Mopar ATF+4 is the spec fluid for the 68RFE. That's non-negotiable — do not substitute Dexron VI, Mercon V, or any generic multi-vehicle fluid. The 68RFE's clutch pack friction material and the solenoid valve seals are formulated specifically for ATF+4 chemistry. Running a non-approved fluid in this unit will cause clutch glazing within 20,000–30,000 miles and will degrade the solenoid O-ring seals, leading to internal leaks and erratic pressure control. Capacity: Total fill is approximately 17.5 quarts. A pan drain-and-fill removes roughly 6–7 quarts. A complete flush through the cooler line will exchange 14–15 quarts. For a tow vehicle, I recommend a two-stage drain-and-fill: drain, refill, drive 10 miles under light load, drain again, final fill. This exchanges approximately 80% of the fluid volume without the risks of a power flush on a high-mileage unit.
Recommended Products
Mopar ATF+4 Automatic Transmission Fluid — 1 Quart (Case of 12)
OEM-spec fluid for all 68RFE applications — buying by the case is the only practical way to stock this for production service work on Ram diesels.
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