Valvoline ULV Full Synthetic ATF Case of 6 for 10R80

Ultra-low-viscosity ATF is not the same thing as Mercon LV or Dexron VI, and the 10-speed boxes are not forgiving about it. Ford's 10R80 (2017-up F-150, Mustang, Expedition, Ranger, Navigator) and the GM 10L80 and 10L90 it shares a design with were engineered around a thinner fluid so the clutch-to-clutch shifts land where the calibration expects them. Put a heavier LV fluid in one of these and you get delayed engagement, harsh 1-2 shifts and a torque converter clutch that shudders once the fluid warms up. This is the correct viscosity class for those units, six one-quart bottles to a case.

Valvoline builds it on full synthetic base oils with friction modifiers aimed at the TCC apply and release cycle, which is where most 10-speed complaints start. The additive package targets thermal and oxidation breakdown, the two things that turn a healthy 10R80 into a shuddering one at 60,000 miles when the fluid was never changed. It also covers the GM and Ford nine-speed applications that specify a ULV fluid.

Six quarts is a drain-and-fill quantity, not a full rebuild fill. A pan drop on a 10R80 pulls roughly six to seven quarts depending on how much stays in the converter and cooler, so most techs order this case for a service, check level hot at the fill plug, and repeat the drain-and-fill a second time a few thousand miles later to dilute what stayed behind. If you are refilling a dry unit after a rebuild, plan on two cases plus what the cooler lines take.