 22.8 - for the differential housing.

Sold individually; 10 units required per vehicle.

Fits:
Porsche 986 Boxster 2.5L/2.7L 1997-04 - 5-Speed Manual Transmission Only (PR 481)
Porsche 987.1 Boxster 2.7L 2005-08 - 5-Speed Manual Transmission Only (PR 481)
Porsche 987.1 Cayman 2.7L 2006-08 - 5-Speed Manual Transmission Only (PR 481)

Diagram ref. 3.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

N90361401

N90361401

The product you are viewing cross references to these numbers

Limited Slip Differential (LSD) for Quick Acceleration Porsche Cayman & S, Boxter 986/987 (Tiptronic)

QDF15Q

Product Information

Automatic Torque Biasing Differential enables your car to accelerate quicker and corner faster.

Fits:
Porsche Cayman & S, Boxter 986/987 (Tiptronic)

For Technical Specifications Click Here

Quaife ATB Helical LSD differential is for a variety of models including Porsche Cayman & S, Boxter 986/987 (Tiptronic). A direct replacement for the standard open 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 differential automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree, and never locks. The Quaife ATB Helical LSD differential has many benefits over a standard open differential, including maximising traction and minimizing wheel spin, 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 250 applications - the Quaife ATB Helical LSD differential is the best option to utilise your cars performance. 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). This product is available direct from QUAIFE; please confirm your application using the attached technical drawing.

Limited Slip Differential (LSD) for Quick Acceleration Porsche Cayman, Boxster 986/987 (2.7l - 5 speed/Audi 01X)

QDF16Q

Product Information

Automatic Torque Biasing Differential enables your car to accelerate quicker and corner faster.

Fits:
Porsche Boxster 986 and Cayman 987 2.7L models using the 5-speed Audi 01X gearbox

For Technical Specifications Click Here

Quaife ATB Helical LSD differential suitable for various Porsche models, including Boxster 986 and Cayman 987 2.7L models using the 5-speed Audi 01X gearbox.

A direct replacement for the standard Porsche differential, the Quaife ATB differential transforms your car's performance.

Unlike a conventional plate-style limited slip differential, the Porsche Boxster S 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 differential never locks harshly with a set pre-load of wheel slip across the driven axle, like a conventional LSD. Rather, it automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree, and never locks.

The ATB 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 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 differential is second to none. Accept no imitations!

Quaife ATB differentials are used by Ford, General Motors and Daimler-Chrysler as original equipment.

The ATB differential for is also now subject to a lifetime warranty (subject to terms and conditions).

Please confirm your application using the attached techncial drawing.

Pin 5x16. Porsche 986 Boxster / 996 Carrera

90030903801

Product Information

Pin, 5x16, for fixing the bolt of the pinion gears in the differential.

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

90030903801

The product you are viewing cross references to these numbers

4 4 4 4

Seal for Differential Output Shaft - Cover Side - for Porsche 986 / 987-1 Boxster & Cayman (Tiptronic Gearbox)

98639702700

Product Information

Oil seal for the short differential output shaft, located on the side of the gearbox with the differential cover.

Outer Diameter: 90mm.

Fits:
Vehicles With Tiptronic Transmission (PR 249)
Porsche 986 Boxster 1997-04

Porsche 987-1 Boxster 2005-08
Porsche 987-1 Cayman 2006-08

Diagram ref. 3.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

98639702700

98639702700

The product you are viewing cross references to these numbers

3 3 3

Seal For Differential Output Shaft Flange For Porsche 986/987-1 Boxster & Cayman / 996-1 Carrera 3.4L (Tiptronic Gearbox)

99639701500

Product Information

Oil Seal For The Long Differential Output Shaft Flange, Located On The Side Of The Gearbox Without The Differential Cover Plate.

Outer Diameter: 54mm.

Fits:
Vehicles With Tiptronic Transmission (PR 249)
Porsche 986 Boxster 1997>>2004

Porsche 987.1 Boxster MKI 2005>>2008
Porsche 987.1 Cayman 2006>>2008

Porsche 996 Carrera 3.4L 1998>>2001

Diagram Ref No 3

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99639701500

99639701500

The product you are viewing cross references to these numbers

3 3 3

Seal For Differential Output Shaft, Cover Side. Porsche 986 / 987-1 Boxster & Cayman (Tiptronic Gearbox)

98639702700/1

Product Information

Seal For Differential Output Shaft, Cover Side.

The Differential Output Shaft Seal – Cover Side is a OE MATCH drivetrain sealing component designed to prevent gear oil leakage from the differential where the output shaft exits the differential housing. This seal helps maintain proper lubrication inside the differential while protecting internal gears and bearings from contamination.

Fits:

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 Boxster 987 2.7L 2005-08/08
Porsche Boxster 987 S 3.2/3.4L 2005-08/08
Porsche Cayman 2.7L 987C 2006-08
Porsche Cayman S 3.4L 987C 2005-08

Diagram Ref No 3

What This Product Does:

Sealing the differential output shaft opening
Preventing gear oil leaks from the differential housing
Maintaining proper lubrication of internal gears
Protecting internal components from dirt and debris
Supporting smooth and reliable drivetrain operation

Symptoms Of Wear Or Failure:

Gear oil leaks near the differential or axle area
Oil spots under the vehicle
Low differential fluid levels
Whining or grinding noises from the drivetrain
Oil residue around the differential housing or driveshaft connection

Why Replacement Matters:

Prevent gear oil leaks
Maintain proper differential lubrication
Protect gears and bearings from premature wear
Ensure smooth drivetrain performance
Avoid costly differential repairs or replacement

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

98639702700

98639702700

The product you are viewing cross references to these numbers

DISPLAYING 1 to 12 (of 12 products)

Also found on these pages

About Rear Differential

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.

Enter your VAT number here and click Verify:

Your Vehicle // Porsche // Boxster 986/987/981 (1997-2016) // Boxster 986 2.7L 2003-04

Rear Differential

Rear Differential