Mercedes-Benz 724.2 (8G-DCT)

8-speed dual-clutch · transverse · 2019–present

Also known as: 724.2, 8g-dct, 8g dct, 8gdct, mercedes 8-speed dual-clutch, 8g

Mercedes-Benz's transverse eight-speed dual-clutch — in the current A-Class, CLA, GLA and GLB.

It replaced the 7G-DCT in the same cars, sometimes within one model year, and the two share a great deal: both are wet dual-clutches, so neither has the low-speed judder that defines the dry units elsewhere in this catalogue. A shudder from rest on either is a fault rather than a characteristic.

The ratio count is what changed and it is what people report. Eight gears in a compact car means frequent changing and hunting between the tall ones on a light throttle — behaviour, not failure, and best settled against another example of the same model.

Its genuine faults present electrically: a gear refused, a limp mode, a code naming a solenoid or a clutch position sensor. Nothing slips first, which is what distinguishes a mechatronic problem from clutch wear.

Fluid is a control question rather than a maintenance one. The oil serves both the clutches and the hydraulics that move them, so worn fluid makes the gearbox change badly long before it makes anything fail — and on a transmission this new that is the stage almost every example is at.

Cars fitted with this gearbox

4 generations. Only where a source names the model and the generation together — a gearbox is documented as a product far more often than as a fitment, so this list is deliberately shorter than the truth.

Mercedes-Benz

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