EDC gearbox: faults and reliability

The EDC ("Efficient Dual Clutch") gearbox is the family of dual-clutch automatic transmissions that Renault began offering in spring 2010, first in the Scénic III with the 1.5 dCi 110 diesel: it was the brand's first application of this technology. The first design, known internally as DC4, is a 6-speed dry dual clutch supplied by the German supplier Getrag, designed for engines of up to around 250 Nm of torque; under the same EDC6 trade name (6 speeds), Renault has also used a wet-clutch variant (DW6) on higher-torque engines. In 2016, with the launch of the Mégane IV and Scénic IV, Renault introduced a second generation, the EDC7 (internal code DW5), with 7 speeds and an oil-bath wet clutch, explicitly designed to fix the low-speed roughness of the dry EDC6.^[1][2][3][6]

Over the years, the EDC has been fitted to most of Renault's compact cars and small or mid-size SUVs and, later, to Dacia models too: Clio IV and V, Captur I and II, Mégane III and IV, Kadjar and Scénic III and IV, among others. Dacia took much longer to offer it: the Duster only gets the EDC6 from the 2021 facelift of its second generation, with the 1.3 TCe 150 engine. The Dacia Jogger, on the other hand, does not use this gearbox: its combustion versions are only offered with a 6-speed manual, and the hybrid variant uses a dog-clutch gearbox ("boîte à crabot") from the E-Tech family, of a completely different design.^{[4][6][7][8][9][10][11][12][13]}

EDC reliability is a recurring topic among owners. The French website fiches-auto, which specialises in car reliability, devotes an article to asking whether its faults are "serial" and collects more than twenty testimonies of clutches and complete gearboxes replaced in different models, with widely varying mileages at which the problem appeared, from just over 12,000 km to more than 160,000 km, with no single failure pattern. The specialist press itself acknowledges the limitations of the original EDC6: when testing the Scénic IV's EDC7 in 2016, L'Argus noted that the earlier gearbox suffered from "patinage à basse vitesse" (slipping at low speed) and hesitation that the new wet-clutch version corrects markedly.^[1][2]