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Flywheel / Torque
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
225mm / 6 bolt / 7.4lbs
Fits:
Porsche 911 2.2L / 2.4L / 2.7L 1970-77
Porsche equivalent number: 91110220111
Features:
• Light-weight for improved performance and drastically reduced M.O.I. (Moment of Inertia)
• OEM clutches bolt on for easy installation
• High tolerance manufacturing to insure a perfect hassle free installation
• Designed for normal street use for every day performance enthusiasts
• Stepped dowel pins so they are held captive by the clutch cover
• Racing parts available for the professional
• Highest quality materials for the flywheel like treated steel and OEM quality starter ring gears
• CAD designed/ CNC machined in house for the ultimate in quality control
• One year limited warranty on production components
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
106403-12
The product you are viewing cross references to these numbers
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
Fitting Position: Transmission End
Inner Diameter: 90 mm, Outer diameter: 110 mm, Width: 12 mm
Radial Shaft Seal Design.
Fits:
Porsche 911 3.0L 1978 - 1983
Porsche 911 3.2L 1984 - 1989
Porsche 930 Turbo 1975 - 1989
Diagram Ref No 33
The rear main oil seal fits at the rear of the crankshaft where it passes through the engine case. It helps retain engine oil inside the crankcase and prevents oil from leaking into the flywheel, clutch, or transmission bellhousing area.
Functions
• Replaces the rear crankshaft oil seal
• Helps seal the rear of the engine crankshaft
• Helps prevent engine oil leaks from the bellhousing area
• Protects the clutch and flywheel area from oil contamination
• Supports correct crankcase oil retention
• Replaces hardened, worn, split, leaking, or damaged original seals
• OE Match replacement for Porsche 911 and 930 engine service.
Why Replace This Part?
Rear main oil seals are exposed to heat, crankshaft rotation, oil, pressure changes, and age-related wear. Over time, the seal can harden, shrink, crack, wear, or lose sealing ability. A failed rear main seal may cause oil leaks between the engine and gearbox, oil contamination on the clutch, burning oil smells, or visible oil dripping from the bellhousing area. Replacing the seal helps restore a clean, reliable crankshaft seal.
When to Replace This Part
• Oil is leaking from between the engine and gearbox
• Oil drips are visible from the bellhousing area
• The clutch or flywheel is contaminated with oil
• The engine or gearbox has been removed
• The flywheel is being removed or replaced
• The original seal is hardened, worn, split, or leaking
• Preventative replacement is being carried out during clutch or engine service.
Where it fits on the car
This oil seal fits at the rear crankshaft position on Porsche 911 and 930 engines. It sits between the crankshaft and engine case, behind the flywheel area.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911342641
The product you are viewing cross references to these numbers
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
Fitting Position: Transmission End,
Inner Diameter: 90 mm,
Outer diameter: 110 mm,
Width: 12 mm, Radial Shaft Seal Design.
Fits:
Porsche 911 3.0L 1978 - 1983
Porsche 911 3.2L 1984 - 1989
Porsche 930 Turbo 1975 - 1989
Diagram Ref No 33
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911342642
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 914 (1970-1976)
45 x 60 x 7

Fits:
Porsche 911 1965-83
Porsche 914 1970-76
Click 'Zoom in' for large parts diagram.
Diagram ref no 19
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911318940
The product you are viewing cross references to these numbers
Porsche Flywheels & Torque Converters | Smooth Power Transfer & Engine Balance
Flywheels and torque converters are vital components in your Porsche’s drivetrain, ensuring smooth power transfer from the engine to the transmission. The flywheel provides rotational balance and stores kinetic energy for manual gear changes, while the torque converter in automatic models performs a similar role — transferring engine torque hydraulically for seamless acceleration.
At Design911, we supply precision-engineered flywheels and torque converters designed to meet or exceed original performance specifications. Each component is manufactured from high-grade materials, ensuring strength, balance, and reliability under all driving conditions. Whether you’re restoring a classic 911 or maintaining a modern PDK-equipped Porsche, our range provides the quality and performance your drivetrain demands.
What Do Flywheels & Torque Converters Do?
Both components play critical roles in the performance and drivability of your Porsche, acting as torque-transfer systems between the engine and gearbox.
Flywheels (Manual Transmissions):
Store
rotational energy to maintain engine smoothness.
Provide
a friction surface for clutch engagement.
Aid
in gear transitions by balancing engine speed and torque.
Torque Converters (Automatic Transmissions):
Transfer
torque through fluid dynamics between engine and gearbox.
Enable
smooth gear shifting without clutch operation.
Multiply
torque for efficient acceleration and smoother driving.
Together, they ensure seamless operation, smooth starts, and optimal power delivery from engine to transmission.
Why Do Flywheels & Torque Converters Fail or Wear Out?
Over time, both flywheels and torque converters experience wear due to high rotational forces, friction, and heat cycles.
Common Causes of Failure Include:
- Heat damage or warping from clutch slippage (flywheels).
- Cracked or worn ring gear teeth affecting starter engagement.
- Fluid contamination or internal seal leaks (torque converters).
- Bearing wear leading to vibration or imbalance.
- Excessive torque or misalignment from modified engines.
Symptoms of failure may include clutch chatter, transmission shudder, vibration during acceleration, or slipping during gear changes. Ignoring these signs can lead to further drivetrain damage.
Why Replace your Flywheel or Torque Converter?
Replacing worn flywheels or torque converters restores smooth torque delivery, reduces vibration, and ensures reliable clutch or transmission performance. Upgraded lightweight flywheels improve throttle response, while performance torque converters enhance acceleration and drivability.
Key Benefits:
- Restores smooth engine-to-transmission power delivery.
- Eliminates vibration, slippage, and engagement issues.
- Improves clutch or automatic transmission performance.
- Balances rotational mass for smoother idling and shifting.
- Available in lightweight or performance designs for tuned Porsches.
- Ideal for clutch replacement, transmission rebuilds, or performance upgrades.
It’s strongly recommended to replace the flywheel or torque converter during any major clutch or gearbox service for long-term reliability and balanced performance.
Highlights
- Premium Porsche flywheels and torque converters.
- Precision-balanced for smooth, vibration-free operation.
- Manufactured from high-strength, heat-treated materials.
- Available for manual, automatic, and PDK Porsche models.
- Enhances drivability, acceleration, and transmission longevity.
- Essential for gearbox rebuilds, clutch services, and performance tuning.