Ford 6F50

Ford's six-speed automatic for transverse engines, in production since 2006 and fitted to the larger front-drive Fords and Lincolns — the Edge, Taurus, Explorer, Flex and Fusion, and the Lincoln MKZ, MKS, MKT and MKX.

It is one half of a design Ford built jointly with General Motors, which is unusual enough to be the first thing worth saying. The two companies began the work in 2002 and spent something in the region of $720 million tooling for it; Ford builds its versions at Van Dyke in Sterling Heights and at Sharonville in Ohio, and GM builds its own at Warren. The GM half is on this site as the 6T70. A Ford Explorer and a Chevrolet Traverse of the same era are running the same architecture under two companies' part numbers — which is not something one gets to say about many gearboxes.

What this page will not do is tell you exactly which GM code yours corresponds to, because the sources disagree. One pairs the 6F50 with the 6T70 at the same torque rating; another says it is the 6T75 and rates it half as high again. The joint origin is well attested; the precise mapping is not, and a catalogue that stated one anyway would be inventing a certainty that does not exist.

The failure that runs through both halves of the design is the 3-5-R drum's spring disc — the wave plate, in the language the trade uses on the GM side. Third, fifth and reverse depend on it, and on early units it breaks. The dates the sources give differ by manufacturer: GM's revision is placed in 2009, while source B puts the vulnerable Ford window at anything built before 2012. Either way it is the build year that separates a likely candidate from an unlikely one, and when the part lets go it does not fail quietly — it comes apart inside the case and sends metal downstream.

The rest of the list follows a familiar order, and its first item is the one that starts the chain:

• The torque converter clutch, which wears out quickly. This is where the debris comes from.
• Solenoids clogged by that debris, and the loss of controlled pressure that follows.
• Bushings and the oil pump, which wear rapidly once pressure has fallen — the expensive consequence of the cheap first item.

On fluid: it takes Mercon LV, a little over ten litres of it, on an interval of roughly 60,000 km. The sequence above is the argument: the converter clutch is going to shed material whatever you do, and the fluid is the only thing standing between that material and the pump.