HKS 27002-AT002 Transfer Oil Cooler Kit for GR Yaris & GR Corolla

The HKS 27002-AT002 Transfer Oil Cooler Kit is an engineered cooling solution developed specifically for the Toyota GR Yaris (GXPA16) and GR Corolla to combat transfer unit overheating during high-load and circuit driving. Without additional cooling, continuous track use causes transfer oil temperatures to spike dramatically — testing showed temperatures climbing to approximately 150°C before the vehicle's built-in protection control switches the AWD system to 2WD to prevent damage. With this HKS kit installed, oil temperatures stabilize at approximately 100°C, representing a reduction of roughly 50°C under the same conditions.

Key Features:

• Dedicated pipe-type cooler cools transfer oil independently — no impact on engine coolant, engine oil, or intercooler performance
• High-load, high-capacity electric oil pump with dedicated pump controller for precision thermal management
• Intelligent pump control: enters standby mode at low oil temperatures (high viscosity) and automatically restarts once oil reaches optimal operating temperature (~60°C)
• For vehicles equipped with the Transfer Protection Cancel Program, enables full-time AWD even during circuit driving by disabling the 2WD limp mode
• Specially designed banjo-type transfer oil outlet fitting is impact-resistant, allows oil changes without bolt removal, and includes a PT1/8 plug hole for temperature sensor installation
• Cooler bracket designed to avoid obstructing airflow to the radiator and intercooler
• Estimated installation time: approximately 8 hours

What's Included:

• Transfer cooling pipe
• High-flow electric oil pump
• Dedicated pump controller
• Oil filter
• Mounting bracket
• Hoses, wiring, and fittings

The HKS 27002-AT002 is the essential upgrade for GR Yaris and GR Corolla owners who demand sustained AWD performance on track without triggering the factory thermal protection cutoff. By keeping transfer oil temperatures in check, this kit extends oil service life and protects the transfer unit during the most demanding driving conditions.