Throughout its manufacturing history, the Ford Fusion Transmission has undergone multiple modifications to accommodate various powertrains and driving requirements. Early versions, particularly the midsize sedans from 2013 to 2016, came with the 6F series six-speed automatic, which was best represented by the 6F35. This transmission became the standard for both EcoBoost and non-turbo engines after replacing previous five-speed systems and providing performance and economy benefits.
Strengths include reasonable efficiency and smooth shifting in well‑maintained units. Owners on enthusiast forums report that with diligent fluid maintenance—draining and refilling every ~30 000 miles with high‑quality ATF like Motorcraft Mercon LV—these transmissions can perform reliably past 120 000 miles .
However, the Ford Fusion Transmission—especially the 6F35—is prone to widespread issues. Common symptoms include harsh or delayed shifts (particularly 1 → 2, 2 → 3), shift flare, jerking, lurching, unexpected clunking, and occasionally slipping gears . Many owners document experiences of sudden shaking and acceleration hesitation. In some cases, full transmission failure occurs prematurely—sometimes around 50 000 miles—and rebuilds can cost upward of US $4 500
These recurrent issues prompted class‑action lawsuits. A 2024 lawsuit (Jones et al. v. Ford) alleges the automaker knew of 6F35 defects since 2009 but failed to inform consumers. The lawsuit cites flaws in software logic, faulty hardware (e.g., torque converters, solenoids, seals), and recurring electronic control updates that were only temporary fixes
The Ford Fusion Transmission evolved through multiple generations: early ICE models had 5-speed automatics/manuals, hybrids featured an e‑CVT, and 2013–2020 models widely used the 6F-series (6F35 and 6F55). This 6-speed automatic, featuring electronic hydraulic control and compact design, aimed to balance performance and efficiency in varied engine pairings like the 1.5 L, 2.0 L EcoBoost, and 2.5 L Duratec
