Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
Gearbox Oil Cooler
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08

Fits:
Porsche 996 (911) Carrera 2 (1998 - 2001)
Porsche 996 (911) Carrera 4 (1999 - 2001)
Porsche 996 (911) Turbo (2001 - 2001)
Porsche 996 (911) GT3 (1999 - 2001)
Porsche 996 (911) GT2 (2001 - 2001)
Additional information: Only in combination with Tiptronic.
Click 'Zoom in' for large parts diagram.
Diagram ref no 1.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99630702001
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08

Fits:
Porsche 986 Boxster 1997-04 Tiptronic
Porsche 987 Boxster 2005-07 Tiptronic
Porsche 987C Cayman 2007-08 Tiptronic
Porsche 996 C2 / C4 >>2001 Tiptronic
Click 'Zoom in' for large parts diagram.
Diagram ref no 1.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99630701701
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
Larger than standard. 15% larger than the original for better cooling.

Fits:
Porsche 986 Boxster 1997-04 Tiptronic
Porsche 987 Boxster 2005-07 Tiptronic
Porsche 987C Cayman 2007-08 Tiptronic
Porsche 996 C2 / C4 >>2001 Tiptronic
Click 'Zoom in' for large parts diagram.
Diagram ref no 1.
The installation of a larger gearbox oil cooler for the Porsche 996, specifically for the Automatic Transmission Fluid (ATF), offers several significant benefits:
Enhanced Cooling Efficiency: A larger oil cooler increases the cooling capacity, allowing the ATF to dissipate heat more effectively. As a result, the transmission can operate at lower temperatures, preventing overheating and reducing the risk of fluid breakdown and premature wear on transmission components.
Extended Transmission Life: Lower operating temperatures due to improved cooling help prolong the lifespan of the transmission. Cooler ATF ensures that the internal components experience less stress and thermal degradation, contributing to a longer-lasting and more reliable gearbox.
Improved Performance: Optimal transmission temperature is essential for consistent and smooth gear shifts. With a larger oil cooler, the ATF maintains its viscosity and performance characteristics, promoting seamless gear changes and overall improved transmission performance.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99630701701
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08

Fits:
Porsche 986 Boxster 1997-04 Tiptronic
Porsche 987 Boxster 2005-07 Tiptronic
Porsche 987C Cayman 2007-08 Tiptronic
Porsche 996 C2 / C4 >>2001 Tiptronic
Click 'Zoom in' for large parts diagram.
Diagram ref no 1.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99630701701
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08

