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Gasket Sets / Gaskets / Seals / Lock Nuts
- 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 911 1984-1986 3.2L
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 912E 4CYL 1976
Gear Selector Shaft Oil Seal
OE Match gear selector shaft oil seal for
classic Porsche 911 and 912 manual gearboxes. Designed to replace a worn or
leaking original seal, this component helps prevent transmission oil from
escaping around the gear selector shaft where it passes through the gearbox
housing.
Fits:
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 911 1984-1986 3.2L
Porsche 911 1975-1977 3.0L Turbo (930)
Porsche 911 1978-1989 3.3L Turbo (930)
Porsche 912E 4CYL 1976
Diagram ref no 8
The seal provides a barrier between the moving selector shaft and gearbox casing, helping retain the correct transmission oil level and protecting the surrounding components from oil contamination.
What Does the Gear Selector Shaft Oil Seal Do?
The gear selector shaft transfers movement from the gear lever linkage into the gearbox, allowing the driver to select different gears.
The oil seal fits around this shaft and prevents gearbox oil from escaping while allowing the shaft to move during gear changes. A properly functioning seal helps maintain the transmission oil level and keeps the gearbox exterior clean and dry.
Why Does It Fail?
Over time, the sealing material can harden, shrink or lose flexibility due to age, heat and prolonged contact with transmission oil.
Common causes of failure include:
- Age-related deterioration of the sealing lip
- Hardened or cracked rubber
- Wear from repeated selector shaft movement
- Corrosion or damage to the shaft sealing surface
- Incorrect installation or previous gearbox repairs
- Excessive shaft movement or wear
As the seal deteriorates, transmission oil may begin to seep around the selector shaft.
When Should It Be Replaced?
A replacement may be required if you notice:
- Gearbox oil leaking around the selector shaft
- Oil collecting on the underside of the transmission
- Drips beneath the gearbox
- A persistent oily residue around the selector linkage
- A damaged or hardened seal during gearbox servicing
The seal should also be inspected whenever the gearbox selector mechanism is dismantled or the transmission is removed for restoration.
Checks During Replacement
Before fitting a new oil seal, inspect the selector shaft for corrosion, scoring or excessive movement. Check the gearbox breather and surrounding seals to ensure the leak has been correctly identified.
The new seal should be installed squarely and to the correct depth, without damaging the sealing lip or shaft surface.
Porsche 911 / 912 Gearbox Oil Seals & Transmission Components
Gearbox oil seals are essential for maintaining the correct lubrication of classic Porsche manual transmissions. The gear selector shaft oil seal prevents transmission oil from leaking where the selector shaft enters the gearbox housing.
On older Porsche 911 and 912 models, ageing seals can become brittle or worn, allowing gearbox oil to escape. Replacing a leaking seal helps protect the transmission against lubricant loss and prevents oil contamination around the gear linkage and gearbox casing.
OE Match seal is a 15 × 24 × 7 mm replacement selector shaft oil seal for selected Porsche 911, 912 and 930 Turbo manual gearboxes. It is particularly suitable for maintenance and restoration of classic Porsche transmissions.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99911318540
The product you are viewing cross references to these numbers
Porsche Gearbox & Transmission Gasket Sets, Gaskets, Seals & Lock Nuts | Precision Sealing for Drivetrain Integrity
Gaskets, seals, and lock nuts are essential components that protect your Porsche’s gearbox or transmission system from fluid leaks, contamination, and vibration. These parts maintain internal pressure, ensure proper lubrication, and secure vital fasteners under extreme temperature and torque conditions — all of which are crucial for reliable, long-term gearbox performance.
At Design911, we supply premium gearbox gasket sets, individual seals, and locking hardware engineered to match or exceed original performance specifications. Manufactured from advanced composite, rubber, and metal-reinforced materials, our gasket kits ensure a perfect fit and dependable sealing across all Porsche models.
Whether you’re performing a gearbox rebuild, addressing a transmission leak, or refreshing driveline components, our gaskets, seals, and lock nuts deliver precision, reliability, and protection against future wear or oil loss.
What Do Gearbox Gaskets, Seals & Lock Nuts Do?
Each component plays a vital role in maintaining your Porsche’s gearbox integrity and smooth power delivery.
Core Functions:
Together, they preserve internal oil pressure, reduce wear
on moving parts, and ensure consistent transmission performance in both road
and track conditions.
Why Do Gearbox Gaskets, Seals
& Lock Nuts Fail or Wear Out?
Over time, these components endure significant thermal cycling, pressure changes, and exposure to fluids. Age and wear lead to material degradation and potential leaks.
Common Causes of Failure Include:
- Gasket shrinkage, cracking, or compression fatigue.
- Seal hardening from heat or exposure to aggressive fluids.
- Damaged or corroded sealing surfaces during service.
- Lock nuts loosening due to vibration or over-torqueing.
- Improper installation or reusing old sealing materials.
Failure of any of these parts can result in oil leaks, gearbox noise, or internal component damage — all of which compromise drivetrain performance and reliability.
Why Replace Your Porsche Gearbox Gaskets, Seals & Lock Nuts?
Replacing worn or leaking gaskets and seals prevents oil loss and transmission failure, while fresh locking hardware ensures secure, vibration-proof assembly. During any gearbox or differential service, new gaskets and seals should always be installed to guarantee long-term reliability.
Key Benefits:
- Prevents oil leaks and contamination of internal components.
- Maintains gearbox pressure and correct lubrication levels.
- Reduces noise, vibration, and harshness (NVH).
- Protects against long-term wear and gear damage.
- Precision fitment for Porsche manual, automatic, and PDK systems.
- Ideal for gearbox rebuilds, maintenance, and performance upgrades.
Replacing these parts as a complete kit ensures every sealing point and fastener is restored to optimal condition — protecting your investment and performance.
Highlights
- Complete Porsche gearbox gasket sets, seals, and lock nut kits.
- Manufactured from high-quality materials for strength and longevity.
- Designed for perfect fitment and superior oil retention.
- Resistant to heat, pressure, and transmission fluid degradation.
- Suitable for Porsche 911, Cayman, Boxster, Panamera, and more.
- Essential for gearbox servicing, rebuilds, and leak prevention.
