2019 Ram 1500 Transmission Fluid & Service

Quick answer

• Transmission make/model: ZF 8HP75 (850RE on V6 models)
• OEM fluid spec: Mopar ZF 8&9 Speed ATF (or equivalent Liqui Moly Top Tec 1800)
• Drain & fill capacity: ~5.5 quarts
• Full overhaul capacity: 9.0 quarts
• Filter OEM part number: Mopar 68225344AA (verify with dealer or service manual)
• Recommended service interval: 60,000 miles (severe duty) to 100,000 miles (normal duty)

Fluid type explained

The 2019 Ram 1500 is equipped with one of two excellent 8-speed automatic transmissions from German manufacturer ZF. V8-equipped trucks get the robust 8HP75, while V6 models are paired with the similar 850RE (which is a version of the ZF 8HP50 built under license by Stellantis/FCA). Both transmissions are specified with the same fluid: Mopar ZF 8&9 Speed ATF. This is a full-synthetic, low-viscosity fluid designed specifically for the complex needs of these modern, multi-clutch transmissions. Using any other fluid type, such as ATF+4, Mercon, or Dexron, will lead to shift problems and can cause catastrophic internal damage.

Service procedure

Unlike older transmissions, the ZF 8-speed does not have a traditional dipstick for checking the fluid level. The service procedure is more involved and requires the vehicle to be level and the transmission fluid to be within a specific temperature range (30-50°C or 86-122°F) to ensure an accurate reading. The filter is integrated into the transmission pan, so a filter change requires replacing the entire pan assembly. A drain and fill is the most common service method. This involves draining the old fluid from the pan, replacing the pan/filter assembly, and refilling with new fluid until it trickles out of the fill plug at the correct temperature. This typically replaces about 5.5 quarts of fluid. A full fluid exchange, which requires a specialized machine to flush the entire system including the torque converter and cooler lines, is a more thorough service but is not typically required unless the fluid is burnt or contaminated.

Service interval

Ram gives two different service intervals for the 8-speed automatic transmission, depending on how the truck is used. For normal duty (e.g., daily commuting), the recommended interval is 100,000 miles. However, for trucks subjected to severe duty, the interval is shortened to 60,000 miles. Severe duty includes frequent towing, heavy hauling, operating in dusty or off-road conditions, or extensive idling. Given the cost of transmission replacement, adhering to the severe duty interval is a wise investment for preserving transmission life, even for owners who only occasionally tow.

Common transmission problems

The ZF 8-speed family is generally considered reliable, but some common issues have been reported. Some owners experience harsh or delayed shifts, particularly between 1st and 2nd or 2nd and 3rd gears, which can sometimes be resolved with a software update from the dealer. Leaks from the plastic transmission pan or the electrical connector sleeve can also occur. In higher-mileage examples, torque converter issues can arise, sometimes presenting as a shudder or vibration at certain speeds. Regular fluid and filter services are the best preventative measure against premature wear and tear.

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