Rear Differential

Fits:
Porsche 997.1 C2 / C4 2005-08 (G97.01 / G97.31)
Porsche 997.2 C2 / C4 2009-12 (G97.05 / G97.35)
Click 'Zoom in' for large parts diagram.
Diagram ref no 7
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99733227601
The product you are viewing cross references to these numbers
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche 997 MKII Carrera C2 3.6L 2009-12
- Porsche 997 MKII Carrera C4 3.6L 2009-12

Fits:
Porsche 997 C2
Porsche 997 C4
For Technical Specifications Click Here
Quaife ATB Helical LSD differential for Porsche 997 is suitable for Porsche 997 models. 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 Porsche 997 Quaife ATB Helical LSD differential relies on gears rather than clutch plates for its operation. That means it is much smoother in operation. The Porsche 997 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 Porsche 997 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 997 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 Porsche 997 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 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 for Porsche 997 is also now subject to a lifetime warranty (subject to terms and conditions). Please confirm your application using the attached technical drawing.
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 2S 3.8L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche 997 MK1 Carrera 4S 3.8L 2005-08
6 speed manual - 2 per car

Fits:
Porsche 997.1 Carrera 2 / 2S
Porsche 997.1 Carrera 4 / 4S
Porsche 997.2 Carrera 2 / 2S
Porsche 997.1 Carrera 4 / 4S
Click 'Zoom in' for large parts diagram.
Diagram ref no. 2
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99733224901
The product you are viewing cross references to these numbers
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 2S 3.8L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche 997 MK1 Carrera 4S 3.8L 2005-08
- Porsche 997 MKII Carrera C2 3.6L 2009-12
- Porsche 997 MKII Carrera C4 3.6L 2009-12
- Porsche 997 MKII Carrera C2S 3.8L 2009-12
- Porsche 997 MKII Carrera C4S 3.8L 2009-12
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.