Fits:
Porsche 986 Boxster 1997-04 Tiptronic (A8600 / A8605 / A8620)
Porsche 987.1 Boxster 2005-08 Tiptronic
Porsche 987C.1 Cayman 2006-08 Tiptronic (A8702 / A8721)
Click 'Zoom in' for large parts diagram.
Diagram ref no 5
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
98630702000
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- 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 Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
This Porsche Genuine OE O-Ring for Gearbox Oil Cooler ATF is a precision-engineered sealing ring used within the automatic (Tiptronic) transmission cooling system. This small but critical component provides a fluid-tight seal between the gearbox oil cooler and connecting pipework.
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
Manufactured to Porsche OE standards, it ensures correct dimensions, material quality, and resistance to ATF (automatic transmission fluid), heat, and pressure.
This O-ring seals the junction between the gearbox oil cooler (heat exchanger) and its associated pipes, preventing ATF leaks and maintaining correct system pressure. By ensuring a secure seal, it allows the transmission fluid to circulate properly through the cooler, helping regulate temperature and maintain optimal gearbox performance.
Functions & Technical Role
• Fluid sealing: Prevents ATF leaks at oil cooler connections
• Pressure retention: Maintains correct hydraulic pressure within the system
• Thermal resistance: Designed to withstand high transmission temperatures
• System protection: Prevents contamination and air ingress
• OEM precision fit: Exact size and material specification for Porsche applications
Fitment / Position on car
• Fitting position: Transmission cooling system
• Location: Between gearbox oil cooler (ATF heat exchanger) and fluid pipes
• System: Automatic transmission (Tiptronic) lubrication and cooling
Although small, O-rings are critical wear items exposed to heat cycles, pressure, and fluid degradation. Over time they can harden, shrink, or crack, leading to:
• ATF leaks around the gearbox oil cooler
• Loss of transmission fluid and pressure
• Overheating of the gearbox
• Potential transmission damage
Replacing with a genuine Porsche OE O-ring ensures proper sealing, reliability, and long-term protection of the transmission system.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99970738840
The product you are viewing cross references to these numbers
- Porsche Boxster 986 2.5L 1997-99
- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005-08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- 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 Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
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
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99970738840
The product you are viewing cross references to these numbers
- Porsche Boxster 987 MKII 2.9L 2009-12
- Porsche Boxster S 987 MKII 3.4L 2009-12
- Porsche Boxster 981 2.7L 2012-16
- Porsche Boxster 981 S / GTS 3.4L 2012-16
- Porsche Boxster 981 Spyder 3.8L 2016
- Porsche Boxster 718 2.0L PDK (300 Bhp) 2017>>
- Porsche Boxster S 718 2.5L PDK (350 Bhp) 05/2017>>
- Porsche Boxster T 718 2.0L PDK (300 Bhp) 01/2019>>
- Porsche Boxster GTS 718 2.5L PDK (365 Bhp) 05/2017>>
- Porsche Boxster GTS 718 4.0L PDK (400 Bhp) 01/2019>>
- Porsche Boxster Spyder / Sypder RS 718 4.0L 01/2019>>
- Porsche Boxster 25 Years 718 4.0L Manual (400 Bhp) 01/2020>>
- Porsche Boxster 25 Years 718 4.0L PDK (400 Bhp) 01/2020>>
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12
- Porsche Cayman 2.7L 981 2013-16
- Porsche Cayman S / GTS 3.4L 981 2013-16
- Porsche Cayman GT4 3.8L 2015-16
Sold each - 4 required per car
Fits:
Porsche 987.2 Boxster - 2009 to 2012
Porsche 987.2 Cayman - 2009 to 2012
Porsche 981 Boxster - 2012 to 2016
Porsche 981 Cayman - 2013 to 2016
Porsche 718 Boxster - 2017 Onwards
Porsche 718 Cayman - 2017 Onwards
Click 'Zoom in' for large parts diagram.
Diagram ref no 30
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9P1301185A
The product you are viewing cross references to these numbers
- Porsche Boxster 987 MKII 2.9L 2009-12
- Porsche Boxster S 987 MKII 3.4L 2009-12
- Porsche Boxster 981 2.7L 2012-16
- Porsche Boxster 981 S / GTS 3.4L 2012-16
- Porsche Boxster 981 Spyder 3.8L 2016
- Porsche Boxster 718 2.0L PDK (300 Bhp) 2017>>
- Porsche Boxster S 718 2.5L PDK (350 Bhp) 05/2017>>
- Porsche Boxster T 718 2.0L PDK (300 Bhp) 01/2019>>
- Porsche Boxster GTS 718 2.5L PDK (365 Bhp) 05/2017>>
- Porsche Boxster GTS 718 4.0L PDK (400 Bhp) 01/2019>>
- Porsche Boxster Spyder / Sypder RS 718 4.0L 01/2019>>
- Porsche Boxster 25 Years 718 4.0L Manual (400 Bhp) 01/2020>>
- Porsche Boxster 25 Years 718 4.0L PDK (400 Bhp) 01/2020>>
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12
- Porsche Cayman 2.7L 981 2013-16
- Porsche Cayman S / GTS 3.4L 981 2013-16
- Porsche Cayman GT4 3.8L 2015-16

