The Mishimoto thermal bypass valve kit replaces the failure-prone factory bypass valve found across Chrysler/Dodge/Jeep/Ram applications using the W5A580 (NAG1) 5-speed automatic. The stock valve withholds transmission fluid from the cooler until operating temperature, but its thermostat can fail closed — starving the cooler and overheating the transmission. This CNC-machined billet aluminum valve includes a fully serviceable thermostat for fast cold-climate warm-up, plus an installable thermostat-bypass insert for constant cooling in hot climates, towing, or off-road use, with machined internal passages and integrated cooling fins. Black anodized, installs in under an hour.
| Brand | Mishimoto |
| Type | Transmission thermal bypass valve kit (thermostatic) |
| Transmission | W5A580 / NAG1 5-speed automatic |
| Material | CNC-machined billet aluminum, black anodized |
| Thermostat | Serviceable, with installable full-bypass insert |
| Warranty | Mishimoto Lifetime Warranty |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2005-2014 | Chrysler | 300 | 3.6L / 5.7L / SRT8 (W5A580) |
| 2006-2019 | Dodge | Charger | 3.6L / 5.7L / SRT8 (W5A580) |
| 2008-2014 | Dodge | Challenger | 3.6L / 5.7L / SRT8 (W5A580) |
| 2005-2008 | Dodge | Magnum | SE / SXT / R/T / SRT8 |
| 2011-2013 | Dodge | Durango | 3.6L / 5.7L |
| 2007-2009 | Dodge | Nitro | 3.7L / 4.0L |
| 2007-2013 | Jeep | Grand Cherokee | 3.7L / 4.7L / 5.7L / SRT8 (WK) |
| 2009-2010 | Jeep | Commander | 3.7L / 4.7L / 5.7L |
| 2008-2012 | Jeep | Liberty | 3.7L |
| 2012-2018 | Jeep | Wrangler JK | 3.6L Pentastar |
| 2012-2020 | Ram | 1500 | 3.6L / 5.7L |
| 2012-2013 | Ram | 2500 | 5.7L |
