Motorcraft Mercon LV ATF 12-Quart Case for Ford 6R80

This is a full case of Motorcraft Mercon LV automatic transmission fluid, Ford part number XT-10-QLVC, twelve one-quart bottles. Mercon LV is Ford's low-viscosity ATF specification (WSS-M2C938-A) and it is the required fluid for the 6R60, 6R75 and 6R80 six-speed rear-drive transmissions, the 6R140 TorqShift behind the 6.7L Power Stroke, and the 6F35 and 6F50/6F55 transverse six-speeds. It is dyed red for leak tracing.

Buy it by the case if you are doing anything more than a drain-and-fill. A pan drop and filter on a 6R80 puts roughly six quarts back in; a proper cooler-line fluid exchange on the same unit runs through most of a twelve-quart case, and a 6R140 takes more than that. Ordering quarts one at a time is how you end up topping off a fresh rebuild with whatever is left on the shelf.

Mercon LV is not backward compatible with Mercon V and the two should not be mixed. A 4R70W, 5R55 or older 4R100 wants Mercon V; putting LV in those units will cost you converter clutch apply quality and band holding capacity. Check the dipstick or the tag before you pour. Ford also specified Mercon LV in place of the discontinued Mercon SP for 5R110W TorqShift units, so if you are servicing an older Super Duty and cannot find SP, LV is the current replacement.

Fill through the check port or the dipstick tube with a pump, run the unit through the gears, and set the level with the fluid at operating temperature - these transmissions are level-sensitive and overfilling one will aerate the fluid and cause a shudder that looks like a converter problem.