1/4NPSM to 06AN Pair 4L80E 4L85E Trans

The 1/4NPSM to 06AN Pair 4L80E 4L85E Trans fitting is an essential adapter for transmission builders and performance enthusiasts upgrading fuel and coolant line routing on GM's legendary heavy-duty transmissions. These fittings serve as critical junction points in transmission cooler systems, where precise adaptation between different thread standards prevents leaks and ensures reliable pressure delivery under load. Whether you're rebuilding a stock unit or integrating aftermarket cooling enhancements into a modified 4L80E or 4L85E, this matched pair eliminates the need for improvised solutions and delivers OEM-grade reliability.

Each fitting in this pair converts 1/4" NPSM (National Pipe Straight Mechanical) ports to -06AN (AN6 metric) lines, accommodating the standard aluminum braided hose and crimp end configurations favored in modern transmission cooling setups. The 1/4NPSM port size is common on transmission cooler inlets and outlets, while the -06AN outlet enables use of industry-standard transmission cooler hoses and quick-disconnect fittings. Redhorse Performance's proven engineering ensures consistent thread engagement, minimal pressure drop, and compatibility with both stock and upgraded transmission coolers—critical factors when managing fluid temperatures in street or racing applications where thermal stress directly impacts shift quality and component longevity.

Serious builders tackling 4L80E or 4L85E installations—especially those retrofitting modern external coolers, upgrading to larger capacity units, or adapting transmissions to custom chassis—rely on these adapters to maintain code-correct, leak-free connections. The matched pair design means you receive both inlet and outlet fittings in one package, eliminating the guesswork and extra orders. Installation is straightforward with standard -06AN wrenches and Teflon tape on the tapered threads; these fittings integrate seamlessly into any professional cooling circuit from street trucks to competition builds.