Mopar Transmission Cooler Line for Ram (2019-24 2500/3500 6.7L Cummins 68RFE (with bypass valve)

This genuine Mopar transmission cooler line assembly is designed for 2019–2024 Ram 2500 and 3500 trucks with the 6.7L Cummins and 68RFE automatic transmission. It is the factory “line, TOC assembly” that carries transmission fluid to and from the cooler and incorporates the OEM-style thermal bypass valve directly into the hard line block.

The integrated bypass valve controls fluid routing during warm-up and normal operation, helping the 68RFE reach operating temperature quickly while still providing cooling capacity under load. When the original assembly is damaged, corroded, or leaking, replacing it with this updated Mopar unit restores both the physical cooler lines and the critical bypass valve function on daily driven work trucks and heavy towing rigs.

This 68359848AD assembly is the latest revision and supersedes earlier part numbers 68359848AB and 68359848AC. Pre-bent steel lines, welded brackets, and OE-style quick-connect or flare fittings allow the assembly to follow factory routing, maintain proper clearances, and bolt into the original mounting locations without modification when installed correctly.

Using a genuine Mopar line and bypass block ensures compatibility with the 6.7L Cummins/68RFE combination and avoids sealing or flow issues that can arise with universal or pieced-together repairs. This is especially important on higher-mileage trucks where previous repairs may have introduced kinks, crushed sections, or non-OE fittings that restrict fluid flow and contribute to elevated transmission temperatures.

For Ram owners and shops addressing cooler line leaks, impact damage, or known concerns with the factory bypass block, installing this updated 68359848AD assembly provides a clean, OE-correct solution. It helps keep transmission fluid circulating properly through the cooler, supports stable operating temperatures, and contributes to longer 68RFE service life under real-world work and towing conditions.