Fits:
Porsche 987.2 Boxster - 2009 to 2012
Porsche 987.2 Cayman - 2009 to 2012
Porsche 981 Boxster - 2012 to 2016
Porsche 981 Cayman - 2013 to 2016
Porsche 718 Boxster - 2017 Onwards
Porsche 718 Cayman - 2017 Onwards
Click 'Zoom in' for large parts diagram.
Diagram ref no 31
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9G230725500
The product you are viewing cross references to these numbers
-
Tiptronic / Gear oil cooler / Oil pressure line for gearbox oil cooling - A8702,A8721+ PR:249 - 987C.1 Cayman 2006-08 360-000
-
- PDK - Gearbox / heat exchanger / oil pipe / Water pipe 987C.2 Cayman 2009-12 360-000
-
- PDK - Gearbox / Heat exchanger / Oil pipe / Water pipe (Model: CG205,CG225) 981C Cayman / Cayman S 2014-16 360-000
Porsche Gearbox Oil Coolers | Maintain Optimal Transmission Temperatures for Peak Performance
A gearbox oil cooler is essential for regulating transmission temperature and ensuring consistent performance under demanding driving conditions. By circulating and cooling the gearbox oil, it prevents overheating, protects internal components, and extends the lifespan of your Porsche’s transmission.
At Design911, we supply high-quality gearbox oil coolers engineered to meet or exceed original design standards. Built from robust aluminium and high-efficiency cores, our coolers deliver superior thermal management and fluid flow — ideal for both road and track applications.
Whether you’re servicing your Porsche, replacing a leaking cooler, or upgrading for enhanced performance, our gearbox oil coolers ensure reliable cooling and protection for every mile.
What Do Gearbox Oil Coolers Do?
The gearbox oil cooler dissipates the heat generated during transmission operation, maintaining stable oil temperatures for optimal performance and protection.
Core Functions:
- Regulates gearbox oil temperature to prevent overheating.
- Ensures consistent lubrication and hydraulic performance.
- Protects seals, bearings, and internal components from heat damage.
- Enhances efficiency and performance under load.
- Extends the overall lifespan of the gearbox system.
Without a properly functioning oil cooler, the gearbox can overheat — leading to fluid breakdown, gear wear, and costly transmission damage.
Why Do Gearbox Oil Coolers Fail or Wear Out?
Gearbox oil coolers operate under high pressure and extreme heat. Over time, these conditions can cause blockages, corrosion, or leaks that reduce cooling efficiency.
Common Causes of Failure Include:
- Corrosion or internal degradation from moisture or contaminated oil.
- Leaks caused by damaged fittings or cracked cores.
- Blockages restricting oil flow and heat transfer.
- External damage from road debris or impact.
- Deterioration of hoses and seals over time.
When an oil cooler fails, symptoms can include rising gearbox temperatures, oil leaks, fluid contamination, or transmission warning lights — all signs that replacement is required.
Why Replace Your Porsche Gearbox Oil Cooler?
Replacing or upgrading your gearbox oil cooler is essential to maintain safe operating temperatures, prevent gearbox wear, and ensure consistent performance. Performance-grade oil coolers are especially beneficial for track, towing, or high-torque applications.
Key Benefits:
- Restores efficient gearbox temperature regulation.
- Prevents overheating and oil degradation.
- Improves transmission longevity and reliability.
- Reduces thermal stress on internal gearbox components.
- Designed for Porsche 911, Cayman, Boxster, Panamera, and PDK models.
- Ideal for standard servicing, rebuilds, and performance upgrades.
Regular inspection and timely replacement of the gearbox oil cooler help maintain optimal performance and avoid major gearbox repair costs.
Highlights
- Premium Porsche gearbox oil coolers engineered for reliability.
- Efficient heat dissipation for manual, Tiptronic, and PDK gearboxes.
- Durable aluminium construction with high-performance cores.
- Prevents overheating and extends gearbox lifespan.
- Perfect for maintenance, restoration, or motorsport applications.
- Direct-fit replacements compatible with a wide range of Porsche models.