Please wait… 
Please wait while we process your order,
do not press the back button… 
Design 911 Design 911 supply Porsche parts, Porsche spares and Porsche accessories, to both retail and to the trade. Our Porsche product and accessory range includes brakes, exhausts, tyres, wheels and Porsche panels and interiors. https://www.design91.uk/images/schemaLogo.png https://www.design91.uk/images/schemaLogo.png +443456003478 https://www.design91.uk Facebook Instagram
99911332641/1
Product Information
Product Information
Manual transmission main shaft seal. 26.5 x 40 mm.
Its function is to act as a primary seal to retain oil around the input (main) shaft of a manual transmission, preventing fluid leaks and protecting driveline components.

Fits:
Porsche 911 Carrera / Turbo 1987 - 1989
Porsche 964 Carrera / Turbo 1989 - 1994
Porsche 993 Carrera / Turbo 1995 - 1998
Porsche 996 Turbo / GT2 / GT3 2001 - 2005
Porsche 997.1 Turbo / GT2 2007 - 2009
Porsche 997.2 Turbo / GT2 2010 - 2013
Porsche 996 GT3 1999 - 2005
Porsche 997 GT3 2007 - 2011

Diagram ref no 12

Application:
Manual transmission input shaft oil seal
 Cross-referenced with superseded part number: 99911332640

The input shaft seal sits around the input/main shaft where it enters the transmission case. Its job is to keep transmission fluid from leaking out and to prevent contamination from entering the gearbox. By maintaining a secure seal around the rotating shaft, this component helps preserve optimal lubrication, reduce wear, and support smooth gear operation.

In a manual transmission, the input shaft takes power from the clutch and delivers it into the gearbox. The seal must endure rotation, pressure changes, heat, and exposure to transmission fluid, forming a durable barrier that keeps oil inside while preventing dirt and debris from entering. A properly functioning input shaft seal is crucial for transmission longevity and performance.

Over time and mileage, seals can harden, crack, or lose elasticity due to heat, oil exposure, and mechanical wear. A failed input shaft seal can lead to:
 Transmission fluid leaks
 Low fluid levels
 Increased gearbox noise
 Premature wear on gears and bearings
 Potential drivetrain damage

Replacing worn or leaking seals restores proper fluid containment and protects the integrity of the transmission system, preserving performance and reducing the risk of costly repairs.

Replace the input shaft seal if you notice:
 Visible transmission fluid leaks at the bellhousing area
 Low transmission fluid levels
 Gearbox whine or unusual noises
 Transmission slipping or crunching in gear shifts
 After transmission removal or overhaul

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

99911332641
99911332641
99911332640

The product you are viewing cross references to these numbers
Related products