The transmission fluid specification for a Ram with the 6.7L Cummins is Dexron VI automatic transmission fluid, applicable to both the older 68RFE and the newer AISIN AS69RC transmissions. Always verify the exact spec for your model year using the owner’s manual or a dealer, as configurations can vary.
Understanding the transmission options in the 6.7 Cummins
The 6.7L Cummins has appeared with two automatic transmissions over its production run: the 68RFE (roughly 2007–2012) and, starting around 2013, the AISIN AS69RC. In both cases, Ram’s documentation and owner communities generally specify Dexron VI ATF as the correct fluid. However, year-by-year differences can exist, so checking the manual or VIN-specific guidance is wise.
To help you navigate fluid choices, here is a concise guide to the commonly recommended option.
Recommended transmission fluid for the 6.7 Cummins
- Dexron VI automatic transmission fluid (ATF) — The official spec for both the 68RFE and AISIN AS69RC transmissions in Ram trucks equipped with the 6.7L Cummins.
Always use Dexron VI and avoid mixing in fluids outside the Dexron VI specification to maintain shifting quality and transmission longevity.
Fluids to avoid or not recommended
It helps to know which fluids are generally discouraged for these transmissions to prevent performance issues or damage.
- ATF+4 (Chrysler/Mopar) — not recommended for the 6.7 Cummins’ transmissions unless a very specific service bulletin or OEM approval states otherwise.
- Dexron II/III — older Dexron formulations; Dexron VI is preferred when recommended, though some older units may tolerate it with caution. Always confirm with the manual or dealer.
- Fluids not explicitly labeled Dexron VI — avoid unless the manufacturer explicitly allows them for your exact transmission and year.
When in doubt, consult your dealer or the service literature for your exact vehicle year and transmission code before performing a fluid change.
Maintenance tips for the 6.7 Cummins transmission
Regular fluid checks, proper fills, and periodic flushes per the owner’s manual help extend the life of the transmission. Tow or haul in demanding conditions with appropriate schedules, and ensure any fluid changes are performed by qualified technicians to maintain warranty coverage where applicable.
Summary
For Ram trucks powered by the 6.7L Cummins, Dexron VI automatic transmission fluid is the recommended specification for both the older 68RFE and the newer AISIN AS69RC transmissions. Always verify the exact requirement for your year and transmission code in the owner’s manual or with a dealer, and avoid fluids outside the Dexron VI specification. Regular maintenance and correct fluid choices are essential for reliable shifting and long transmission life.