O-ring for gearbox oil cooler ATF. Porsche 996 / 986 / 987 / 987C / 997.1  ❭  99970738840

O-ring for gearbox oil cooler ATF, 18.64 x 3.53 mm
An OE Match O-ring seal designed for the automatic transmission (Tiptronic) oil cooler system, ensuring a tight, leak-free connection between the gearbox oil cooler and fluid lines.
Sold individually

Fits:
Porsche 986 Boxster 1997 - 2004 Tiptronic
Porsche 987.1 Boxster 2005 - 2007 Tiptronic
Porsche 987C.1 Cayman 2007 - 2008 Tiptronic
Porsche 996 C2 / C4  / Turbo 1998 - 2005 Tiptronic
Porsche 997.1 C2 / C4  2005 - 2008 Tiptronic

Diagram ref no 2

This OE Match O-Ring for Gearbox Oil Cooler ATF is a precision-engineered sealing component designed to meet original Porsche specifications for fit, durability, and performance. This O-ring is used within the automatic transmission oil cooler system, where it forms a critical seal between the cooler and associated fluid lines.

Despite its small size, this O-ring plays a vital role in maintaining the integrity of the transmission cooling circuit. It prevents leaks of automatic transmission fluid (ATF), ensuring proper lubrication and temperature regulation of the gearbox. Without an effective seal, fluid loss can occur, potentially leading to overheating, reduced lubrication, and long-term transmission damage.

Manufactured from high-quality heat- and fluid-resistant rubber, the O-ring is designed to withstand the demanding conditions of the transmission system, including exposure to high temperatures, pressure, and aggressive fluids. It is a direct replacement for original parts and ensures reliable sealing performance in both maintenance and repair applications.

This component is commonly used on Tiptronic-equipped Porsche models, making it an essential part during transmission servicing or oil cooler replacement.

Function
• Provides a tight seal for gearbox oil cooler connections
•   Prevents ATF leaks and pressure loss
•   Maintains proper transmission cooling efficiency
•   Protects against fluid contamination and air ingress
•   Ensures reliable long-term sealing under heat and pressure

O-rings degrade over time due to heat, pressure, and exposure to transmission fluid. A worn or hardened seal can lead to ATF leaks, which may result in overheating, poor shifting performance, or serious transmission damage.

Replacing this O-ring during servicing ensures a proper seal and helps maintain the reliability and longevity of the transmission system.

When to replace
•  During gearbox or oil cooler servicing
•  Visible ATF leaks around cooler or lines
•  O-ring appears cracked, flattened, or hardened
•  Preventative replacement during transmission maintenance
•  When removing or reinstalling cooler lines

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99970738840

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